java - MyBatis java 和 MySql 局部变量

Question

我是 Java 世界的新手。我有一个简单查询的问题:

<insert id="create" parameterType="models.entities.CategoryEntity">

    set @catId := (select categoryId from Categories limit 1);
     insert into Categories(CategoryId, Title, LeftValue, RightValue)
    values(@catId, 'Test in', 1,2);
   ....
</insert>

当我试图用 mybatis 运行它时，它只是失败了:

PersistenceException occured : ### 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 'insert into Categories(CategoryId, Title, LeftValue, RightValue) values(' at line 2 ### The error may involve Category.create-Inline ### The error occurred while setting parameters ### 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 'insert into Categories(CategoryId, Title, LeftValue, RightValue) values(' at line 2

如果我删除这一行:

set @catId := (select categoryId from Categories limit 1);

然后一切正常。我究竟做错了什么？是jdbc还是mybatis的问题？如何在 mybatis 中使用 mysql @variables？有人有在 mybatis 中使用 MySql 局部变量的例子吗？

Answer 1

我找到了如何让它发挥作用。只需设置数据源属性 allowMultiQueries=true

jdbc:mysql://localhost:3306/DBS?allowMultiQueries=true