How to update a large amount of data using MyBatis?

2 years ago
Liam
2 minutes

MyBatis offers various ways to update a large amount of data.

  1. You can use the foreach element in SQL statements to iterate through a collection and perform update operations during the iteration process. For example:
<update id="updateBatch" parameterType="java.util.List">
  UPDATE table_name
  SET column1 = #{list[0].column1},
      column2 = #{list[0].column2}
  WHERE id = #{list[0].id}
  <foreach collection="list" item="item" index="index" separator="UNION ALL">
    SELECT #{item.column1}, #{item.column2}, #{item.id}
  </foreach>
</update>
  1. Using dynamic SQL allows the generation of SQL statements based on conditions to update a large amount of data. For example:
<update id="updateBatch" parameterType="java.util.Map">
  UPDATE table_name
  <set>
    <if test="column1 != null">column1 = #{column1},</if>
    <if test="column2 != null">column2 = #{column2},</if>
  </set>
  WHERE id IN
  <foreach collection="ids" item="id" open="(" separator="," close=")">
    #{id}
  </foreach>
</update>
  1. By using batch operations, MyBatis offers a BatchExecutor interface that allows for executing multiple update operations at once. For example:
try (SqlSession sqlSession = sqlSessionFactory.openSession(ExecutorType.BATCH)) {
  YourMapper mapper = sqlSession.getMapper(YourMapper.class);
  for (YourEntity entity : entities) {
    mapper.update(entity);
  }
  sqlSession.commit();
}

The above are some common ways to update a large amount of data, and the appropriate method can be chosen based on specific circumstances during actual use.

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