虽然MySQL的存储过程，一般情况下，是不会使用到的，但是在一些特殊场景中，还是有需求的。最近遇到一个sql server向mysql迁移的项目，有一些sql server的存储过程需要向mysql迁移。所以进行复习了一下。下面是一些存储过程的例子。
1. 例子1
DELIMITER //DROP PROCEDURE IF EXISTS loginandreg //CREATE PROCEDURE loginandreg( OUT userId BIGINT, IN user_Pwd VARCHAR(32), IN user_MobileCode VARCHAR(16), IN user_RegIP VARCHAR(16))BEGINDECLARE cnt BIGINT DEFAULT 0;DECLARE cnt2 BIGINT DEFAULT 0;DECLARE outid BIGINT DEFAULT -1;SELECT COUNT(*) INTO cnt FROM Users u WHERE u.user_MobileCode=user_MobileCode;IF cnt > 0 THEN SELECT COUNT(*) INTO cnt2 FROM Users u WHERE u.user_MobileCode=user_MobileCode AND u.user_Pwd=user_Pwd; IF cnt2 > 0 THEN SELECT u.userId INTO outid FROM Users u WHERE u.user_MobileCode=user_MobileCode AND u.user_Pwd=user_Pwd LIMIT 1; ELSE SELECT -1 INTO outid; END IF; SELECT outid INTO userId;ELSE INSERT INTO Users(user_Pwd,user_MobileCode,user_Visibility,user_Level,user_RegTime,user_RegIP,
user_Collecter,user_Collected) VALUES (user_Pwd,user_MobileCode,6,6,NOW(),user_RegIP,0,0); SET userId=LAST_INSERT_ID(); SELECT userId;END IF;END //DELIMITER ;
知识点：
1）参数分为 in, out 类型，即输入类型和输出类型；
2）select xx into varible from table where ... 句式：
SELECT COUNT(*) INTO cnt FROM Users u WHERE u.user_MobileCode=user_MobileCode;
3）if cnt > 0 then ... elseif cnt =0 then ... else ... end if;
if 语句注意带有 then 关键字和 end if 结束关键字。
4）获取 insert 语句的主键：set userId=last_insert_id(); select userId;
select last_insert_id() into userId; 也是可以的。
5）mysql客户端 如何调用该存储过程：
CALL loginandreg(@userId,'123456','18357xxx7','127.0.0.1');SELECT @userId;最后的 select @userId 就是存储过程的 out 类型参数返回的结果。
6) 上面的例子，还可以使用 if exists ( select from ...) 语句和 FOUND_ROWS() 函数 来优化一下：
DELIMITER //DROP PROCEDURE IF EXISTS loginandreg //CREATE PROCEDURE loginandreg( OUT userId BIGINT, IN user_Pwd VARCHAR(32), IN user_MobileCode VARCHAR(16), IN user_RegIP VARCHAR(16))BEGINIF EXISTS(SELECT * FROM Users u WHERE u.user_MobileCode=user_MobileCode) THEN SELECT u.userId INTO userId FROM Users u WHERE u.user_MobileCode=user_MobileCode AND u.user_Pwd=user_Pwd; IF FOUND_ROWS() < 1 THEN SELECT -1 INTO userId; END IF;ELSE INSERT INTO Users(user_Pwd,user_MobileCode,user_Visibility,user_Level,user_RegTime,user_RegIP,
user_Collecter,user_Collected) VALUES (user_Pwd,user_MobileCode,6,6,NOW(),user_RegIP,0,0); SELECT LAST_INSERT_ID() INTO userId;END IF;END //DELIMITER ;
2. 例子2
DELIMITER //DROP PROCEDURE IF EXISTS mingRenTangJiangLi //CREATE PROCEDURE mingRenTangJiangLi()BEGINDECLARE total_level,role_id,ming_ren_level,ming_ren_type, fuben_times,tiaozhan_times,duobei_shijian,no_more_data INT DEFAULT 0;DECLARE my_cursor CURSOR FOR SELECT playerRoleId,`level`,type from mingrentang;DECLARE CONTINUE HANDLER FOR NOT FOUND SET no_more_data = 1;OPEN my_cursor;FETCH my_cursor INTO role_id,ming_ren_level,ming_ren_type;REPEATset total_level = ming_ren_level + 10 * (ming_ren_type-1);set fuben_times = total_level / 2;set tiaozhan_times = total_level /3;set duobei_shijian = 10 * total_level;select total_level,fuben_times,tiaozhan_times,duobei_shijian;update player_role set hufu=hufu+1000,paihangbangNumber=paihangbangNumber+tiaozhan_times, duobeiShiJian=duobeiShiJian+duobei_shijian,fubenTimes=fubenTimes+fuben_times;FETCH my_cursor INTO role_id,ming_ren_level,ming_ren_type;UNTIL no_more_data = 1END REPEAT;CLOSE my_cursor;END //DELIMITER ;
知识点：
1）该例子演示了游标的用法：
DECLARE my_cursor CURSOR FOR SELECT playerRoleId,`level`,type from mingrentang;DECLARE CONTINUE HANDLER FOR NOT FOUND SET no_more_data = 1;定义了游标语句，也说明了游标循环结束时设置的标志：SET no_more_data = 1;
OPEN my_cursor;FETCH my_cursor INTO role_id,ming_ren_level,ming_ren_type;打开游标，从游标中获取值。
REPEAT
......
