Mysql存储过程知识,案例:

create procedure delete_setting(in p_settingid integer)
begin
delete
from setting
where settingid=p_settingid;
end select `name` from mysql.proc where db = 'your_db_name' and `type` = 'PROCEDURE' show procedure status; show create procedure proc_name; show create function func_name; 局部变量 create procedure test3(out number1 integer)
begin
declare number2 integer default 100;
set number1=number2;
end call test(@number) select @number# 默认值为标量子查询 create procedure test2(out ta integer)
begin
declare tt integer default (select count(*) from `setting`);
set ta=tt;
end 流程控制 IF create procedure getMax(in p1 integer,in p2 integer,out p3 integer)
begin
if p1>p2 then
set p3 = p1;
elseif p1<p2 then
set p3 = p2;
else
set p3=0;
end if;
end fibonnaci create procedure fibonnaci(inout n1 integer,inout n2 integer,inout n3 integer)
begin
set n3=n1+n2;
if n3>1000 then
set n3 = n3-1000;
end if;
set n1=n2;
set n2=n3;
end create procedure largest(out t char(30))
begin
if (select count(*) from product)>(select count(*) from productcategory) then
set t="product";
elseif (select count(*) from product)<(select count(*) from productcategory) then
set t="productcategory";
else
set t = "equal";
end if;
end create procedure small_exit(out p1 integer,out p2 integer)
begin
set p1 = 1;
set p2 = 2;
block1:begin
leave block1;
set p2 = 3;
end;
set p1=4;
end WHILE 计算两个相差的年月日 create procedure age(
in start_date date,
in end_date date,
out years integer,
out monthes integer,
out days integer
)
begin
declare next_date,previous_date date; set years = 0;
set previous_date=start_date;
set next_date =start_date+interval 1 year;
while next_date<end_date do
set years = years+1;
set previous_date = next_date;
set next_date = next_date+ interval 1 year;
end while; set monthes = 0;
set next_date = previous_date + interval 1 month;
while next_date<end_date do
set monthes = monthes +1;
set previous_date=next_date;
set next_date = previous_date+interval 1 month;
end while;
end ————————————————————————
调用存储过程
建表
create table players_with_parents
(playerno integer not null primary key,
father_playerno integer,
mother_playerno integer); alter table players_with_parents add constraint fk_1
foreign key (father_playerno) references player_with_parents (playerno); alter table players_with_parents add
foreign key (mother_playerno) references player_with_parents(playerno); 增加外键约束; insert into players_with_parents values(9,null,null),(8,null,null),(7,null,null),(6,null,null),(5,null,null)
,(4,8,9),(3,6,7),(2,4,5),(1,2,3) create procedure total_number_of_parents(in_playerno integer,inout number integer)
begin
declare v_father,v_mother integer;
set v_father =
(select father_playerno from players_with_parents where playerno=in_playerno); set v_mother =
(select mother_playerno from players_with_parents where playerno=in_playerno); if v_father is not null then
call total_number_of_parents(v_father,number);
set number = number+1;
end if; if v_mother is not null then
call total_number_of_parents(v_mother,number);
set number = number+1;
end if;
end
set @num=0;
set max_sp_recursion_depth=100;
call total_number_of_parents(4,@num);
select @num; select into create procedure total_setting(out p1 integer)
begin
select count(*) into p1 from `setting`;
end create procedure get_setting(out v_name varchar(60),out v_value varchar(60))
begin
select `name`,`value` into v_name,v_value from setting limit 0,1;
end create procedure showErr(out p integer)
begin
set p=1;
insert into `setting` (`settingid`,`name`)values(12,'vname');
set p=2;
end create procedure showErr(out p integer,out error integer)
begin
declare continue handler for sqlstat '23000'
set error = '200000';
declare continue handler for sqlstat '23001';
set error = '200001';
set error = '000000';
set p=1;
insert into `setting` (`settingid`,`name`)values(12,'vname');
set p=2;
end declare continue handler for 1062 set error='23000';
declare continue handler for 1136 set error='21S01'; 01 SQLWARING
02 NOT FOUND
SQLEXCEPTION 01,02以外的 create procedure addDate(out error char(5))
begin
declare continue handler for sqlstate '23000' set error='23000';
declare continue handler for sqlstate '21S01' set error='21S01';
set error='00000';
insert into `setting` values(15,'test','testValue',10);
end declare non_unique condition for sqlstate '23000';
ddeclare continue handler for non_unique set error='23000'; 同一块中,相同的错误,不能有两个或多个处理程序; 带有游标的存储过程
declare c_players cursor for select playerno from players; create procedure number_of_players(out number integer)
begin
declare a_playerno integer;
declare found boolean default true;
declare c_players cursor for select playerno from players;
declare continue handler for not found set found=false;
set number=0;
open c_players;
fetch c_players into a_playerno;
while found do
set number =number+1;
fetch c_players into a_playerno;
end while;
close c_players;
end create procedure number_of_setting(out number integer)
begin
declare a_settingid integer;
declare found boolean default true;
declare c_settingids cursor for select settingid from setting;
declare continue handler for not found set found=false;
set number=0;
open c_settingids;
fetch c_settingids into a_settingid;
while found do
set number=number+1;
fetch c_settingids into a_settingid;
end while;
close c_settingids;
end create procedure delete_older_than_30()
begin
declare v_age,v_playerno,v_years,v_months,v_days integer;
declare v_birth_date date;
declare found boolean default true;
declare c_players cursor for
select playerno,birth_date from players;
declare continue handler for not found set found=false;
open c_players;
fetch c_players into v_playerno,v_birth_date;
while found do
call age(v_birth_date,now(),v_years,v_months,v_days);
if v_years>30 then
delete from penalties where playerno=v_playerno;
end if;
fetch c_players into v_playno,v_birth_date;
end while;
close c_players;
end commit,rollback,start transaction; create function test(t1 integer,t2 integer) returns integer
begin
return t1+t2;
end

