1191
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1 #
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2 #
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3 # Nim's Runtime Library
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4 # (c) Copyright 2015 Andreas Rumpf
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5 #
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6 # See the file "copying.txt", included in this
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7 # distribution, for details about the copyright.
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8 #
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9
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10 ## .. note:: In order to use this module, run `nimble install db_connector`.
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11 ##
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12 ## A higher level `SQLite`:idx: database wrapper. This interface
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13 ## is implemented for other databases too.
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14 ##
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15 ## Basic usage
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16 ## ===========
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17 ##
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18 ## The basic flow of using this module is:
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19 ##
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20 ## 1. Open database connection
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21 ## 2. Execute SQL query
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22 ## 3. Close database connection
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23 ##
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24 ## Parameter substitution
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25 ## ----------------------
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26 ##
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27 ## All `db_*` modules support the same form of parameter substitution.
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28 ## That is, using the `?` (question mark) to signify the place where a
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29 ## value should be placed. For example:
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30 ##
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31 ## ```Nim
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32 ## sql"INSERT INTO my_table (colA, colB, colC) VALUES (?, ?, ?)"
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33 ## ```
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34 ##
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35 ## Opening a connection to a database
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36 ## ----------------------------------
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37 ##
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38 ## ```Nim
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39 ## import db_connector/db_sqlite
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40 ##
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41 ## # user, password, database name can be empty.
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42 ## # These params are not used on db_sqlite module.
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43 ## let db = open("mytest.db", "", "", "")
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44 ## db.close()
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45 ## ```
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46 ##
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47 ## Creating a table
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48 ## ----------------
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49 ##
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50 ## ```Nim
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51 ## db.exec(sql"DROP TABLE IF EXISTS my_table")
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52 ## db.exec(sql"""CREATE TABLE my_table (
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53 ## id INTEGER,
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54 ## name VARCHAR(50) NOT NULL
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55 ## )""")
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56 ## ```
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57 ##
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58 ## Inserting data
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59 ## --------------
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60 ##
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61 ## ```Nim
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62 ## db.exec(sql"INSERT INTO my_table (id, name) VALUES (0, ?)",
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63 ## "Jack")
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64 ## ```
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65 ##
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66 ## Larger example
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67 ## --------------
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68 ##
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69 ## ```Nim
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70 ## import db_connector/db_sqlite
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71 ## import std/math
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72 ##
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73 ## let db = open("mytest.db", "", "", "")
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74 ##
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75 ## db.exec(sql"DROP TABLE IF EXISTS my_table")
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76 ## db.exec(sql"""CREATE TABLE my_table (
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77 ## id INTEGER PRIMARY KEY,
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78 ## name VARCHAR(50) NOT NULL,
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79 ## i INT(11),
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80 ## f DECIMAL(18, 10)
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81 ## )""")
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82 ##
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83 ## db.exec(sql"BEGIN")
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84 ## for i in 1..1000:
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85 ## db.exec(sql"INSERT INTO my_table (name, i, f) VALUES (?, ?, ?)",
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86 ## "Item#" & $i, i, sqrt(i.float))
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87 ## db.exec(sql"COMMIT")
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88 ##
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89 ## for x in db.fastRows(sql"SELECT * FROM my_table"):
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90 ## echo x
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91 ##
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92 ## let id = db.tryInsertId(sql"""INSERT INTO my_table (name, i, f)
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93 ## VALUES (?, ?, ?)""",
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94 ## "Item#1001", 1001, sqrt(1001.0))
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95 ## echo "Inserted item: ", db.getValue(sql"SELECT name FROM my_table WHERE id=?", id)
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96 ##
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97 ## db.close()
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98 ## ```
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99 ##
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100 ## Storing binary data example
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101 ##----------------------------
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102 ##
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103 ## ```nim
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104 ## import std/random
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105 ##
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106 ## ## Generate random float datas
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107 ## var orig = newSeq[float64](150)
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108 ## randomize()
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109 ## for x in orig.mitems:
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110 ## x = rand(1.0)/10.0
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111 ##
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112 ## let db = open("mysqlite.db", "", "", "")
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113 ## block: ## Create database
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114 ## ## Binary datas needs to be of type BLOB in SQLite
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115 ## let createTableStr = sql"""CREATE TABLE test(
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116 ## id INTEGER NOT NULL PRIMARY KEY,
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117 ## data BLOB
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118 ## )
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119 ## """
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120 ## db.exec(createTableStr)
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121 ##
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122 ## block: ## Insert data
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123 ## var id = 1
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124 ## ## Data needs to be converted to seq[byte] to be interpreted as binary by bindParams
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125 ## var dbuf = newSeq[byte](orig.len*sizeof(float64))
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126 ## copyMem(unsafeAddr(dbuf[0]), unsafeAddr(orig[0]), dbuf.len)
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127 ##
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128 ## ## Use prepared statement to insert binary data into database
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129 ## var insertStmt = db.prepare("INSERT INTO test (id, data) VALUES (?, ?)")
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130 ## insertStmt.bindParams(id, dbuf)
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131 ## let bres = db.tryExec(insertStmt)
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132 ## ## Check insert
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133 ## doAssert(bres)
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134 ## # Destroy statement
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135 ## finalize(insertStmt)
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136 ##
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137 ## block: ## Use getValue to select data
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138 ## var dataTest = db.getValue(sql"SELECT data FROM test WHERE id = ?", 1)
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139 ## ## Calculate sequence size from buffer size
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140 ## let seqSize = int(dataTest.len*sizeof(byte)/sizeof(float64))
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141 ## ## Copy binary string data in dataTest into a seq
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142 ## var res: seq[float64] = newSeq[float64](seqSize)
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143 ## copyMem(unsafeAddr(res[0]), addr(dataTest[0]), dataTest.len)
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144 ##
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145 ## ## Check datas obtained is identical
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146 ## doAssert res == orig
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147 ##
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148 ## db.close()
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149 ## ```
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150 ##
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151 ##
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152 ## Note
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153 ## ====
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154 ## This module does not implement any ORM features such as mapping the types from the schema.
