1.sql語句標籤 <sql></sql><include></include>
<sql id="someFied">
name,password,age,sex,phone
</sql>
<select id="selectData">
select
<include refid="someFied">
from xxx
where id=#{id}
</select>
2.if標籤 if判斷
<select id="selectData" resultType="Product">
select * from product
<if test="name!=null">
where name like concat('%',#{name},'%')
</if>
</select>
3.<when> <otherwise>標籤
Mybatis裏面沒有else標籤，但是可以使用when otherwise標籤來達到這樣的效果
<select id="listProduct" resultType="Product">
SELECT * FROM product_
<where>
<choose>
<when test="name != null">
and name like concat('%',#{name},'%'</when>
<when test="price !=null and price != 0">
and price > #{price}</when> <otherwise>
and id >1</otherwise>
</choose>
</where>
</select>
4.where標籤 where標籤裏面成立就執行，如果不成立就可以忽略wherer標籤
<select id="selectData" resultType="Product">
select * from product
<where>
<if test="name!=null">
and name like concat('%',#{name},'%')
</if>
<if test="price!=null and price!=0">
and price>#{price}
</if>
</where>
</select>
5.set標籤 與where標籤類似,成立時執行，不成立時可以忽略
update的sql語句中會碰到多個字段，可以使用set標籤
<update id="updataData" parameterType="Product">
update prduct
<set>
<if test="name!=null">name=#{name},</if>
<if test="price!=null">price=#{price}</if>
</set>
where id=#{id}
</update>
6.foreach標籤，通常用於in這樣的語法裏
接收一個List集合時使用foreach標籤循環遍歷
<select if ="selectData" resultType="Product">
select * from produce
where id in
<foreach item="item" index="index" collection="list">
open="(" separator="," close=")">
#{item}
</foreach>
</select>
7.bind標籤，就像是再做一次字符串拼接，網上也有說綁定，差不多意思
<select id="listProduct" resultType="Product">
<bind name="likename" value="'%' + name + '%'" />
select * from product_ where name like #{likename}
</select>