FETCH my_cursor INTO role_id,ming_ren_level,ming_ren_type;UNTIL no_more_data = 1END REPEAT;repeat 循环 直到 no_more_data = 1： UNTIL no_more_data = 1，然后结束循环 END REPEAT;
最后关闭游标 close my_cursor;
因为上面在定义游标时，指明了，没有数据时设置了 no_more_data = 1，所以这里使用 UNTIL no_more_data = 1 来退出repeat
2）判断相等是使用 = ，而不是 == ，赋值操作是使用 set var=xxx; ：set fuben_times = total_level / 2;
3）循环： repeat ... until ... end repeat;
3. Java 如何调用存储过程
1）hibernate调用存储过程：
/* * 调用无参数的存储过程，传入存储过程名字 */ public int callProcedure(final String procedureName) { int count = (Integer)this.getHibernateTemplate().execute( new HibernateCallback(){ public Object doInHibernate(Session session) throws HibernateException, SQLException { String procedureSql = "{call "+ procedureName +"()}"; Query query = session.createSQLQuery(procedureSql); Integer num = query.executeUpdate(); return num; } }); return count; }
2）ibatis 调用mysql 存储过程：
@Override public Long loginAndRegByProcedure(String user_Pwd, String user_MobileCode, String user_RegIP){ Long userId = null; HashMap<String,Object> paramMap = new HashMap<String,Object>(); paramMap.put("userId", userId); paramMap.put("user_Pwd", user_Pwd); paramMap.put("user_MobileCode", user_MobileCode); paramMap.put("user_RegIP", user_RegIP); this.getSqlMapClientTemplate().queryForObject("Users.loginAndRegByProcedure", paramMap); return (Long)paramMap.get("userId"); }
对应的xml 文件配置：
<parameterMap id="pro_pram_Map" class="java.util.Map"> <parameter property="userId" javaType="java.lang.Long" jdbcType="BIGINT" mode="OUT"/> <parameter property="user_Pwd" javaType="java.lang.String" jdbcType="VARCHAR" mode="IN"/> <parameter property="user_MobileCode" javaType="java.lang.String" jdbcType="VARCHAR" mode="IN"/> <parameter property="user_RegIP" javaType="java.lang.String" jdbcType="VARCHAR" mode="IN"/> </parameterMap> <procedure id="loginAndRegByProcedure" parameterMap="pro_pram_Map"> {call loginandreg(?, ?, ?, ?)} </procedure>
存储过程的参数的类型，是在xml文件中说明的。
3) JDBC 调用mysql 存储过程：
public Long loginAndRegByProcedure2(String user_Pwd, String user_MobileCode, String user_RegIP){ Connection conn = DbUtil.getConnection(); CallableStatement cstmt = conn.prepareCall("{call loginandreg(?, ?, ?, ?)}"); cstmt.setString(2, user_Pwd); cstmt.setString(3, user_MobileCode); cstmt.setString(4, user_RegIP); cstmt.registerOutParameter(1, java.sql.Types.BIGINT); cstmt.execute(); return cstmt.getLong(1); }
输入参数：cstmt.setString(2, user_Pwd);
输出参数：cstmt.registerOutParameter(1, java.sql.Types.BIGINT);
4）mybatis 调用mysql存储过程：
mapper 接口
public interface UserMapper { Long loginAndRegByProcedure(Map<String, Object> param);
xml 配置文件
<select id="loginAndRegByProcedure" parameterType="java.util.Map" statementType="CALLABLE" resultType="long"> {call loginandreg( #{userId,jdbcType=BIGINT,mode=OUT}, #{user_Pwd,jdbcType=VARCHAR,mode=IN}, #{user_MobileCode,jdbcType=VARCHAR,mode=IN}, #{user_RegIP,jdbcType=VARCHAR,mode=IN} ) } </select>
注意： statementType="CALLABLE" resultType="long" 和 mode=OUT
service 层调用mapper接口:
Long userId = null; HashMap<String,Object> paramMap = new HashMap<String,Object>(); paramMap.put("userId", userId); paramMap.put("user_Pwd", user_Pwd); paramMap.put("user_MobileCode", user_MobileCode); paramMap.put("user_RegIP", user_RegIP);
userId=userMapper.loginAndRegByProcedure(map);