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155 ## Instead, a `seq[string]` is returned for each row.
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156 ##
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157 ## The reasoning is as follows:
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158 ## 1. it's close to what many DBs offer natively (`char**`:c:)
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159 ## 2. it hides the number of types that the DB supports
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160 ## (int? int64? decimal up to 10 places? geo coords?)
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161 ## 3. it's convenient when all you do is to forward the data to somewhere else (echo, log, put the data into a new query)
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162 ##
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163 ## See also
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164 ## ========
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165 ##
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166 ## * `db_odbc module <db_odbc.html>`_ for ODBC database wrapper
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167 ## * `db_mysql module <db_mysql.html>`_ for MySQL database wrapper
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168 ## * `db_postgres module <db_postgres.html>`_ for PostgreSQL database wrapper
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169
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170
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171 import ./sqlite3, macros
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172
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173 import ./db_common
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174 export db_common
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175
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176 import private/dbutils
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177
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178 import std/private/[since]
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179 when defined(nimPreviewSlimSystem):
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180 import std/assertions
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181
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182 type
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183 DbConn* = PSqlite3 ## Encapsulates a database connection.
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184 Row* = seq[string] ## A row of a dataset. `NULL` database values will be
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185 ## converted to an empty string.
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186 InstantRow* = PStmt ## A handle that can be used to get a row's column
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187 ## text on demand.
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188 SqlPrepared* = distinct PStmt ## a identifier for the prepared queries
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189
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190 proc bindParam*(ps: SqlPrepared, paramIdx: int, val: int32) {.since: (1, 3).}
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191 proc bindParam*(ps: SqlPrepared, paramIdx: int, val: int64) {.since: (1, 3).}
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192 proc bindParam*(ps: SqlPrepared, paramIdx: int, val: int) {.since: (1, 3).}
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193 proc bindParam*(ps: SqlPrepared, paramIdx: int, val: float64) {.since: (1, 3).}
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194 proc bindNull*(ps: SqlPrepared, paramIdx: int) {.since: (1, 3).}
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195 proc bindParam*(ps: SqlPrepared, paramIdx: int, val: string, copy = true) {.since: (1, 3).}
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196 proc bindParam*(ps: SqlPrepared, paramIdx: int,val: openArray[byte], copy = true) {.since: (1, 3).}
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197
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198 proc dbError*(db: DbConn) {.noreturn.} =
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199 ## Raises a `DbError` exception.
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200 ##
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201 ## **Examples:**
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202 ## ```Nim
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203 ## let db = open("mytest.db", "", "", "")
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204 ## if not db.tryExec(sql"SELECT * FROM not_exist_table"):
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205 ## dbError(db)
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206 ## db.close()
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207 ## ```
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208 var e: ref DbError
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209 new(e)
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210 e.msg = $sqlite3.errmsg(db)
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211 raise e
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212
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213 proc dbQuote*(s: string): string =
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214 ## Escapes the `'` (single quote) char to `''`.
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215 ## Because single quote is used for defining `VARCHAR` in SQL.
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216 runnableExamples:
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217 doAssert dbQuote("'") == "''''"
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218 doAssert dbQuote("A Foobar's pen.") == "'A Foobar''s pen.'"
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219
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220 result = "'"
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221 for c in items(s):
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222 if c == '\'': add(result, "''")
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223 else: add(result, c)
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224 add(result, '\'')
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225
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226 proc dbFormat(formatstr: SqlQuery, args: varargs[string]): string =
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227 dbFormatImpl(formatstr, dbQuote, args)
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228
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229 proc prepare*(db: DbConn; q: string): SqlPrepared {.since: (1, 3).} =
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230 ## Creates a new `SqlPrepared` statement.
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231 if prepare_v2(db, q, q.len.cint,result.PStmt, nil) != SQLITE_OK:
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232 discard finalize(result.PStmt)
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233 dbError(db)
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234
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235 proc tryExec*(db: DbConn, query: SqlQuery,
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236 args: varargs[string, `$`]): bool {.
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237 tags: [ReadDbEffect, WriteDbEffect].} =
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238 ## Tries to execute the query and returns `true` if successful, `false` otherwise.
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239 ##
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240 ## **Examples:**
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241 ## ```Nim
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242 ## let db = open("mytest.db", "", "", "")
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243 ## if not db.tryExec(sql"SELECT * FROM my_table"):
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244 ## dbError(db)
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245 ## db.close()
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246 ## ```
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247 assert(not db.isNil, "Database not connected.")
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248 var q = dbFormat(query, args)
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249 var stmt: sqlite3.PStmt
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250 if prepare_v2(db, q.cstring, q.len.cint, stmt, nil) == SQLITE_OK:
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251 let x = step(stmt)
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252 if x in [SQLITE_DONE, SQLITE_ROW]:
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253 result = finalize(stmt) == SQLITE_OK
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254 else:
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255 discard finalize(stmt)
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256 result = false
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257
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258 proc tryExec*(db: DbConn, stmtName: SqlPrepared): bool {.
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259 tags: [ReadDbEffect, WriteDbEffect].} =
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260 let x = step(stmtName.PStmt)
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261 if x in [SQLITE_DONE, SQLITE_ROW]:
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262 result = true
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263 else:
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264 discard finalize(stmtName.PStmt)
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265 result = false
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266
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267 proc exec*(db: DbConn, query: SqlQuery, args: varargs[string, `$`]) {.
