mysql存储过程详细教程

原文

记录MYSQL存储过程中的关键语法：

下面是存储过程的例子：

mysql> DELIMITER //  mysql> CREATE PROCEDURE proc1(OUT s int) -> BEGIN -> SELECT COUNT(*) INTO s FROM user; -> END -> //  mysql> DELIMITER ;

参数

. IN参数例子

创建:

1. mysql > DELIMITER //  2. mysql > CREATE PROCEDURE demo_in_parameter(IN p_in int) 3. -> BEGIN 4. -> SELECT p_in; 5. -> SET p_in=2; 6. -> SELECT p_in; 7. -> END; 8. -> //  9. mysql > DELIMITER ; 

执行结果:

1. mysql > SET @p_in=1; 2. mysql > CALL demo_in_parameter(@p_in); 3. +------+ 4. | p_in | 5. +------+ 6. | 1 | 7. +------+ 8. 9. +------+ 10.| p_in | 11.+------+ 12.| 2 | 13.+------+ 14. 15.mysql> SELECT @p_in; 16.+-------+ 17.| @p_in | 18.+-------+ 19.| 1 | 20.+-------+ 

以上可以看出，p_in虽然在存储过程中被修改，但并不影响@p_id的值

.OUT参数例子

创建:

1. mysql > DELIMITER //  2. mysql > CREATE PROCEDURE demo_out_parameter(OUT p_out int) 3. -> BEGIN 4. -> SELECT p_out; 5. -> SET p_out=2; 6. -> SELECT p_out; 7. -> END; 8. -> //  9. mysql > DELIMITER ; 

执行结果:

1. mysql > SET @p_out=1; 2. mysql > CALL sp_demo_out_parameter(@p_out); 3. +-------+  4. | p_out | 5. +-------+  6. | NULL | 7. +-------+  8. 9. +-------+  10.| p_out | 11.+-------+  12.| 2 | 13.+-------+  14. 15.mysql> SELECT @p_out; 16.+-------+  17.| p_out | 18.+-------+  19.| 2 | 20.+-------+ 

INOUT参数例子

创建:

1. mysql > DELIMITER //  2. mysql > CREATE PROCEDURE demo_inout_parameter(INOUT p_inout int) 3. -> BEGIN 4. -> SELECT p_inout; 5. -> SET p_inout=2; 6. -> SELECT p_inout; 7. -> END; 8. -> //  9. mysql > DELIMITER ; 

执行结果:

1. mysql > SET @p_inout=1; 2. mysql > CALL demo_inout_parameter(@p_inout) ; 3. +---------+ 4. | p_inout | 5. +---------+ 6. | 1 | 7. +---------+ 8. 9. +---------+ 10.| p_inout | 11.+---------+ 12.| 2 | 13.+---------+ 14. 15.mysql > SELECT @p_inout; 16.+----------+ 17.| @p_inout | 18.+----------+ 19.| 2 | 20.+----------+ 

局部变量

变量定义

1. DECLARE l_int int unsigned default ; 2. DECLARE l_numeric number(8,2) DEFAULT 9.95; 3. DECLARE l_date date DEFAULT '1999-12-31';  4. DECLARE l_datetime datetime DEFAULT '1999-12-31 23:59:59';  5. DECLARE l_varchar varchar(255) DEFAULT 'This will not be padded'; 

变量赋值

SET 变量名 = 表达式值 [,variable_name = expression …]

用户变量

在MySQL客户端使用用户变量

1. mysql > SELECT 'Hello World' into @x; 2. mysql > SELECT @x; 3. +-------------+  4. | @x | 5. +-------------+  6. | Hello World | 7. +-------------+  8. mysql > SET @y='Goodbye Cruel World'; 9. mysql > SELECT @y; 10.+---------------------+  11.| @y | 12.+---------------------+  13.| Goodbye Cruel World | 14.+---------------------+  15. 16.mysql > SET @z=1+2+3; 17.mysql > SELECT @z; 18.+------+  19.| @z | 20.+------+  21.| 6 | 22.+------+ 

