我使用PDO连接到sqlite3,但由于某些原因我无法使外键工作。根据文档,这个“PRAGMA short_column_names = 1”应该可以实现。我这样做:
$con = new PDO('sqlite:z:/testing.db');
$res = $con->exec('PRAGMA foreign_keys=ON');
var_dump($res);die();
返回给我0.我尝试使用外键创建实际表,但它不起作用。 对SQLite3类的直接请求虽然有效:
$con = new SQLite3('z:/testing.db');
$con->exec('PRAGMA foreign_keys = ON;');
var_dump($con->query('PRAGMA foreign_keys;')->fetchArray());
此reutrns数组(2){[0] => int(1)[“foreign_keys”] => int(1)}
根据SQLite3 :: version(),我有sqlite版本3.7.7.1。我的PHP版本是5.3.18,在Windows上运行。
请帮助我让它与PDO一起运行。谢谢!
答案 0 :(得分:7)
我不知道应该使用PDO发出PRAGMA short_column_names=1;
以便外键约束与SQLite一起使用的想法。
尝试一下:
PRAGMA foreign_keys = ON;
它应该导致以下结果:
<?php
// SQL for creating database structure
$databaseSql = <<<SQL
CREATE TABLE `user` (
`id` INTEGER PRIMARY KEY AUTOINCREMENT,
`name` TEXT NOT NULL,
UNIQUE( `name` )
);
CREATE TABLE `userProfile` (
`userId` INTEGER NOT NULL CONSTRAINT `userProfile_userId` REFERENCES `user`( `id` ) ON UPDATE CASCADE ON DELETE CASCADE,
`image` TEXT NOT NULL
);
SQL;
// SQL for inserting dummy data
$dataSql = <<<SQL
INSERT INTO `user` VALUES( 1, "John" );
INSERT INTO `user` VALUES( 2, "Mary" );
INSERT INTO `user` VALUES( 3, "Joe" );
INSERT INTO `userProfile` VALUES( 1, "/images/john.jpg" );
INSERT INTO `userProfile` VALUES( 2, "/images/mary.jpg" );
INSERT INTO `userProfile` VALUES( 3, "/images/joe.jpg" );
SQL;
// create a temporary SQLite instance in memory
$db = new PDO( 'sqlite::memory:', null, null, array(
PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
PDO::ATTR_EMULATE_PREPARES => false
) );
// activate use of foreign key constraints
$db->exec( 'PRAGMA foreign_keys = ON;' );
// create database
$db->exec( $databaseSql );
// insert dummy data
$db->exec( $dataSql );
// should dump 3 records
var_dump( $db->query( 'SELECT * FROM `userProfile`;' )->fetchAll() );
// delete 1 user, cascade deleting 1 userProfile as well
$db->exec( 'DELETE FROM `user` WHERE `id` = 1;' );
// should dump 2 records
var_dump( $db->query( 'SELECT * FROM `userProfile`;' )->fetchAll() );