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268 tags: [ReadDbEffect, WriteDbEffect].} =
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269 ## Executes the query and raises a `DbError` exception if not successful.
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270 ##
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271 ## **Examples:**
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272 ## ```Nim
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273 ## let db = open("mytest.db", "", "", "")
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274 ## try:
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275 ## db.exec(sql"INSERT INTO my_table (id, name) VALUES (?, ?)",
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276 ## 1, "item#1")
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277 ## except:
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278 ## stderr.writeLine(getCurrentExceptionMsg())
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279 ## finally:
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280 ## db.close()
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281 ## ```
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282 if not tryExec(db, query, args): dbError(db)
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283
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284 macro untypedLen(args: varargs[untyped]): int =
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285 newLit(args.len)
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286
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287 macro bindParams*(ps: SqlPrepared, params: varargs[untyped]): untyped {.since: (1, 3).} =
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288 let bindParam = bindSym("bindParam", brOpen)
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289 let bindNull = bindSym("bindNull")
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290 let preparedStatement = genSym()
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291 result = newStmtList()
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292 # Store `ps` in a temporary variable. This prevents `ps` from being evaluated every call.
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293 result.add newNimNode(nnkLetSection).add(newIdentDefs(preparedStatement, newEmptyNode(), ps))
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294 for idx, param in params:
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295 if param.kind != nnkNilLit:
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296 result.add newCall(bindParam, preparedStatement, newIntLitNode idx + 1, param)
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297 else:
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298 result.add newCall(bindNull, preparedStatement, newIntLitNode idx + 1)
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299
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300
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301 template exec*(db: DbConn, stmtName: SqlPrepared,
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302 args: varargs[typed]): untyped =
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303 when untypedLen(args) > 0:
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304 if reset(stmtName.PStmt) != SQLITE_OK:
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305 dbError(db)
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306 if clear_bindings(stmtName.PStmt) != SQLITE_OK:
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307 dbError(db)
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308 stmtName.bindParams(args)
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309 if not tryExec(db, stmtName): dbError(db)
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310
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311 proc newRow(L: int): Row =
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312 newSeq(result, L)
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313 for i in 0..L-1: result[i] = ""
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314
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315 proc setupQuery(db: DbConn, query: SqlQuery,
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316 args: varargs[string]): PStmt =
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317 assert(not db.isNil, "Database not connected.")
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318 var q = dbFormat(query, args)
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319 if prepare_v2(db, q.cstring, q.len.cint, result, nil) != SQLITE_OK: dbError(db)
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320
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321 proc setupQuery(db: DbConn, stmtName: SqlPrepared): SqlPrepared {.since: (1, 3).} =
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322 assert(not db.isNil, "Database not connected.")
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323 result = stmtName
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324
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325 proc setRow(stmt: PStmt, r: var Row, cols: cint) =
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326 for col in 0'i32..cols-1:
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327 let cb = column_bytes(stmt, col)
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328 setLen(r[col], cb) # set capacity
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329 if column_type(stmt, col) == SQLITE_BLOB:
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330 copyMem(addr(r[col][0]), column_blob(stmt, col), cb)
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331 else:
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332 setLen(r[col], 0)
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333 let x = column_text(stmt, col)
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334 if not isNil(x): add(r[col], x)
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335
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336 iterator fastRows*(db: DbConn, query: SqlQuery,
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337 args: varargs[string, `$`]): Row {.tags: [ReadDbEffect].} =
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338 ## Executes the query and iterates over the result dataset.
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339 ##
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340 ## This is very fast, but potentially dangerous. Use this iterator only
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341 ## if you require **ALL** the rows.
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342 ##
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343 ## **Note:** Breaking the `fastRows()` iterator during a loop will cause the
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344 ## next database query to raise a `DbError` exception `unable to close due
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345 ## to ...`.
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346 ##
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347 ## **Examples:**
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348 ##
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349 ## ```Nim
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350 ## let db = open("mytest.db", "", "", "")
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351 ##
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352 ## # Records of my_table:
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353 ## # | id | name |
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354 ## # |----|----------|
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355 ## # | 1 | item#1 |
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356 ## # | 2 | item#2 |
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357 ##
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358 ## for row in db.fastRows(sql"SELECT id, name FROM my_table"):
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359 ## echo row
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360 ##
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361 ## # Output:
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362 ## # @["1", "item#1"]
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363 ## # @["2", "item#2"]
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364 ##
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365 ## db.close()
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366 ## ```
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367 var stmt = setupQuery(db, query, args)
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368 var L = (column_count(stmt))
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369 var result = newRow(L)
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370 try:
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371 while step(stmt) == SQLITE_ROW:
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372 setRow(stmt, result, L)
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373 yield result
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374 finally:
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375 if finalize(stmt) != SQLITE_OK: dbError(db)
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376
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377 iterator fastRows*(db: DbConn, stmtName: SqlPrepared): Row
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378 {.tags: [ReadDbEffect,WriteDbEffect], since: (1, 3).} =
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379 discard setupQuery(db, stmtName)
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380 var L = (column_count(stmtName.PStmt))
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381 var result = newRow(L)
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382 try:
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383 while step(stmtName.PStmt) == SQLITE_ROW:
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384 setRow(stmtName.PStmt, result, L)
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385 yield result
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386 except:
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387 dbError(db)
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388
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389 iterator instantRows*(db: DbConn, query: SqlQuery,
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390 args: varargs[string, `$`]): InstantRow
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391 {.tags: [ReadDbEffect].} =
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392 ## Similar to `fastRows iterator <#fastRows.i,DbConn,SqlQuery,varargs[string,]>`_
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393 ## but returns a handle that can be used to get column text
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394 ## on demand using `[]`. Returned handle is valid only within the iterator body.
