Question

我有两张表定义如下;当我通过执行DELETE命令从SQL管理器中删除RELHOSPOL中的行时，它会使USER表中的必要行为空。每当我使用下面编写的方法从应用程序中删除一行时，它只会删除RELHOSPOL中的行，并且不会在USER表中设置必要的行。缺少什么？

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());
        }
    }

Answer 1

您需要turn on enforcement of foreign keys，默认情况下由于向后兼容性而关闭。这是一个每连接配置选项。将此添加为您在创建Connection后首先执行的操作之一：

PRAGMA foreign_keys = on;

SQLite外键问题

1 个答案: