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mybatis利用collection传递多参数子查询
153浏览 · 2023-12-01 14:42:15
mybatis利用collection传递多参数子查询的步骤如下：
1.在mapper.xml文件中定义一个select语句，其中使用了collection标签来传递多个参数，例如：
```xml
<select id="selectByCollection" parameterType="java.util.Map" resultMap="BaseResultMap">
select * from table_name where column in
<foreach collection="list" item="item" open="(" separator="," close=")">
#{item}
</foreach>
</select>
2.在Java代码中调用该select语句，并传递一个Map类型的参数，其中包含一个名为list的List类型的值，例如：
```java
List<Integer> list = new ArrayList<>();
list.add(1);
list.add(2);
Map<String, Object> map = new HashMap<>();
map.put("list", list);
List<Table> result = sqlSession.selectList("selectByCollection", map);
这样就可以利用collection传递多个参数进行子查询了。
相关问题
Mybatis中，可以使用`collection`标签将集合类型的参数传递给SQL语句。具体的用法如下：
1. 定义一个包含集合类型参数的方法，例如：
```java
public List<User> selectUsersByIds(@Param("ids") List<Integer> ids);
```
MyBatis allows you to perform collection subqueries, which can be useful when you need to retrieve related data for a collection of records. Collection subqueries are typically used in scenarios where you have a one-to-many or many-to-many relationship between tables.
To implement a collection subquery in MyBatis, you can use the `<collection>` element within your result mapping. Here's an example:
```xml
<resultMap id="userMap" type="User">
<id property="id" column="user_id" />
<result property="name" column="user_name" />
<collection property="orders" ofType="Order">
<id property="id" column="order_id" />
<result property="product" column="product_name" />
</collection>
</resultMap>