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395 ##
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396 ## **Examples:**
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397 ##
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398 ## ```Nim
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399 ## let db = open("mytest.db", "", "", "")
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400 ##
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401 ## # Records of my_table:
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402 ## # | id | name |
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403 ## # |----|----------|
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404 ## # | 1 | item#1 |
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405 ## # | 2 | item#2 |
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406 ##
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407 ## for row in db.instantRows(sql"SELECT * FROM my_table"):
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408 ## echo "id:" & row[0]
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409 ## echo "name:" & row[1]
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410 ## echo "length:" & $len(row)
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411 ##
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412 ## # Output:
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413 ## # id:1
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414 ## # name:item#1
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415 ## # length:2
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416 ## # id:2
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417 ## # name:item#2
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418 ## # length:2
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419 ##
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420 ## db.close()
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421 ## ```
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422 var stmt = setupQuery(db, query, args)
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423 try:
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424 while step(stmt) == SQLITE_ROW:
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425 yield stmt
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426 finally:
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427 if finalize(stmt) != SQLITE_OK: dbError(db)
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428
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429 iterator instantRows*(db: DbConn, stmtName: SqlPrepared): InstantRow
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430 {.tags: [ReadDbEffect,WriteDbEffect], since: (1, 3).} =
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431 var stmt = setupQuery(db, stmtName).PStmt
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432 try:
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433 while step(stmt) == SQLITE_ROW:
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434 yield stmt
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435 except:
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436 dbError(db)
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437
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438 proc toTypeKind(t: var DbType; x: int32) =
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439 case x
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440 of SQLITE_INTEGER:
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441 t.kind = dbInt
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442 t.size = 8
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443 of SQLITE_FLOAT:
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444 t.kind = dbFloat
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445 t.size = 8
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446 of SQLITE_BLOB: t.kind = dbBlob
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447 of SQLITE_NULL: t.kind = dbNull
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448 of SQLITE_TEXT: t.kind = dbVarchar
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449 else: t.kind = dbUnknown
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450
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451 proc setColumns(columns: var DbColumns; x: PStmt) =
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452 let L = column_count(x)
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453 setLen(columns, L)
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454 for i in 0'i32 ..< L:
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455 columns[i].name = $column_name(x, i)
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456 columns[i].typ.name = $column_decltype(x, i)
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|
457 toTypeKind(columns[i].typ, column_type(x, i))
|
|
458 columns[i].tableName = $column_table_name(x, i)
|
|
459
|
|
460 iterator instantRows*(db: DbConn; columns: var DbColumns; query: SqlQuery,
|
|
461 args: varargs[string, `$`]): InstantRow
|
|
462 {.tags: [ReadDbEffect].} =
|
|
463 ## Similar to `instantRows iterator <#instantRows.i,DbConn,SqlQuery,varargs[string,]>`_,
|
|
464 ## but sets information about columns to `columns`.
|
|
465 ##
|
|
466 ## **Examples:**
|
|
467 ##
|
|
468 ## ```Nim
|
|
469 ## let db = open("mytest.db", "", "", "")
|
|
470 ##
|
|
471 ## # Records of my_table:
|
|
472 ## # | id | name |
|
|
473 ## # |----|----------|
|
|
474 ## # | 1 | item#1 |
|
|
475 ## # | 2 | item#2 |
|
|
476 ##
|
|
477 ## var columns: DbColumns
|
|
478 ## for row in db.instantRows(columns, sql"SELECT * FROM my_table"):
|
|
479 ## discard
|
|
480 ## echo columns[0]
|
|
481 ##
|
|
482 ## # Output:
|
|
483 ## # (name: "id", tableName: "my_table", typ: (kind: dbNull,
|
|
484 ## # notNull: false, name: "INTEGER", size: 0, maxReprLen: 0, precision: 0,
|
|
485 ## # scale: 0, min: 0, max: 0, validValues: @[]), primaryKey: false,
|
|
486 ## # foreignKey: false)
|
|
487 ##
|
|
488 ## db.close()
|
|
489 ## ```
|
|
490 var stmt = setupQuery(db, query, args)
|
|
491 setColumns(columns, stmt)
|
|
492 try:
|
|
493 while step(stmt) == SQLITE_ROW:
|
|
494 yield stmt
|
|
495 finally:
|
|
496 if finalize(stmt) != SQLITE_OK: dbError(db)
|
|
497
|
|
498 proc `[]`*(row: InstantRow, col: int32): string {.inline.} =
|
|
499 ## Returns text for given column of the row.
|
|
500 ##
|
|
501 ## See also:
|
|
502 ## * `instantRows iterator <#instantRows.i,DbConn,SqlQuery,varargs[string,]>`_
|
|
503 ## example code
|
|
504 $column_text(row, col)
|
|
505
|
|
506 proc unsafeColumnAt*(row: InstantRow, index: int32): cstring {.inline.} =
|
|
507 ## Returns cstring for given column of the row.
|
|
508 ##
|
|
509 ## See also:
|
|
510 ## * `instantRows iterator <#instantRows.i,DbConn,SqlQuery,varargs[string,]>`_
|
|
511 ## example code
|
|
512 column_text(row, index)
|
|
513
|
|
514 proc len*(row: InstantRow): int32 {.inline.} =
|
|
515 ## Returns number of columns in a row.
|
|
516 ##
|
|
517 ## See also:
|
|
518 ## * `instantRows iterator <#instantRows.i,DbConn,SqlQuery,varargs[string,]>`_
|
|
519 ## example code
|
|
520 column_count(row)
|
|
521
|
|
522 proc getRow*(db: DbConn, query: SqlQuery,
|
|
523 args: varargs[string, `$`]): Row {.tags: [ReadDbEffect].} =
|
|
524 ## Retrieves a single row. If the query doesn't return any rows, this proc
|
|
525 ## will return a `Row` with empty strings for each column.
