一口气弄完了！
一、条件语句if-then-else:
create procedure demo_1(in param int)begindeclare var int;set var=param-1;if var=0 theninsert into userinfo(name) values('demo');elseinsert into userinfo(name) values('demo');end if;if param=0 thenupdate userinfo set age=param where name='demo';elseupdate userinfo set age=1 where name='demo';end if;end// 仅作语法参考并无实际意义。
二、case语句：
create procedure demo_2(in param int)begincase paramwhen 0 theninsert into userinfo(name) values('demo_0');when 1 theninsert into userinfo(name) values('demo_1');elseinsert into userinfo(name) values('demo_default');end case;end// 调用的话可以：
call demo_2(1)//
三、循环语句while-endwhile
create procedure demo_3(in param int)beginwhile param<10 doinsert into userinfo(name) values('demo');set param=param+1;end while;end// 四、repeat...end repeat：
它在执行操作后检查结果，而while则是执行前进行检查。相当于do...while
create procedure demo_4(in param int)beginrepeatinsert into userinfo(name) values('demo');set param=param+1;until param>10end repeat;end// until表示满足后边的条件才继续循环
五、loop...end loop语句
create procedure demo_5(in param int)begindemo_5:loopinsert into userinfo(name) values('demo_5');set param=param+1;if param>10 thenleave demo_5;end if;end loop;end// call demo_5(7)则输入插入4个demo_5。
六、LABLES标号：
标号可以用在begin repeat while 或者loop 语句前，语句标号只能在合法的语句前面使用。可以跳出循环，使运行指令达到复合语句的最后一步。
七、ITERATE:
通过引用复合语句的标号,来从新开始复合语句
create procedure demo_6(in param int)begindeclare v int;set v=0;LOOP_LABLE:loopif v=3 thenset v=v+1;ITERATE LOOP_LABLE;end if;insert into userinfo(name) values('demo_6');set v=v+1;if v>=5 thenleave LOOP_LABLE;end if;end loop;end//
引：MySQL存储过程的基本函数
1、操作字符串类
CHARSET(str) //返回字串字符集 CONCAT (string2 [,... ]) //连接字串 INSTR (string ,substring ) //返回substring首次在string中出现的位置,不存在返回0 LCASE (string2 ) //转换成小写 LEFT (string2 ,length ) //从string2中的左边起取length个字符 LENGTH (string ) //string长度 LOAD_FILE (file_name ) //从文件读取内容 LOCATE (substring , string [,start_position ] ) 同INSTR,但可指定开始位置 LPAD (string2 ,length ,pad ) //重复用pad加在string开头,直到字串长度为length LTRIM (string2 ) //去除前端空格 REPEAT (string2 ,count ) //重复count次 REPLACE (str ,search_str ,replace_str ) //在str中用replace_str替换search_str RPAD (string2 ,length ,pad) //在str后用pad补充,直到长度为length RTRIM (string2 ) //去除后端空格 STRCMP (string1 ,string2 ) //逐字符比较两字串大小, SUBSTRING (str , position [,length ]) //从str的position开始,取length个字符,注：mysql中处理字符串时，默认第一个字符下标为1，即参数position必须大于等于1
- mysql> select substring('abcd',0,2);
- +-----------------------+
- | substring('abcd',0,2) |
- +-----------------------+
- | |
- +-----------------------+
- 1 row in set (0.00 sec)
- mysql> select substring('abcd',1,2);
- +-----------------------+
- | substring('abcd',1,2) |
- +-----------------------+
- | ab |
- +-----------------------+
- 1 row in set (0.02 sec)
TRIM([[BOTH|LEADING|TRAILING] [padding] FROM]string2) //去除指定位置的指定字符 UCASE (string2 ) //转换成大写 RIGHT(string2,length) //取string2最后length个字符 SPACE(count) //生成count个空格
2、数学类
ABS (number2 ) //绝对值 BIN (decimal_number ) //十进制转二进制 CEILING (number2 ) //向上取整 CONV(number2,from_base,to_base) //进制转换 FLOOR (number2 ) //向下取整 FORMAT (number,decimal_places ) //保留小数位数 HEX (DecimalNumber ) //转十六进制注：HEX()中可传入字符串，则返回其ASC-11码，如HEX('DEF')返回4142143也可以传入十进制整数，返回其十六进制编码，如HEX(25)返回19 LEAST (number , number2 [,..]) //求最小值 MOD (numerator ,denominator ) //求余 POWER (number ,power ) //求指数 RAND([seed]) //随机数 ROUND (number [,decimals ]) //四舍五入,decimals为小数位数]
注：返回类型并非均为整数，如： (1)默认变为整形值
- mysql> select round(1.23);
- +-------------+
- | round(1.23) |
- +-------------+
- | 1 |
- +-------------+
- 1 row in set (0.00 sec)
- mysql> select round(1.56);
- +-------------+
- | round(1.56) |
- +-------------+
- | 2 |
- +-------------+
- 1 row in set (0.00 sec)
(2)可以设定小数位数，返回浮点型数据
- mysql> select round(1.567,2);
- +----------------+
- | round(1.567,2) |
- +----------------+
- | 1.57 |
- +----------------+
- 1 row in set (0.00 sec)
SIGN (number2 ) //
3、日期时间类
ADDTIME (date2 ,time_interval ) //将time_interval加到date2 CONVERT_TZ (datetime2 ,fromTZ ,toTZ ) //转换时区 CURRENT_DATE ( ) //当前日期 CURRENT_TIME ( ) //当前时间 CURRENT_TIMESTAMP ( ) //当前时间戳 DATE (datetime ) //返回datetime的日期部分 DATE_ADD (date2 , INTERVAL d_value d_type ) //在date2中加上日期或时间 DATE_FORMAT (datetime ,FormatCodes ) //使用formatcodes格式显示datetime DATE_SUB (date2 , INTERVAL d_value d_type ) //在date2上减去一个时间 DATEDIFF (date1 ,date2 ) //两个日期差 DAY (date ) //返回日期的天 DAYNAME (date ) //英文星期 DAYOFWEEK (date ) //星期(1-7) ,1为星期天 DAYOFYEAR (date ) //一年中的第几天 EXTRACT (interval_name FROM date ) //从date中提取日期的指定部分 MAKEDATE (year ,day ) //给出年及年中的第几天,生成日期串 MAKETIME (hour ,minute ,second ) //生成时间串 MONTHNAME (date ) //英文月份名 NOW ( ) //当前时间 SEC_TO_TIME (seconds ) //秒数转成时间 STR_TO_DATE (string ,format ) //字串转成时间,以format格式显示 TIMEDIFF (datetime1 ,datetime2 ) //两个时间差 TIME_TO_SEC (time ) //时间转秒数] WEEK (date_time [,start_of_week ]) //第几周 YEAR (datetime ) //年份 DAYOFMONTH(datetime) //月的第几天 HOUR(datetime) //小时 LAST_DAY(date) //date的月的最后日期 MICROSECOND(datetime) //微秒 MONTH(datetime) //月 MINUTE(datetime) //分返回符号,正负或0 SQRT(number2) //开平方