查询数据库中的存储过程

方法一:

select `name` from mysql.proc where db = 'your_db_name' and `type` = 'PROCEDURE'

方法二:

show procedure status;

查看存储过程或函数的创建代码

show create procedure proc_name;
show create function func_name;

查询数据库中的存储过程和函数

方法一:

select `name` from mysql.proc where db = 'your_db_name' and `type` = 'PROCEDURE'   //存储过程
       select `name` from mysql.proc where db = 'your_db_name' and `type` = 'FUNCTION'   //函数

方法二:

show procedure status; //存储过程

show function status;     //函数

查看存储过程或函数的创建代码

show create procedure proc_name;
show create function func_name;

查看视图

SELECT * from information_schema.VIEWS   //视图

SELECT * from information_schema.TABLES   //表

查看触发器

方法一:
语法:SHOW TRIGGERS [FROM db_name] [LIKE expr]
实例:SHOW TRIGGERS\G     //触发器

方法二:
对INFORMATION_SCHEMA数据库中的TRIGGERS表查询
mysql>SELECT * FROM triggers T WHERE trigger_name=”mytrigger” \G

在存儲過程中使用 表名做变量传递:

PREPARE stmt_name FROM preparable_stmt;
EXECUTE stmt_name [USING @var_name [, @var_name] ...];
{DEALLOCATE | DROP} PREPARE stmt_name;

下面是示例:

DROP PROCEDURE IF EXISTS `newtable`;
CREATE PROCEDURE `newtable`(IN tname varchar(64))
BEGIN
SET @sqlcmd = CONCAT('CREATE TABLE ', tname, ' (id int NOT NULL AUTO_INCREMENT, name varchar(64) DEFAULT NULL, PRIMARY KEY (`id`))');
PREPARE stmt FROM @sqlcmd;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
END;
call newtable('abc');

 再来一个示例:

create procedure ate(in t char(30))
begin
set @s=concat("alter table ",t," engine=innodb");
prepare stmt from @s;
execute stmt;
deallocate prepare stmt;
end
call ate('deal')#

  