|
|
526 ##
|
|
527 ## **Examples:**
|
|
528 ##
|
|
529 ## ```Nim
|
|
530 ## let db = open("mytest.db", "", "", "")
|
|
531 ##
|
|
532 ## # Records of my_table:
|
|
533 ## # | id | name |
|
|
534 ## # |----|----------|
|
|
535 ## # | 1 | item#1 |
|
|
536 ## # | 2 | item#2 |
|
|
537 ##
|
|
538 ## doAssert db.getRow(sql"SELECT id, name FROM my_table"
|
|
539 ## ) == Row(@["1", "item#1"])
|
|
540 ## doAssert db.getRow(sql"SELECT id, name FROM my_table WHERE id = ?",
|
|
541 ## 2) == Row(@["2", "item#2"])
|
|
542 ##
|
|
543 ## # Returns empty.
|
|
544 ## doAssert db.getRow(sql"INSERT INTO my_table (id, name) VALUES (?, ?)",
|
|
545 ## 3, "item#3") == @[]
|
|
546 ## doAssert db.getRow(sql"DELETE FROM my_table WHERE id = ?", 3) == @[]
|
|
547 ## doAssert db.getRow(sql"UPDATE my_table SET name = 'ITEM#1' WHERE id = ?",
|
|
548 ## 1) == @[]
|
|
549 ## db.close()
|
|
550 ## ```
|
|
551 var stmt = setupQuery(db, query, args)
|
|
552 var L = (column_count(stmt))
|
|
553 result = newRow(L)
|
|
554 if step(stmt) == SQLITE_ROW:
|
|
555 setRow(stmt, result, L)
|
|
556 if finalize(stmt) != SQLITE_OK: dbError(db)
|
|
557
|
|
558 proc getAllRows*(db: DbConn, query: SqlQuery,
|
|
559 args: varargs[string, `$`]): seq[Row] {.tags: [ReadDbEffect].} =
|
|
560 ## Executes the query and returns the whole result dataset.
|
|
561 ##
|
|
562 ## **Examples:**
|
|
563 ##
|
|
564 ## ```Nim
|
|
565 ## let db = open("mytest.db", "", "", "")
|
|
566 ##
|
|
567 ## # Records of my_table:
|
|
568 ## # | id | name |
|
|
569 ## # |----|----------|
|
|
570 ## # | 1 | item#1 |
|
|
571 ## # | 2 | item#2 |
|
|
572 ##
|
|
573 ## doAssert db.getAllRows(sql"SELECT id, name FROM my_table") == @[Row(@["1", "item#1"]), Row(@["2", "item#2"])]
|
|
574 ## db.close()
|
|
575 ## ```
|
|
576 result = @[]
|
|
577 for r in fastRows(db, query, args):
|
|
578 result.add(r)
|
|
579
|
|
580 proc getAllRows*(db: DbConn, stmtName: SqlPrepared): seq[Row]
|
|
581 {.tags: [ReadDbEffect,WriteDbEffect], since: (1, 3).} =
|
|
582 result = @[]
|
|
583 for r in fastRows(db, stmtName):
|
|
584 result.add(r)
|
|
585
|
|
586 iterator rows*(db: DbConn, query: SqlQuery,
|
|
587 args: varargs[string, `$`]): Row {.tags: [ReadDbEffect].} =
|
|
588 ## Similar to `fastRows iterator <#fastRows.i,DbConn,SqlQuery,varargs[string,]>`_,
|
|
589 ## but slower and safe.
|
|
590 ##
|
|
591 ## **Examples:**
|
|
592 ##
|
|
593 ## ```Nim
|
|
594 ## let db = open("mytest.db", "", "", "")
|
|
595 ##
|
|
596 ## # Records of my_table:
|
|
597 ## # | id | name |
|
|
598 ## # |----|----------|
|
|
599 ## # | 1 | item#1 |
|
|
600 ## # | 2 | item#2 |
|
|
601 ##
|
|
602 ## for row in db.rows(sql"SELECT id, name FROM my_table"):
|
|
603 ## echo row
|
|
604 ##
|
|
605 ## ## Output:
|
|
606 ## ## @["1", "item#1"]
|
|
607 ## ## @["2", "item#2"]
|
|
608 ##
|
|
609 ## db.close()
|
|
610 ## ```
|
|
611 for r in fastRows(db, query, args): yield r
|
|
612
|
|
613 iterator rows*(db: DbConn, stmtName: SqlPrepared): Row
|
|
614 {.tags: [ReadDbEffect,WriteDbEffect], since: (1, 3).} =
|
|
615 for r in fastRows(db, stmtName): yield r
|
|
616
|
|
617 proc getValue*(db: DbConn, query: SqlQuery,
|
|
618 args: varargs[string, `$`]): string {.tags: [ReadDbEffect].} =
|
|
619 ## Executes the query and returns the first column of the first row of the
|
|
620 ## result dataset. Returns `""` if the dataset contains no rows or the database
|
|
621 ## value is `NULL`.
