一.存储过程和函数的区别

函数调用有返回值

存储过程调用用call语句，函数调用直接饮用函数名+参数

IN，OUT，INOUT

只适用于存储过程，对函数而言所有参数默认都是输入参数

IN用于把数值传入到存储过程中

OUT用于输出参数将数值传递给调用者

INOUT输入输出参数把数据传入到存储过程，在存储过程中修改后再传递给调用者

二.存储过程实践

功能:格式化数据

DELIMITER //

CREATE PROCEDURE sieAttendanceService.checkData(IN myId BIGINT, OUT spaceId BIGINT)

SQL SECURITY INVOKER

BEGIN

DECLARE space_num INT DEFAULT 0;

DECLARE temp VARCHAR(50);

DECLARE num_index INT DEFAULT 0;

select count(*) from sie_attendance_external_t t where t.on_time='' and t.off_time='' and t.id > myId into space_num;

while num_index < space_num do

set num_index = num_index + 1;

select id from sie_attendance_external_t t where t.on_time='' and t.off_time='' and t.id > myId into spaceId;

end while;

/*更新供应商编号*/

update sie_attendance_external_t t

set t.company_code = '032128'

where id > myId;

/*去掉空格*/

update sie_attendance_external_t t

set t.staff_name = trim(t.staff_name),

t.staff_id_no = trim(t.staff_id_no),

t.swipe_date = trim(t.swipe_date),

t.on_time = trim(t.on_time),

t.off_time = trim(t.off_time)

where t.id > myId;

/*将？替换成空*/

update sie_attendance_external_t t

set t.staff_name = replace(t.staff_name,CHAR(120),''),

t.staff_id_no = replace(t.staff_id_no,CHAR(120),''),

t.swipe_date = replace(t.swipe_date,CHAR(120),''),

t.on_time = replace(t.on_time,CHAR(120),''),

t.off_time = replace(t.off_time,CHAR(120),'')

where t.id > myId;

/*将.替换成：*/

update sie_attendance_external_t t

set t.staff_name = replace(t.staff_name,CHAR(190),CHAR(16)),

t.staff_id_no = replace(t.staff_id_no,CHAR(190),CHAR(16)),

t.swipe_date = replace(t.swipe_date,CHAR(190),CHAR(16)),

t.on_time = replace(t.on_time,CHAR(190),CHAR(16)),

t.off_time = replace(t.off_time,CHAR(190),CHAR(16))

where t.id > myId;

/*去掉回车和换行*/

update sie_attendance_external_t t

set t.staff_name = REPLACE(REPLACE(t.staff_name, CHAR(10), ''), CHAR(13),''),

t.staff_id_no = REPLACE(REPLACE(t.staff_id_no, CHAR(10), ''), CHAR(13),''),

t.swipe_date = REPLACE(REPLACE(t.swipe_date, CHAR(10), ''), CHAR(13),''),

t.on_time = REPLACE(REPLACE(t.on_time, CHAR(10), ''), CHAR(13),''),

t.off_time = REPLACE(REPLACE(t.off_time, CHAR(10), ''), CHAR(13),'')

where t.id > myId;

/*更新上班时间格式*/

update sie_attendance_external_t t

set t.on_time = (

select case when length(tt.on_time)=7

then concat('0',tt.on_time)

else

tt.on_time

end

from (select * from sie_attendance_external_t) tt where t.id = tt.id)

where id > myId;

/*更新下班时间格式*/

update sie_attendance_external_t t

set t.off_time = (

select case when length(tt.off_time)=7

then concat('0',tt.off_time)

else

tt.off_time

end

from (select * from sie_attendance_external_t) tt where t.id = tt.id)

where id > myId;

END

//

函数实践

作用： 从不规则的数据中截取时间戳。

DELIMITER $$

create function getnum(param varchar(50))

returns varchar(50)

begin

DECLARE postion INT;

DECLARE len INT;

DECLARE str varchar(50) DEFAULT param;

DECLARE tmp varchar(50) DEFAULT '';

set postion = (select InStr (param,'_')-1);

/*判断是否存在下划线*/

if postion <> -1 then

set str = (select left(param,postion));

end if;

/*开始循环判断*/

set len = char_length(str);

lop:begin

while len > 0 do

if(ascii(mid(str,len,1))>47 and ascii(mid(str,len,1))<58) then

set tmp = concat(tmp,mid(str,len,1));

else

/*如果不是数字，直接返回*/

LEAVE lop;

END IF;

SET len = len - 1;

END WHILE;

end lop;

/*返回结果集*/

return REVERSE(tmp);

end $$

总结：存储过程的使用需用call 关键字调用，

函数直接select中使用，直接拿到返回值。