看下面的示例:

mysql> SET @s = 'SELECT SQRT(POW(?,2) + POW(?,2)) AS hypotenuse';
mysql> PREPARE stmt2 FROM @s;
mysql> SET @a = 6;
mysql> SET @b = 8;
mysql> EXECUTE stmt2 USING @a, @b;
+------------+
| hypotenuse |
+------------+
| 10 |
+------------+
mysql> DEALLOCATE PREPARE stmt2;

在sql中替换变量;

如果你的MySQL 版本是 5.0.7 或者更高的,你还可以在 LIMIT 子句中使用它,示例如下:

mysql> SET @a=1;mysql> PREPARE STMT FROM "SELECT * FROM tbl LIMIT ?";
mysql> EXECUTE STMT USING @a;
mysql> SET @skip=1; SET @numrows=5;
mysql> PREPARE STMT FROM "SELECT * FROM tbl LIMIT ?, ?";
mysql> EXECUTE STMT USING @skip, @numrows;

使用 PREPARE 的几个注意点:
A:PREPARE stmt_name FROM preparable_stmt;预定义一个语句,并将它赋给 stmt_name ,tmt_name 是不区分大小写的。
B: 即使 preparable_stmt 语句中的 ? 所代表的是一个字符串,你也不需要将 ? 用引号包含起来。
C: 如果新的 PREPARE 语句使用了一个已存在的 stmt_name ,那么原有的将被立即释放! 即使这个新的 PREPARE 语句因为错误而不能被正确执行。
D: PREPARE stmt_name 的作用域是当前客户端连接会话可见。
E: 要释放一个预定义语句的资源,可以使用 DEALLOCATE PREPARE 句法。
F: EXECUTE stmt_name 句法中,如果 stmt_name 不存在,将会引发一个错误。
G: 如果在终止客户端连接会话时,没有显式地调用 DEALLOCATE PREPARE 句法释放资源,服务器端会自己动释放它。
H: 在预定义语句中,CREATE TABLE, DELETE, DO, INSERT, REPLACE, SELECT, SET, UPDATE, 和大部分的 SHOW 句法被支持。
I: PREPARE 语句不可以用于存储过程,自定义函数!但从 MySQL 5.0.13 开始,它可以被用于存储过程,仍不支持在函数中使用!

了解了PREPARE的用法,再用变量做表名就很容易了。不过在实际操作过程中还发现其他一些问题,比如变量定义,declare变量和set @var=value变量的用法以及参数传入的变量。

测试后发现,set @var=value这样定义的变量直接写在字符串中就会被当作变量转换,declare的变量和参数传入的变量则必须用CONCAT来连接。具体的原理没有研究。

EXECUTE stmt USING @a;这样的语句USING后面的变量也只能用set @var=value这种,declare和参数传入的变量不行。

另外php调用mysql存储过程的时候也碰到很多问题,总是出现PROCEDURE p can't return a result set in the given context这样的问题。

mysql存储过程基本函数

一.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

二.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 ) //返回符号,正负或0
SQRT(number2) //开平方

三.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
附:可用在INTERVAL中的类型
DAY ,DAY_HOUR ,DAY_MINUTE ,DAY_SECOND ,HOUR ,HOUR_MINUTE ,HOUR_SECOND ,MINUTE ,MINUTE_SECOND,MONTH ,SECOND ,YEAR 
 
再说一个小技巧:
比如想要在存储过程中使用"show tables";
可以使用
" SELECT `table_name` FROM `information_schema`.`TABLES`  WHERE `TABLE_SCHEMA`= 'banksys'"