|
|
622 ##
|
|
623 ## **Examples:**
|
|
624 ##
|
|
625 ## ```Nim
|
|
626 ## let db = open("mytest.db", "", "", "")
|
|
627 ##
|
|
628 ## # Records of my_table:
|
|
629 ## # | id | name |
|
|
630 ## # |----|----------|
|
|
631 ## # | 1 | item#1 |
|
|
632 ## # | 2 | item#2 |
|
|
633 ##
|
|
634 ## doAssert db.getValue(sql"SELECT name FROM my_table WHERE id = ?",
|
|
635 ## 2) == "item#2"
|
|
636 ## doAssert db.getValue(sql"SELECT id, name FROM my_table") == "1"
|
|
637 ## doAssert db.getValue(sql"SELECT name, id FROM my_table") == "item#1"
|
|
638 ##
|
|
639 ## db.close()
|
|
640 ## ```
|
|
641 var stmt = setupQuery(db, query, args)
|
|
642 if step(stmt) == SQLITE_ROW:
|
|
643 let cb = column_bytes(stmt, 0)
|
|
644 if cb == 0:
|
|
645 result = ""
|
|
646 else:
|
|
647 if column_type(stmt, 0) == SQLITE_BLOB:
|
|
648 result.setLen(cb)
|
|
649 copyMem(addr(result[0]), column_blob(stmt, 0), cb)
|
|
650 else:
|
|
651 result = newStringOfCap(cb)
|
|
652 add(result, column_text(stmt, 0))
|
|
653 else:
|
|
654 result = ""
|
|
655 if finalize(stmt) != SQLITE_OK: dbError(db)
|
|
656
|
|
657 proc getValue*(db: DbConn, stmtName: SqlPrepared): string
|
|
658 {.tags: [ReadDbEffect,WriteDbEffect], since: (1, 3).} =
|
|
659 var stmt = setupQuery(db, stmtName).PStmt
|
|
660 if step(stmt) == SQLITE_ROW:
|
|
661 let cb = column_bytes(stmt, 0)
|
|
662 if cb == 0:
|
|
663 result = ""
|
|
664 else:
|
|
665 if column_type(stmt, 0) == SQLITE_BLOB:
|
|
666 result.setLen(cb)
|
|
667 copyMem(addr(result[0]), column_blob(stmt, 0), cb)
|
|
668 else:
|
|
669 result = newStringOfCap(cb)
|
|
670 add(result, column_text(stmt, 0))
|
|
671 else:
|
|
672 result = ""
|
|
673
|
|
674 proc tryInsertID*(db: DbConn, query: SqlQuery,
|
|
675 args: varargs[string, `$`]): int64
|
|
676 {.tags: [WriteDbEffect], raises: [DbError].} =
|
|
677 ## Executes the query (typically "INSERT") and returns the
|
|
678 ## generated ID for the row or -1 in case of an error.
|
|
679 ##
|
|
680 ## **Examples:**
|
|
681 ##
|
|
682 ## ```Nim
|
|
683 ## let db = open("mytest.db", "", "", "")
|
|
684 ## db.exec(sql"CREATE TABLE my_table (id INTEGER, name VARCHAR(50) NOT NULL)")
|
|
685 ##
|
|
686 ## doAssert db.tryInsertID(sql"INSERT INTO not_exist_table (id, name) VALUES (?, ?)",
|
|
687 ## 1, "item#1") == -1
|
|
688 ## db.close()
|
|
689 ## ```
|
|
690 assert(not db.isNil, "Database not connected.")
|
|
691 var q = dbFormat(query, args)
|
|
692 var stmt: sqlite3.PStmt
|
|
693 result = -1
|
|
694 if prepare_v2(db, q.cstring, q.len.cint, stmt, nil) == SQLITE_OK:
|
|
695 if step(stmt) == SQLITE_DONE:
|
|
696 result = last_insert_rowid(db)
|
|
697 if finalize(stmt) != SQLITE_OK:
|
|
698 result = -1
|
|
699 else:
|
|
700 discard finalize(stmt)
|
|
701
|
|
702 proc insertID*(db: DbConn, query: SqlQuery,
|
|
703 args: varargs[string, `$`]): int64 {.tags: [WriteDbEffect].} =
|
|
704 ## Executes the query (typically "INSERT") and returns the
|
|
705 ## generated ID for the row.
|
|
706 ##
|
|
707 ## Raises a `DbError` exception when failed to insert row.
|
|
708 ## For Postgre this adds `RETURNING id` to the query, so it only works
|
|
709 ## if your primary key is named `id`.
|
|
710 ##
|
|
711 ## **Examples:**
|
|
712 ##
|
|
713 ## ```Nim
|
|
714 ## let db = open("mytest.db", "", "", "")
|
|
715 ## db.exec(sql"CREATE TABLE my_table (id INTEGER, name VARCHAR(50) NOT NULL)")
|
|
716 ##
|
|
717 ## for i in 0..2:
|
|
718 ## let id = db.insertID(sql"INSERT INTO my_table (id, name) VALUES (?, ?)", i, "item#" & $i)
|
|
719 ## echo "LoopIndex = ", i, ", InsertID = ", id
|
|
720 ##
|
|
721 ## # Output:
|
|
722 ## # LoopIndex = 0, InsertID = 1
|
|
723 ## # LoopIndex = 1, InsertID = 2
|
|
724 ## # LoopIndex = 2, InsertID = 3
|
|
725 ##
|
|
726 ## db.close()
|
|
727 ## ```
|
|
728 result = tryInsertID(db, query, args)
|
|
729 if result < 0: dbError(db)
|
|
730
|
|
731 proc tryInsert*(db: DbConn, query: SqlQuery, pkName: string,
|
|
732 args: varargs[string, `$`]): int64
|
|
733 {.tags: [WriteDbEffect], raises: [DbError], since: (1, 3).} =
|
|
734 ## same as tryInsertID
|
|
735 tryInsertID(db, query, args)
|
|
736
|
|
737 proc insert*(db: DbConn, query: SqlQuery, pkName: string,
|
|
738 args: varargs[string, `$`]): int64
|
|
739 {.tags: [WriteDbEffect], since: (1, 3).} =
|
|
740 ## same as insertId
|
|
741 result = tryInsert(db, query, pkName, args)
|
|
742 if result < 0: dbError(db)
|
|
743
|
|
744 proc execAffectedRows*(db: DbConn, query: SqlQuery,
|
|
745 args: varargs[string, `$`]): int64 {.