在存储过程中使用用户变量

1. mysql > CREATE PROCEDURE GreetWorld( ) SELECT CONCAT(@greeting,' World'); 2. mysql > SET @greeting='Hello'; 3. mysql > CALL GreetWorld( ); 4. +----------------------------+ 5. | CONCAT(@greeting,' World') | 6. +----------------------------+ 7. | Hello World | 8. +----------------------------+ 

在存储过程间传递全局范围的用户变量

1. mysql> CREATE PROCEDURE p1() SET @last_procedure='p1'; 2. mysql> CREATE PROCEDURE p2() SELECT CONCAT('Last procedure was ',@last_procedure); 3. mysql> CALL p1( ); 4. mysql> CALL p2( ); 5. +-----------------------------------------------+ 6. | CONCAT('Last procedure was ',@last_proc | 7. +-----------------------------------------------+ 8. | Last procedure was p1 | 9. +-----------------------------------------------+ 

注释

1. mysql > DELIMITER //  2. mysql > CREATE PROCEDURE proc1 --name存储过程名 3. -> (IN parameter1 INTEGER) 4. -> BEGIN 5. -> DECLARE variable1 CHAR(10); 6. -> IF parameter1 = 17 THEN 7. -> SET variable1 = 'birds'; 8. -> ELSE 9. -> SET variable1 = 'beasts'; 10. -> END IF; 11. -> INSERT INTO table1 VALUES (variable1); 12. -> END 13. -> //  14.mysql > DELIMITER ; 

MySQL存储过程的调用

用call和你过程名以及一个括号，括号里面根据需要，加入参数，参数包括输入参数、输出参数、输入输出参数。具体的调用方法可以参看上面的例子。

MySQL存储过程的查询

MySQL存储过程的修改

MySQL存储过程的删除

MySQL存储过程的控制语句

变量作用域

1. mysql > DELIMITER //  2. mysql > CREATE PROCEDURE proc3() 3. -> begin 4. -> declare x1 varchar(5) default 'outer'; 5. -> begin 6. -> declare x1 varchar(5) default 'inner'; 7. -> select x1; 8. -> end; 9. -> select x1; 10. -> end; 11. -> //  12.mysql > DELIMITER ; 

条件语句

if-then -else语句

1. mysql > DELIMITER //  2. mysql > CREATE PROCEDURE proc2(IN parameter int) 3. -> begin 4. -> declare var int; 5. -> set var=parameter+1; 6. -> if var=0 then 7. -> insert into t values(17); 8. -> end if; 9. -> if parameter=0 then 10. -> update t set s1=s1+1; 11. -> else 12. -> update t set s1=s1+2; 13. -> end if; 14. -> end; 15. -> //  16.mysql > DELIMITER ; 

case语句：

1. mysql > DELIMITER //  2. mysql > CREATE PROCEDURE proc3 (in parameter int) 3. -> begin 4. -> declare var int; 5. -> set var=parameter+1; 6. -> case var 7. -> when 0 then 8. -> insert into t values(17); 9. -> when 1 then 10. -> insert into t values(18); 11. -> else 12. -> insert into t values(19); 13. -> end case; 14. -> end; 15. -> //  16.mysql > DELIMITER ; case when var=0 then insert into t values(30); when var>0 then when var<0 then else end case

循环语句

while ···· end while：

1. mysql > DELIMITER //  2. mysql > CREATE PROCEDURE proc4() 3. -> begin 4. -> declare var int; 5. -> set var=0; 6. -> while var<6 do 7. -> insert into t values(var); 8. -> set var=var+1; 9. -> end while; 10. -> end; 11. -> //  12.mysql > DELIMITER ; while条件 do --循环体 endwhile