替换。因为show tables 的结果并不能像select的结果这样循环。

 
电商去重:
-- 将电商domain查询,格式化,查询是否有,没有则增加,更新资讯
drop PROCEDURE if EXISTS `mall_domain_format`;
CREATE PROCEDURE mall_domain_format()
BEGIN
declare a_mall_id,target_mall_id,number,affect_number,target_is_abroad integer;
DECLARE a_domain,format_domain varchar(255);
declare found boolean DEFAULT true;
DECLARE mall_cursor cursor for select mall_id,domain from `wlt_mall` order by mall_id asc;
declare CONTINUE HANDLER for not found set found=false;
open mall_cursor;
fetch mall_cursor into a_mall_id,a_domain;
set number = 0;
-- select found;
while found DO
set number = number+1;
-- select a_mall_id,a_domain;
-- 格式化a_domain
-- 查找是否存在 该电商
-- 存在则更新 ;不存在则插入,更新 set format_domain = format_domain(a_domain);
-- select format_domain;
select mall_id into target_mall_id from `wlt_mall` where domain=format_domain limit 1;
-- select target_mall_id,format_domain,a_mall_id;
if ISNULL(target_mall_id) THEN
INSERT INTO `wlt_mall` (`mall_id`, `mall_name`, `domain`) VALUES (null, '', format_domain);
-- SELECT LAST_INSERT_ID() into target_mall_id;
-- select 'insert into run',target_mall_id;
end if;
select mall_id,is_abroad into target_mall_id,target_is_abroad from `wlt_mall` where domain=format_domain limit 1;
-- select 'not run insert into',target_mall_id;
if target_mall_id != a_mall_id THEN
-- select concat('select count(1) into affect_number from zx_article where mall_id=',a_mall_id,';');
-- select concat('update zx_article set mall_id=',target_mall_id,' where mall_id=',a_mall_id); -- select concat('select count(1) into affect_number from zx_article where mall_id=',a_mall_id,';');
select count(1) into affect_number from zx_article where mall_id=a_mall_id;
-- SELECT a_mall_id,affect_number,'hehe';
update zx_article set mall_id=target_mall_id,is_abroad=target_is_abroad where mall_id=a_mall_id;
update wlt_mall set article_number=article_number+affect_number where mall_id=target_mall_id;
delete from wlt_mall where mall_id=a_mall_id;
-- select 'run merge',target_mall_id,a_mall_id;
end IF;
fetch mall_cursor into a_mall_id,a_domain;
end while;
close mall_cursor; select number; END call mall_domain_format(); select * FROM zx_article where mall_id=337; select * from wlt_mall where mall_id=337;
select * from wlt_mall where domain like '%ba.de%'; -- 386
select count(1) from `wlt_mall` order by mall_id asc; INSERT INTO `walatao_info`.`wlt_mall` (`mall_id`, `mall_name`, `domain`, `country`, `is_abroad`, `introduce`, `comment`, `logo`, `article_number`, `product_number`, `display_order`, `status`) VALUES (null, 'm.taobao.com', 'm.taobao.com', '', '0', '', '', '', '1', '0', '0', '1'); drop function if EXISTS format_domain;
create function format_domain(domain varchar(255))
returns varchar(255)
BEGIN
-- 替换掉http:// https://,替换掉/ 查找最后出现的.,查找倒数第二个点
declare return_str varchar(255) default '';
declare source_domain VARCHAR(255) DEFAULT '';
declare flag TINYINT(1) DEFAULT 0;
set domain = LTRIM(domain);
set domain = RTRIM(domain);
set domain = REPLACE(domain,'http://','');
set domain = REPLACE(domain,'https://','');
set domain = REPLACE(domain,'/','');
set source_domain = LOWER(domain);
set domain = SUBSTRING_INDEX(domain, '.', -2);
case domain
when 'com.cn' THEN
set flag = 1;
when 'com.hk' THEN
set flag = 1;
when 'net.cn' THEN
set flag = 1;
when 'com.au' THEN
set flag = 1;
when 'co.nz' THEN
set flag = 1;
when 'co.uk' THEN
set flag = 1;
when 'co.jp' THEN
set flag = 1;
when 'cn.com' THEN
set flag = 1;
ELSE
set flag = 0;
end case;
if flag=1 then
set return_str = SUBSTRING_INDEX(source_domain, '.', -3);
ELSE
set return_str = domain;
end if;
return return_str;
END

  在上面的Sql中有个地方需要注意:如果在循环中如有select...into... from table....;结构的语句,会将continue handler标志重置成该sql的标志。会使循环不准。