|
|
746 tags: [ReadDbEffect, WriteDbEffect].} =
|
|
747 ## Executes the query (typically "UPDATE") and returns the
|
|
748 ## number of affected rows.
|
|
749 ##
|
|
750 ## **Examples:**
|
|
751 ##
|
|
752 ## ```Nim
|
|
753 ## let db = open("mytest.db", "", "", "")
|
|
754 ##
|
|
755 ## # Records of my_table:
|
|
756 ## # | id | name |
|
|
757 ## # |----|----------|
|
|
758 ## # | 1 | item#1 |
|
|
759 ## # | 2 | item#2 |
|
|
760 ##
|
|
761 ## doAssert db.execAffectedRows(sql"UPDATE my_table SET name = 'TEST'") == 2
|
|
762 ##
|
|
763 ## db.close()
|
|
764 ## ```
|
|
765 exec(db, query, args)
|
|
766 result = changes(db)
|
|
767
|
|
768 proc execAffectedRows*(db: DbConn, stmtName: SqlPrepared): int64
|
|
769 {.tags: [ReadDbEffect, WriteDbEffect],since: (1, 3).} =
|
|
770 exec(db, stmtName)
|
|
771 result = changes(db)
|
|
772
|
|
773 proc close*(db: DbConn) {.tags: [DbEffect].} =
|
|
774 ## Closes the database connection.
|
|
775 ##
|
|
776 ## **Examples:**
|
|
777 ## ```Nim
|
|
778 ## let db = open("mytest.db", "", "", "")
|
|
779 ## db.close()
|
|
780 ## ```
|
|
781 if sqlite3.close(db) != SQLITE_OK: dbError(db)
|
|
782
|
|
783 proc open*(connection, user, password, database: string): DbConn {.
|
|
784 tags: [DbEffect].} =
|
|
785 ## Opens a database connection. Raises a `DbError` exception if the connection
|
|
786 ## could not be established.
|
|
787 ##
|
|
788 ## **Note:** Only the `connection` parameter is used for `sqlite`.
|
|
789 ##
|
|
790 ## **Examples:**
|
|
791 ## ```Nim
|
|
792 ## try:
|
|
793 ## let db = open("mytest.db", "", "", "")
|
|
794 ## ## do something...
|
|
795 ## ## db.getAllRows(sql"SELECT * FROM my_table")
|
|
796 ## db.close()
|
|
797 ## except:
|
|
798 ## stderr.writeLine(getCurrentExceptionMsg())
|
|
799 ## ```
|
|
800 var db: DbConn
|
|
801 if sqlite3.open(connection, db) == SQLITE_OK:
|
|
802 result = db
|
|
803 else:
|
|
804 dbError(db)
|
|
805
|
|
806 proc setEncoding*(connection: DbConn, encoding: string): bool {.
|
|
807 tags: [DbEffect].} =
|
|
808 ## Sets the encoding of a database connection, returns `true` for
|
|
809 ## success, `false` for failure.
|
|
810 ##
|
|
811 ## **Note:** The encoding cannot be changed once it's been set.
|
|
812 ## According to SQLite3 documentation, any attempt to change
|
|
813 ## the encoding after the database is created will be silently
|
|
814 ## ignored.
|
|
815 exec(connection, sql"PRAGMA encoding = ?", [encoding])
|
|
816 result = connection.getValue(sql"PRAGMA encoding") == encoding
|
|
817
|
|
818 proc finalize*(sqlPrepared:SqlPrepared) {.discardable, since: (1, 3).} =
|
|
819 discard finalize(sqlPrepared.PStmt)
|
|
820
|
|
821 template dbBindParamError*(paramIdx: int, val: varargs[untyped]) =
|
|
822 ## Raises a `DbError` exception.
|
|
823 var e: ref DbError
|
|
824 new(e)
|
|
825 e.msg = "error binding param in position " & $paramIdx
|
|
826 raise e
|
|
827
|
|
828 proc bindParam*(ps: SqlPrepared, paramIdx: int, val: int32) {.since: (1, 3).} =
|
|
829 ## Binds a int32 to the specified paramIndex.
|
|
830 if bind_int(ps.PStmt, paramIdx.int32, val) != SQLITE_OK:
|
|
831 dbBindParamError(paramIdx, val)
|
|
832
|
|
833 proc bindParam*(ps: SqlPrepared, paramIdx: int, val: int64) {.since: (1, 3).} =
|
|
834 ## Binds a int64 to the specified paramIndex.
|
|
835 if bind_int64(ps.PStmt, paramIdx.int32, val) != SQLITE_OK:
|
|
836 dbBindParamError(paramIdx, val)
|
|
837
|
|
838 proc bindParam*(ps: SqlPrepared, paramIdx: int, val: int) {.since: (1, 3).} =
|
|
839 ## Binds a int to the specified paramIndex.
|
|
840 when sizeof(int) == 8:
|
|
841 bindParam(ps, paramIdx, val.int64)
|
|
842 else:
|
|
843 bindParam(ps, paramIdx, val.int32)
|
|
844
|
|
845 proc bindParam*(ps: SqlPrepared, paramIdx: int, val: float64) {.since: (1, 3).} =
|
|
846 ## Binds a 64bit float to the specified paramIndex.
|
|
847 if bind_double(ps.PStmt, paramIdx.int32, val) != SQLITE_OK:
|
|
848 dbBindParamError(paramIdx, val)
|
|
849
|
|
850 proc bindNull*(ps: SqlPrepared, paramIdx: int) {.since: (1, 3).} =
|
|
851 ## Sets the bindparam at the specified paramIndex to null
|
|
852 ## (default behaviour by sqlite).
