MyBatis add, modify, delete in batches through annotations

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The following will demonstrate that Mybatis will add, modify, and delete entity users in batches through annotations.

First, the database entity DO

1  public  class User implements Serializable {
 2      private Long id;      // User ID 
3      private String name;    // User name 
4      private Integer age;     // User age 
5      .......
 6 }

Second, the database operation

　　2.1, insert users in batches

1     @Insert("<script>"  +
2                 "insert into user(id, name, age) VALUES " +
3                 "<foreach collection='list' item='item' index='index' separator=','> " +
4                     "(#{item.id},#{item.name},#{item.age}) " +
5                 "</foreach>" +
6             "</script>")
7     void batchInsert(@Param("list")List<User> list); //批量添加用户

 

　　2.2, modify users in batches

1     @Update({"<script>"  +
2                 "<foreach collection='list' item='item' index='index' open='(' separator=',' close=')'> " +
3                     "update user set name= #{item.name}, age= #{item.age} " +
4                     "where id = #{item.id} " +
5                 "</foreach>" +
6             "</script>"})
7     void batchUpdate(@Param("list")List<User> list);//批量修改用户

 

　　2.3, delete users in batches

1      @Delete ("<script>" +
 2                  "delete from user where id in" +
 3                  "<foreach collection = 'array' item = 'id' open = '(' separator = ',' close = ')'> "+
 4                      " # {id} "+
 5                  " </ foreach> "+
 6              " </ script> " )
 7      void batchDelete ( long [] ids); // Delete users in batches
 8      
9      // ☆☆☆ How to get long [] ids? ? ?
10      // 1. Get the collection of the user to be deleted 
11      List <User>     // 2, get long [] ids 13           according to the collection
 // friends, if you are still using SAO operations such as traversal, creating arrays, etc .... you are OUT
 14           // let ’s see how the jdk8 stream is engaged Of: 
15          List <Long> idList = user.stream.map (User :: getId) .collect (Collectors.toList ()); // Get the id collection      
16          long [] ids = idList.stream.mapToLong (i-> i) .toArray (); // The obtained long [] ids 
17         
18          is realized in two steps (actually one step), is it not fragrant ? ? ?

 

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2020/04/13 early