导致的结果是外层循环还没有结束,里面的continue handler的标志的值就为0了,不满足循环。以下是对该功能的改版。

select count(1) 不会有这种情况。这可能是mysql的bug。

-- 将电商domain查询,格式化,查询是否有,没有则增加,更新资讯
drop PROCEDURE if EXISTS `mall_domain_format`;
CREATE PROCEDURE mall_domain_format()
BEGIN
declare a_mall_id,target_mall_id,number,affect_number,target_is_abroad,insert_target_mall_id,format_domain_number integer DEFAULT 0;
DECLARE a_domain,format_domain varchar(255);
declare found boolean DEFAULT true;
DECLARE mall_cursor cursor for select mall_id,domain from `wlt_mall` order by mall_id asc;
declare CONTINUE HANDLER for not found set found=false;
open mall_cursor;
fetch mall_cursor into a_mall_id,a_domain;
set number = 0;
-- select found;
while found DO
set number = number+1;
set target_mall_id = null;
set format_domain=null;
set format_domain_number = 0;
-- select a_mall_id,a_domain;
-- 格式化a_domain
-- 查找是否存在 该电商
-- 存在则更新 ;不存在则插入,更新 set format_domain = format_domain(a_domain);
-- select format_domain;
select count(1) into format_domain_number from `wlt_mall` where domain=format_domain limit 1;
-- select target_mall_id,format_domain,a_mall_id; if format_domain_number=0 THEN
INSERT INTO `wlt_mall` (`mall_id`, `mall_name`, `domain`) VALUES (null, '', format_domain);
-- SELECT LAST_INSERT_ID() into insert_target_mall_id;
-- select 'insert into run',target_mall_id;
end if; -- debug
/*
if format_domain='rakuten.com' || target_mall_id is NULL || a_mall_id is NULL || number=7 || number=8 || number=9 THEN
-- SELECT target_mall_id,format_domain,a_mall_id,'a',found;
select mall_id,is_abroad into target_mall_id,target_is_abroad from `wlt_mall` where domain=format_domain limit 1;
-- SELECT target_mall_id,format_domain,a_mall_id,'b',found;
INSERT INTO `error_log` (`error_id`, `error_log`) VALUES (null, concat('insert_target_mall_id:',insert_target_mall_id,' target_mall_id:',target_mall_id,' format_domain:',format_domain));
end if;
*/
select mall_id,is_abroad into target_mall_id,target_is_abroad from `wlt_mall` where domain=format_domain limit 1;
-- end debug
-- select 'not run insert into',target_mall_id;
if target_mall_id != a_mall_id THEN
-- select concat('select count(1) into affect_number from zx_article where mall_id=',a_mall_id,';');
-- select concat('update zx_article set mall_id=',target_mall_id,' where mall_id=',a_mall_id); -- select concat('select count(1) into affect_number from zx_article where mall_id=',a_mall_id,';');
select count(1) into affect_number from zx_article where mall_id=a_mall_id;
-- SELECT a_mall_id,affect_number,'hehe';
update zx_article set mall_id=target_mall_id,is_abroad=target_is_abroad where mall_id=a_mall_id;
update wlt_mall set article_number=article_number+affect_number where mall_id=target_mall_id;
delete from wlt_mall where mall_id=a_mall_id;
-- select 'run merge',target_mall_id,a_mall_id;
end IF; fetch mall_cursor into a_mall_id,a_domain;
end while;
close mall_cursor; select number,a_mall_id,a_domain,found,format_domain,target_mall_id; END

  

Mysql存储过程知识,案例--mysql存储过程基本函数的更多相关文章

  1. MySQL基础知识-安装MySQL

    前导: 昨天去参加了一个面试,公司不太大,是一家日资企业,在国内有几家分公司,面试官问到了MySQL的基本操作和性能优化,说了一大堆,倒是比较轻松的过了,但是面试结束之后,想了一下,基本操作忘的还是挺 ...

  2. MySQL基础知识:MySQL Connection和Session

    在connection的生命里,会一直有一个user thread(以及user thread对应的THD)陪伴它. Connection和Session概念 来自Stackoverflow的一个回答 ...

  3. MySQL数据库入门到高薪培训教程(从MySQL 5.7 到 MySQL 8.0)

    一.MySQL数据库入门到高薪培训视频教程(从MySQL5.7到MySQL8.0) 本套MySQL学习教程地址: https://edu.51cto.com/course/18034.html 为满足 ...