|
|
853 if bind_null(ps.PStmt, paramIdx.int32) != SQLITE_OK:
|
|
854 dbBindParamError(paramIdx)
|
|
855
|
|
856 proc bindParam*(ps: SqlPrepared, paramIdx: int, val: string, copy = true) {.since: (1, 3).} =
|
|
857 ## Binds a string to the specified paramIndex.
|
|
858 ## if copy is true then SQLite makes its own private copy of the data immediately
|
|
859 if bind_text(ps.PStmt, paramIdx.int32, val.cstring, val.len.int32, if copy: SQLITE_TRANSIENT else: SQLITE_STATIC) != SQLITE_OK:
|
|
860 dbBindParamError(paramIdx, val)
|
|
861
|
|
862 proc bindParam*(ps: SqlPrepared, paramIdx: int,val: openArray[byte], copy = true) {.since: (1, 3).} =
|
|
863 ## binds a blob to the specified paramIndex.
|
|
864 ## if copy is true then SQLite makes its own private copy of the data immediately
|
|
865 let len = val.len
|
|
866 if bind_blob(ps.PStmt, paramIdx.int32, val[0].unsafeAddr, len.int32, if copy: SQLITE_TRANSIENT else: SQLITE_STATIC) != SQLITE_OK:
|
|
867 dbBindParamError(paramIdx, val)
|
|
868
|
|
869 when not defined(testing) and isMainModule:
|
|
870 var db = open(":memory:", "", "", "")
|
|
871 exec(db, sql"create table tbl1(one varchar(10), two smallint)", [])
|
|
872 exec(db, sql"insert into tbl1 values('hello!',10)", [])
|
|
873 exec(db, sql"insert into tbl1 values('goodbye', 20)", [])
|
|
874 var p1 = db.prepare "create table tbl2(one varchar(10), two smallint)"
|
|
875 exec(db, p1)
|
|
876 finalize(p1)
|
|
877 var p2 = db.prepare "insert into tbl2 values('hello!',10)"
|
|
878 exec(db, p2)
|
|
879 finalize(p2)
|
|
880 var p3 = db.prepare "insert into tbl2 values('goodbye', 20)"
|
|
881 exec(db, p3)
|
|
882 finalize(p3)
|
|
883 #db.query("create table tbl1(one varchar(10), two smallint)")
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884 #db.query("insert into tbl1 values('hello!',10)")
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885 #db.query("insert into tbl1 values('goodbye', 20)")
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|
886 for r in db.rows(sql"select * from tbl1", []):
|
|
887 echo(r[0], r[1])
|
|
888 for r in db.instantRows(sql"select * from tbl1", []):
|
|
889 echo(r[0], r[1])
|
|
890 var p4 = db.prepare "select * from tbl2"
|
|
891 for r in db.rows(p4):
|
|
892 echo(r[0], r[1])
|
|
893 finalize(p4)
|
|
894 var i5 = 0
|
|
895 var p5 = db.prepare "select * from tbl2"
|
|
896 for r in db.instantRows(p5):
|
|
897 inc i5
|
|
898 echo(r[0], r[1])
|
|
899 assert i5 == 2
|
|
900 finalize(p5)
|
|
901
|
|
902 for r in db.rows(sql"select * from tbl2", []):
|
|
903 echo(r[0], r[1])
|
|
904 for r in db.instantRows(sql"select * from tbl2", []):
|
|
905 echo(r[0], r[1])
|
|
906 var p6 = db.prepare "select * from tbl2 where one = ? "
|
|
907 p6.bindParams("goodbye")
|
|
908 var rowsP3 = 0
|
|
909 for r in db.rows(p6):
|
|
910 rowsP3 = 1
|
|
911 echo(r[0], r[1])
|
|
912 assert rowsP3 == 1
|
|
913 finalize(p6)
|
|
914
|
|
915 var p7 = db.prepare "select * from tbl2 where two=?"
|
|
916 p7.bindParams(20'i32)
|
|
917 when sizeof(int) == 4:
|
|
918 p7.bindParams(20)
|
|
919 var rowsP = 0
|
|
920 for r in db.rows(p7):
|
|
921 rowsP = 1
|
|
922 echo(r[0], r[1])
|
|
923 assert rowsP == 1
|
|
924 finalize(p7)
|
|
925
|
|
926 exec(db, sql"CREATE TABLE photos(ID INTEGER PRIMARY KEY AUTOINCREMENT, photo BLOB)")
|
|
927 var p8 = db.prepare "INSERT INTO photos (ID,PHOTO) VALUES (?,?)"
|
|
928 var d = "abcdefghijklmnopqrstuvwxyz"
|
|
929 p8.bindParams(1'i32, "abcdefghijklmnopqrstuvwxyz")
|
|
930 exec(db, p8)
|
|
931 finalize(p8)
|
|
932 var p10 = db.prepare "INSERT INTO photos (ID,PHOTO) VALUES (?,?)"
|
|
933 p10.bindParams(2'i32,nil)
|
|
934 exec(db, p10)
|
|
935 exec( db, p10, 3, nil)
|
|
936 finalize(p10)
|
|
937 for r in db.rows(sql"select * from photos where ID = 1", []):
|
|
938 assert r[1].len == d.len
|
|
939 assert r[1] == d
|
|
940 var i6 = 0
|
|
941 for r in db.rows(sql"select * from photos where ID = 3", []):
|
|
942 i6 = 1
|
|
943 assert i6 == 1
|
|
944 var p9 = db.prepare("select * from photos where PHOTO is ?")
|
|
945 p9.bindParams(nil)
|
|
946 var rowsP2 = 0
|
|
947 for r in db.rows(p9):
|
|
948 rowsP2 = 1
|
|
949 echo(r[0], repr r[1])
|
|
950 assert rowsP2 == 1
|
|
951 finalize(p9)
|
|
952
|
|
953 db_sqlite.close(db)
|