Question

我有以下声明，我需要更新数据库中的条目：

<update id="setAsDefault" >
  START TRANSACTION;
    UPDATE cms_wall SET is_default = FALSE WHERE owner = #{ownerId} AND is_default= TRUE;
    UPDATE cms_wall SET is_default = TRUE  WHERE brand = #{brandId};
   COMMIT;
</update>

这两个陈述都是单独的。此外，如果我在mysql中手动输入它们，它们会合并。当我尝试从ibatis运行时，我收到以下错误：

### Error updating database.  Cause:com.mysql.jdbc.exceptions.jdbc4.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 'UPDATE cms_wall SET is_default = FALSE WHERE owner = '123_test_user_' at line 2
### The error may involve defaultParameterMap
### The error occurred while setting parameters
### SQL: START TRANSACTION;         UPDATE cms_wall SET is_default = FALSE WHERE owner= ? AND is_default= TRUE;         UPDATE cms_wall SET is_default = TRUE  WHERE brand = ?;        COMMIT;
### Cause: com.mysql.jdbc.exceptions.jdbc4.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 'UPDATE cms_wall SET is_default = FALSE WHERE owner = '123_test_user_' at line 2

Answer 1

使用if测试语句更清晰：

<update id="setAsDefault" >
  START TRANSACTION;
  <if test="ownerId != null">
      UPDATE cms_wall SET is_default = FALSE WHERE owner = #{ownerId} AND is_default= TRUE;
  </if>
  <if test="brandId != null">
      UPDATE cms_wall SET is_default = TRUE  WHERE brand = #{brandId};
  </if>
   COMMIT;
</update>

Answer 2

这应该有效：

UPDATE cms_wall SET is_default = IF(owner = #{ownerId} AND is_default=TRUE,FALSE,IF(brand = #{brandId},TRUE,is_default));

如何在ibatis中组合sql语句？

2 个答案: