C-CREATE 创建

c1-普通insert模板

    
              INSERT INTO user        
                 
      
                       username,            
              
             
                 
      
                       #{username,jdbcType=VARCHAR},            
              
         
    

批量插入

      
     
          INSERT INTO TStudent(name,age) VALUES(#{item.name}, #{item.age})  
     
    

防止重复插入

insert into user(username,age)select #{username},#{age} from user where is not exists(select id from user where id = #{id})

R-READ 读取

普通查询模板

        
       
     
    
         d.id,    d.name,    d.user_id,    d.username,  
          select        from user d    WHERE d.user_id= #{userid}  

普通查询模板二

select    *    from user d
    
       ...
    

U-UPDATE 更新

更新模板一

    
      UPDATE User 
       
      
         username=#{username},  
       
      WHERE id=#{id}
    

批量修改

        
     
              update user        
      
                   username=${item.username}        
              where id = ${item.id}    
     
    

D-DELTE 删除

删除模板（不常用 开发中的删除通常为逻辑删除 不做赘述）

    
              DELETE FROM               user         WHERE               id = #{id,jdbcType=NUMERIC}