[英]SQLite foreign key problems
I've two tables that has defined as below; 我有两个定义如下的表; When i delete row from RELHOSPOL from the SQL Manager with executing a DELETE command, it nulls the necessary rows at the USER table. 当我通过执行DELETE命令从SQL Manager的RELHOSPOL中删除行时,它将使USER表上的必要行为空。 Whenever I delete a row from application with the method written below, it only deletes row from RELHOSPOL, and does not SET NULL the necessary rows at USER table. 每当我使用下面编写的方法从应用程序中删除行时,它只会从RELHOSPOL中删除行,而不会在USER表中将必要的行设置为NULL。 What is the missing point ? 遗漏点是什么?
CREATE TABLE [USER] (
[ID] INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
[GROUPID] INTEGER CONSTRAINT [FK_USER_GID] REFERENCES [GROUP]([ID]) ON DELETE SET NULL ON UPDATE CASCADE,
[HOSPITALID] INTEGER,
[POLIKLINIKID] INTEGER,
[NAME] VARCHAR(50) NOT NULL,
[LOGINID] VARCHAR(15) NOT NULL,
[EMAIL] VARCHAR(50) NOT NULL,
[PASSWORD] VARCHAR(32) NOT NULL,
CONSTRAINT [FK_USER_RELHOSPOL] FOREIGN KEY([HOSPITALID], [POLIKLINIKID]) REFERENCES [RELHOSPOL]([HOSPITALID], [POLIKLINIKID]) ON DELETE SET NULL ON UPDATE CASCADE);
CREATE UNIQUE INDEX [AS] ON [USER] ([LOGINID]);
CREATE UNIQUE INDEX [AS1] ON [USER] ([EMAIL]));
CREATE TABLE [RELHOSPOL] (
[ID] INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
[HOSPITALID] INTEGER,
[POLIKLINIKID] INTEGER);
CREATE UNIQUE INDEX [UNIQUE_RELHOSPOL] ON [RELHOSPOL] ([HOSPITALID], [POLIKLINIKID]);
public void deletePoliklinikFromHospital(int hospitalId, int poliklinikId) throws SQLException{
String query = "DELETE FROM [RELHOSPOL] WHERE (HOSPITALID = ? AND POLIKLINIKID = ?)";
try {
PreparedStatement statement = db.prepareStatement(query);
statement.setInt(1, hospitalId);
statement.setInt(2, poliklinikId);
statement.executeUpdate();
} catch (SQLException e) {
throw new SQLException(e.getMessage());
}
}
You need to turn on enforcement of foreign keys , which is off by default for reasons of backward compatibility. 您需要打开外键强制实施,由于向后兼容,默认情况下该功能处于关闭状态。 It's a per-connection configuration option. 这是每个连接的配置选项。 Add this as one of the first things you do once you've made a Connection
: 添加为你做的,一旦你已经做出了第一件事情之一Connection
:
PRAGMA foreign_keys = on;
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