在mysql5.5上通过JDBC创建触发器时出错

Question

这是我的代码:

triggerBuilder.append("DROP TRIGGER IF EXISTS `insert_associated_inquiry`; ");
triggerBuilder.append(" DELIMITER %% ");

triggerBuilder.append(" CREATE TRIGGER insert_associated_inquiry BEFORE UPDATE ON inquiry ");
triggerBuilder.append(" FOR EACH ROW Begin ");    

triggerBuilder.append(" insert into associated_inquiries(inquiry_id , subject , content , inquiry_date , preferred_date ) " );
triggerBuilder.append("values");
        triggerBuilder.append(" ( " );
            triggerBuilder.append(" OLD.id , ");
            triggerBuilder.append(" OLD.subject , " );
            triggerBuilder.append(" OLD.content , " );
            triggerBuilder.append(" OLD.created_on , " );
            triggerBuilder.append(" OLD.preffered_date " );
        triggerBuilder.append(" ) ; ");

triggerBuilder.append(" END %% ");

triggerBuilder.append(" DELIMITER ; ");

con.createStatement().execute(triggerBuilder.toString());

这是抛出的错误:

 com.mysql.jdbc.exceptions.MySQLSyntaxErrorException: You have an error in your SQL syntax;
 check the manual that corresponds to your MySQL server version for the right 
 syntax to use near 'DELIMITER %%  CREATE TRIGGER insert_associated_inquiry 
 BEFORE UPDATE ON inquiry ' at line 1

可能是这个错误的原因和解决方案.求助.谢谢.

Answer 1

不要在JDBC和MySQL中使用分隔符.分隔符仅由MySQL控制台使用,以便它可以判断您输入的触发器,存储过程等何时结束.在JDBC中,将整个SQL字符串放在一起,然后将其发送到数据库.因为您可以控制SQL何时被发送到数据库,所以不需要使用分隔符.

我删除了两DELIMITER行并使用了%%代码中的分隔符,并将DROP TRIGGER命令分别发送到数据库.我留下的代码如下:

con.createStatement().execute("DROP TRIGGER IF EXISTS `insert_associated_inquiry`");

triggerBuilder.append(" CREATE TRIGGER insert_associated_inquiry BEFORE UPDATE ON inquiry ");
triggerBuilder.append(" FOR EACH ROW Begin ");    

triggerBuilder.append(" insert into associated_inquiries(inquiry_id , subject , content , inquiry_date , preferred_date ) " );
triggerBuilder.append("values");
        triggerBuilder.append(" ( " );
            triggerBuilder.append(" OLD.id , ");
            triggerBuilder.append(" OLD.subject , " );
            triggerBuilder.append(" OLD.content , " );
            triggerBuilder.append(" OLD.created_on , " );
            triggerBuilder.append(" OLD.preffered_date " );
        triggerBuilder.append(" ) ; ");

triggerBuilder.append(" END ");

con.createStatement().execute(triggerBuilder.toString());

此代码似乎有效,因为无论触发器是否已存在,我都可以无错误地运行此代码.如果先前没有触发器,则创建它.