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。

1. mysql > DELIMITER //  2. mysql > CREATE PROCEDURE proc5 () 3. -> begin 4. -> declare v int; 5. -> set v=0; 6. -> repeat 7. -> insert into t values(v); 8. -> set v=v+1; 9. -> until v>=5 10. -> end repeat; 11. -> end; 12. -> //  13.mysql > DELIMITER ; repeat --循环体 until循环条件 endrepeat;

loop ·····endloop:

loop循环不需要初始条件，这点和while 循环相似，同时和repeat循环一样不需要结束条件, leave语句的意义是离开循环。

1. mysql > DELIMITER //  2. mysql > CREATE PROCEDURE proc6 () 3. -> begin 4. -> declare v int; 5. -> set v=0; 6. -> LOOP_LABLE:loop 7. -> insert into t values(v); 8. -> set v=v+1; 9. -> if v >=5 then 10. -> leave LOOP_LABLE; 11. -> end if; 12. -> end loop; 13. -> end; 14. -> //  15.mysql > DELIMITER ; 

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。

ITERATE迭代

ITERATE:

1. 通过引用复合语句的标号,来从新开始复合语句 2. mysql > DELIMITER //  3. mysql > CREATE PROCEDURE proc10 () 4. -> begin 5. -> declare v int; 6. -> set v=0; 7. -> LOOP_LABLE:loop 8. -> if v=3 then 9. -> set v=v+1; 10. -> ITERATE LOOP_LABLE; 11. -> end if; 12. -> insert into t values(v); 13. -> set v=v+1; 14. -> if v>=5 then 15. -> leave LOOP_LABLE; 16. -> end if; 17. -> end loop; 18. -> end; 19. -> //  20.mysql > DELIMITER ; 

MySQL存储过程的基本函数

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 1. mysql> select substring('abcd',0,2); 2. +-----------------------+  3. | substring('abcd',0,2) | 4. +-----------------------+  5. | | 6. +-----------------------+  7. 1 row in set (0.00 sec) 8. 9. mysql> select substring('abcd',1,2); 10.+-----------------------+  11.| substring('abcd',1,2) | 12.+-----------------------+  13.| ab | 14.+-----------------------+  15.1 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

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 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 1. mysql> select round(1.23); 2. +-------------+  3. | round(1.23) | 4. +-------------+  5. | 1 | 6. +-------------+  7. 1 row in set (0.00 sec) 8. 9. mysql> select round(1.56); 10.+-------------+  11.| round(1.56) | 12.+-------------+  13.| 2 | 14.+-------------+  15.1 row in set (0.00 sec) (2)可以设定小数位数，返回浮点型数据 1. mysql> select round(1.567,2); 2. +----------------+  3. | round(1.567,2) | 4. +----------------+  5. | 1.57 | 6. +----------------+  7. 1 row in set (0.00 sec) SIGN (number2 ) //

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

MySql分页存储过程

MySql测试版本：5.0.41-community-nt

DROP PROCEDURE IF EXISTS pr_pager; CREATE PROCEDURE pr_pager( IN p_table_name VARCHAR(1024), IN p_fields VARCHAR(1024), IN p_page_size INT, IN p_page_now INT, IN p_order_string VARCHAR(128), IN p_where_string VARCHAR(1024), OUT p_out_rows INT ) NOT DETERMINISTIC SQL SECURITY DEFINER COMMENT '分页存储过程' BEGIN DECLARE m_begin_row INT DEFAULT 0; DECLARE m_limit_string CHAR(64); SET m_begin_row = (p_page_now - 1) * p_page_size; SET m_limit_string = CONCAT(' LIMIT ', m_begin_row, ', ', p_page_size); SET @COUNT_STRING = CONCAT('SELECT COUNT(*) INTO @ROWS_TOTAL FROM ', p_table_name, ' ', p_where_string); SET @MAIN_STRING = CONCAT('SELECT ', p_fields, ' FROM ', p_table_name, ' ', p_where_string, ' ', p_order_string,m_limit_string); PREPARE count_stmt FROM @COUNT_STRING; EXECUTE count_stmt; DEALLOCATE PREPARE count_stmt; SET p_out_rows = @ROWS_TOTAL; PREPARE main_stmt FROM @MAIN_STRING; EXECUTE main_stmt; DEALLOCATE PREPARE main_stmt; END;

调用

mysql> call pr_pager("t","var",3,3,"","",@result); mysql> call pr_pager("t","var",3,2,"","",@result);