将参数传递给MyBatis @Select [英] Passing parameter to MyBatis @Select

问题描述

我正在写我的拳头MyBatis应用程序，但我坚持使用@Select.我不知道我的@Select定义出了什么问题，一切似乎都很好，但是出现了Parameter not found异常.

I am writing my fist MyBatis application and I stuck around @Select. I do not know what is the problem with my @Select definition, everything seems fine but I got a Parameter not found exception.

当我将参数传递给我的@Insert语句时，我遵循了相同的模式，并且可以正常工作.

I have followed the same pattern when I pass parameters to my my @Insert statement and it works without problem.

我使用MyBatis 3.4.2.

I use MyBatis 3.4.2.

这是我的@Select:

@Select("SELECT * "
        + "FROM configuration "
        + "WHERE key_name = #{key} AND "
        +       "(#{userId} IS NULL AND user_id IS NULL) OR user_id = #{userId} AND "
        +       "status = 1")
Configuration findByKeyAndUserId(String key, Long userId);

我得到的例外情况:

org.apache.ibatis.exceptions.PersistenceException: 
### Error querying database.  Cause: org.apache.ibatis.binding.BindingException: Parameter 'key' not found. Available parameters are [arg1, arg0, param1, param2]
### Cause: org.apache.ibatis.binding.BindingException: Parameter 'key' not found. Available parameters are [arg1, arg0, param1, param2]

推荐答案

当您传递单个参数对象时，可以直接通过地图的getter或键集访问属性.当您想在方法中传递多个参数时，必须使用注释命名参数:

When you pass a single parameter object, properties are accessed directly through getter or key set for a map. When you want to pass multiple parameters in the method, you have to name the parameters with annotation:

Configuration findByKeyAndUserId(@Param("key") String key, @Param("userId") Long userId);

这种基于注释的语法实际上就像键值映射.密钥由@Param提供.您为参数变量选择的名称不可见.

This annotation based syntax actually behave like a key-value map. Keys are provided by @Param. The name you choose for parameter variables are not visible.

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