目录

sql标签

​编辑

where标签

set标签

foreach标签

批量增加

批量删除

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将基础SQL语句中重复性高的增加它的复用性，使得sql语句的灵活性更强

sql标签<sql>

<sql id="text">select * from user</sql><select id="selectAll" resultType="user"><include refid="text"></include></select>

where标签

注意事项：where会自动忽略前后缀比如and与or

<select id="selectByIdAndPwd" resultType="user"><include refid="text"></include><where><if test="id!=null">id=#{id}</if><if test="pwd!=null">and password=#{pwd}</if></where>
​</select>

set标签

注意事项：set中满足条件的if会自动忽略后缀，比如“，”

<update id="updateUser" parameterType="user">update user<set><if test="name!=null">name=#{name},</if><if test="password!=null">password=#{password}</if></set>where id=#{id}</update>

foreach标签

批量增加

<!--collection传入的容器类型；open以什么为开始，close以什么为结束，separator分割item传入的容器中的元素-->
<insert id="addForeach" parameterType="user">insert into user(name,password,sex)  values<foreach collection="list" item="user" separator=",">(#{user.name},#{user.password},#{user.sex})</foreach></insert>

批量删除

<delete id="delForeach" parameterType="int">delete from user where id in<foreach collection="array" open="(" close=")" separator="," item="id">#{id}</foreach></delete>