  4. MYSQL 存储过程1、SQL存储过程的基础知识

    在深入理解MySq之前,我们先理下一些简单的问题 Q:什么是存储过程?(stored procedure) A:是一段写好的SQL代码,特别的就是它是存在数据库的目录里.所以外部程序可以直接调用数据库 ...

  5. MySQL拓展 视图,触发器,事务,存储过程,内置函数,流程控制,索引,慢查询优化,数据库三大设计范式

    视图: 1.什么是视图 视图就是通过查询得到一张虚拟表,然后保存下来,下次直接使用即可 2.为什么要用视图 如果要频繁使用一张虚拟表,可以不用重复查询 3.如何使用视图 create view tea ...

  6. mysql 总结二(自定义存储过程)

    mysql执行流程: sql命令--->mysql引擎-----(分析)---->语法正确-----(编译)--->可识别命令----(执行)---->执行结果---(返回)- ...

  7. MySQL存储过程详解 mysql 存储过程

    原文地址:MySQL存储过程详解  mysql 存储过程作者:王者佳暮 mysql存储过程详解 1.     存储过程简介 我们常用的操作数据库语言SQL语句在执行的时候需要要先编译,然后执行,而存储 ...

  8. MySQL存储过程详解 mysql 存储过程(二)

    mysql存储过程详解 1.      存储过程简介 我们常用的操作数据库语言SQL语句在执行的时候需要要先编译,然后执行,而存储过程(Stored Procedure)是一组为了完成特定功能的SQL ...

  9. Mysql触发器、模糊查找、存储过程、内置函数

    原本觉得Mysql的一些知识还是差不多了,但是在实际上在项目上用的时候,发现什么都忘记了.现在重新回顾一下,顺便做个笔记. 触发器                                    ...

随机推荐

  1. 线段树练习[单点更新] HDU 2795 Billboard

    题目大意:有一个h*w的公告榜,可以依次在上面添加信息.每个信息的长度为x,高为1. 优先在最上面加入,如果空间足够的话,然后优先放在最左面.统计每条公告最终的位置,即它所在的行数. 这里是线段树来存 ...

  2. hdu 1039 Easier Done Than Said? 字符串

    Easier Done Than Said?                                                                     Time Limi ...

  3. qsettings 中文键值 注释 支持

    #ifndef SETTINGS_H #define SETTINGS_H #include <QString> #include <QVariant> class QSett ...

  4. 【转】针对iOS VS. Android开发游戏的优劣——2013-08-25 17

    http://game.dapps.net/gamedev/experience/8670.html 问题:如果你正在一个新工作室开发一款新的平板/手机游戏,你会选择iOS还是Android? 回答: ...

  5. Java基础知识强化之集合框架笔记73:如何选择使用哪种集合

    1. 到底使用那种集合.    看需求 是否是键值对象形式: 是:Map 键是否需要排序: 是:TreeMap 否:HashMap 不知道,就使用HashMap. 否:Collection 元素是否唯 ...

  6. jquery的效果地址

    http://www.cnblogs.com/lhb25/p/50-jquery-plugins-g.html

  7. [转]ORACLE 绑定变量用法总结

    转:http://blog.csdn.net/wanghai__/article/details/4778343 在oracle 中,对于一个提交的sql语句,存在两种可选的解析过程, 一种叫做硬解析 ...

  8. 完全用LINUX工作

    http://blog.csdn.net/e6894853/article/details/7881091 下面列出我常用的一些 Linux 程序.一个列表里可能有很多,那是为了方便你来选择,我列出了 ...

  9. pcap支持Python2.7.8解决办法

    pcap库只支持到python2.5. pip install pcap在python2.7.8找不到. 只需要将网盘的2个文件放到python安装目录下lib/site-package文件夹即可 链 ...

  10. My97DatePicker 没有权限问题

    引自:http://blog.sina.com.cn/s/blog_4b7809800100wkv4.html 今天遇到了My97DatePicker在不同IE版本中使用时有时出现没有权限错误的问题, ...