mybaits判断map
时间: 2023-07-17 10:03:23 浏览: 52
MyBatis provides a way to conditionally include or exclude SQL fragments based on the values in a Map. This can be achieved using the `<if>` element in MyBatis XML configuration.
Here's an example of how you can use the `<if>` element to conditionally include a WHERE clause based on the values in a Map:
```xml
<select id="getUserList" resultType="User">
SELECT * FROM users
<where>
<if test="name != null and name != ''">
AND name = #{name}
</if>
<if test="age != null">
AND age = #{age}
</if>
</where>
</select>
```
In this example, the `getUserList` query selects all users from the `users` table. The `<where>` element is used to dynamically generate the WHERE clause based on the conditions specified within the `<if>` elements.
The `test` attribute in the `<if>` element specifies the condition that needs to be met for the SQL fragment inside the `<if>` element to be included. In this case, if the `name` parameter in the input Map is not null and not an empty string, the corresponding condition `name = #{name}` will be included in the WHERE clause.
Similarly, the condition `age = #{age}` will be included if the `age` parameter is not null.
You can customize and modify the conditions within the `<if>` elements based on your specific requirements.
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