从jdbc中删除MySQL上的表

Question

从 jdbc 删除表时出现问题

我有一个。通过先前准备的语句从多个表中删除记录的 jar

我是这样做的：

-- SQL
delete from tabla_a using tabla_a join tabla_c join tabla_b join tabla_d
where tabla_a.tabla_c_id = tabla_c.id and tabla_c.tabla_b_id = tabla_b.id
and tabla_b.tabla_d_id = tabla_d.id and tabla_d.field = 2;

注意：where (?) is an integer

// Java
conn = DriverManager.getConnection(dsn, user, pass);
stmt = conn.createStatement();
int rows = stmt.executeUpdate(query);

不起作用不会删除任何记录，我直接将 SQL 测试到 MySQL并正常工作。

Answer 1

尝试改用PreparedStatement，并设置参数。沿着这些思路：

conn = DriverManager.getConnection(dsn, user, pass);
stmt = conn.prepareStatement(query);
stmt.setInt(1, 2);
int rows = stmt.executeUpdate();