没有使用MySQL Connector/J的服务器端准备好的语句 [英] No server-side prepared statements using MySQL Connector/J

问题描述

据我了解，MySQL 5.1支持服务器端准备好的语句.因此，以下代码应准备一次该语句，然后执行10次:

From what I understand, MySQL 5.1 supports server-side prepared statements. Therefore the following code should prepare the statement once, and execute it 10 times:

    Connection conn = ds.getConnection();
    PreparedStatement stmt = conn.prepareStatement("SELECT COUNT(*) FROM users WHERE user_id=?");
    for (int i=0; i<10; i++)
    {
        stmt.setString(1, "FOO"+i);
        ResultSet res = stmt.executeQuery();
        res.close();
    }
    stmt.close();
    conn.close();

我在mysqld日志中看到的是直接执行的查询:

What I see instead in the mysqld log is the query being executed directly:

    SELECT @@session.tx_isolation
    SELECT USER()
    SELECT COUNT(*) FROM users WHERE user_id='FOO0'
    SELECT COUNT(*) FROM users WHERE user_id='FOO1'
    SELECT COUNT(*) FROM users WHERE user_id='FOO2'
            ...

我也在协议日志中每次都看到完整发送的查询(使用tcpdump).

I see the query sent in the full each time in the protocol logs too (using tcpdump).

使用Connector/J 5.1.12和MySQL 5.1.44. JDBC URL中没有有趣的JDBC选项.直接进入驱动程序进行测试，没有池.

Using Connector/J 5.1.12 and MySQL 5.1.44. No funny JDBC options in the JDBC URL. Going straight to the driver for this test, no pool.

为什么不准备陈述?

推荐答案

除非使用连接参数useServerPrepStmts=true打开真实的服务器端语句，否则Connector/J驱动程序将在本地处理准备好的语句.

The Connector/J driver handles prepared statements locally unless you turn on real server side statements using the connection parameter useServerPrepStmts=true.

http://dev. mysql.com/doc/refman/5.0/en/connector-j-reference-configuration-properties.html

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