MyBatis学习3---使用SqlBuilder生成SQL语句

在MyBatis的映射配置文件中写sql语句有时候很方便，但是对于有大量字段的表结构却不太简单，幸好MyBatis提供的有SqlBuilder工具类，可以生成相应的SQL语句，如下例程：

 package com.utils;

 import org.apache.ibatis.jdbc.SqlBuilder;

 public class MyBatisUtils extends SqlBuilder {
     public String selectUserSql() {
         BEGIN();
         SELECT("*");
         FROM("UserDto");
         return SQL();
     }

     public String deleteUserSql() {
         BEGIN();
         DELETE_FROM("UserDto");
         WHERE("username = #{username}");
         return SQL();
     }

     public String insertUserSql() {
         BEGIN();
         INSERT_INTO("UserDto");
         VALUES("username", "#{username}");
         VALUES("password", "#{password}");
         VALUES("address", "#{address}");
         VALUES("age", "#{age}");
         VALUES("sex", "#{sex}");
         return SQL();
     }

     public String updateUserSql() {
         BEGIN();
         UPDATE("UserDto");
         SET("password = #{password}");
         WHERE("username = #{username}");
         return SQL();
     }

     public static void main(String[] args) {
         MyBatisUtils myBatisUtils = new MyBatisUtils();
         System.out.println("查询 = " + myBatisUtils.selectUserSql());
         System.out.println("删除 = " + myBatisUtils.deleteUserSql());
         System.out.println("插入 = " + myBatisUtils.insertUserSql());
         System.out.println("更新 = " + myBatisUtils.updateUserSql());
     }
 }