Mybatis-3(常用标签组合)

一.标签概览

• 1.查询,where+if组合

select
    a.id
 from t_user a
<where>
	<if test="email != null and email != ''">
		and a.email like CONCAT('%', #{email}, '%')
	if>
	<if test="sex != null ">
		and a.sex = #{sex}
	if>
where>

• 2.更新,update+set组合

   	
   update t_user
<set>
	<if test="userName != null">
		userName = #{userName,jdbcType=VARCHAR},
	if>
	<if test="realName != null">
		realName = #{realName,jdbcType=VARCHAR},
	if>
set>
where id = #{id,jdbcType=INTEGER} 

• 3.插入,insert+trem组合

	
insert into t_user
	<trim prefix="(" suffix=")" suffixOverrides="," >
		<if test="id != null">
			id,
		if>
		<if test="userName != null">
			userName,
		if>
	trim>
	
	<trim prefix="values (" suffix=")" suffixOverrides=",">
		<if test="id != null">
			#{id,jdbcType=INTEGER},
		if>
		<if test="userName != null">
			#{userName,jdbcType=VARCHAR},
		if>
	trim>

• 4.forEach标签

  查询,参数为arry或者list时

select
	a.id
	from t_user a
	where a.userName in
	<foreach collection="array" open="(" close=")" item="userName" separator=",">
		#{userName}
	foreach> 

select
	a.id
	from t_user a
	where a.userName in
	<foreach collection="list" open="(" close=")" item="userName" separator=",">
		#{userName}
	foreach> 

批量插入1

insert into t_user (userName,position_id)
	values
	<foreach collection="list" separator="," item="user">
		(
		#{user.userName,jdbcType=VARCHAR},
		#{user.position.id,jdbcType=INTEGER}
		)
	foreach>

批量插入2

使用BATCH类型的excutor

示例参考跳转: