1.<select> 

2.<insert>

3.<update>

4.<delete>

5.<foreach>

  

   

    

     

    
    

     

      <foreach collection="barcodeManageBo" item="object" separator=","
     
    
   

    

     

    
    

     

      			open="(" close=")">
     
    
   

    

     

    
    

     

      			#{object.id}
     
    
   

    

     

    
    

     

      </foreach>
     
    
  
 

open；以什么开始 

close：以什么结束

separator：分隔符

collection：list名称

item：index名称

6.<sql>

  

   

    

     

    
    

     

      <sql id="sqlvalues">
     
    
   

    

     

    
    

     
		<if test="code!=null or code !=''">#{code},</if>
     
    
   

    

     

    
    

     
		<if test="itemname !=null or itemname !=''">#{itemname},</if>
     
    
   

    

     

    
    

     
		<if test="criteria !=null or criteria !=''">#{criteria},</if>
     
    
   

    

     

    
    

     

      </sql>
     
    
  
 

7.<include>>

<include refid="sqlvalues"></include>
 

引用sql标签

8.<set>

  

   

    

     

    
    

     

      <set>
     
    
   

    

     

    
    

     

        <if test="typeName != null and typeName != ''">
     
    
   

    

     

    
    

     

              typeName ={typeName}, 
     
    
   

    

     

    
    

     

        </if>
     
    
   

    

     

    
    

     

        <if test="sort != null and sort != ''">sort = #{sort},</if>
     
    
   

    

     

    
    

     

      </set>
     
    
  
 

在set时候省略最后一个符号

9.trim标签

  

   

    

     

    
    

     

      <trim suffix="" suffixOverrides=",">
     
    
   

    

     

    
    

     
				<if test="code!=null"> code = #{code},</if>
     
    
   

    

     

    
    

     
				<if test="itemname !=null"> itemname =#{itemname},</if>
     
    
   

    

     

    
    

     
				<if test="criteria !=null "> criteria =#{criteria},</if>
     
    
   

    

     

    
    

     

      </trim>
     
    
  
 

prefix：前缀覆盖并增加其内容

suffix：后缀覆盖并增加其内容

prefixOverrides：前缀判断的条件

suffixOverrides：后缀判断的条件

将,变成空格

10.<if>标签

11.<choose >

  

   

    

     

    
    

     

      <choose>
     
    
   

    

     

    
    

     
            <when test="title != null">
     
    
   

    

     

    
    

     

                      and title = #{title}
     
    
   

    

     

    
    

     
            </when>
     
    
   

    

     

    
    

     
            <when test="content != null">
     
    
   

    

     

    
    

     

                      and content = #{content}
     
    
   

    

     

    
    

     
            </when>
     
    
   

    

     

    
    

     
            <otherwise>
     
    
   

    

     

    
    

     

                      and owner = "owner1"
     
    
   

    

     

    
    

     
            </otherwise>
     
    
   

    

     

    
    

     

      </choose>
     
    
  
 

12.<resultMap>

  

   

    

     

    
    

     

      <resultMap id="getStudentRM" type="EStudnet">
     
    
   

    

     

    
    

     
  <id property="id" column="ID"/>
     
    
   

    

     

    
    

     
  <result property="studentName" column="Name"/>
     
    
   

    

     

    
    

     
  <result property="studentAge" column="Age"/>
     
    
   

    

     

    
    

     

      </resultMap>
     
    
   

    

     

    
    

     

      <select id="getStudent" resultMap="getStudentRM">
     
    
   

    

     

    
    

     

        SELECT ID, Name, Age
     
    
   

    

     

    
    

     

          FROM TStudent
     
    
   

    

     

    
    

     

      </select>
     
    
  
 

其他sql小技巧

时间转为String

DATE_FORMAT(scanDate,'%Y-%m-%d %H:%i') as scanDate,

文章来源: baocl.blog.csdn.net，作者：小黄鸡1992，版权归原作者所有，如需转载，请联系作者。

原文链接：baocl.blog.csdn.net/article/details/83345691