use kgc;
create table location (Region char(20),store_name char(20));
insert into location values ('East','Boston') ;
insert into location values ('East','New York');
insert into location values ('west','Los Angeles');
insert into location values ('west','Houston') ;

create table Store_Info (Store_Name char(20),sales int(10),Date char(10));
insert into Store_Info values ('Los Angeles','1500','2020-12-05');
insert into Store_Info values ('Houston','250','2020-12-07');
insert into Store_Info values ('Los Angeles','300','2020-12-08');
insert into Store_Info values ('Boston','700','2020-12-08');

---- SELECT ---- 顯示表格中一個(gè)或數(shù)個(gè)欄位的所有資料
語(yǔ)法: SELECT "欄位" FROM "表名";
SELECT Store_Name FROM Store_Info;

---- DISTINCT ---- 不顯示重復(fù)的資料
語(yǔ)法: SELECT DISTINCT "欄位" FROM "表名";
SELECT DISTINCT Store_Name FROM Store_Info;

---- WHERE ---- 有條件查詢
語(yǔ)法:SELECT "欄位” FROM "表名" WHERE "條件";
SELECT Store_Name FROM Store_Info WHERE Sales > 1000;

---- AND OR ---- 且 或
語(yǔ)法:SELECT "欄位" FROM "表名” WHERE "條件1" {[ANDIOR] "條件2"}+;
SELECT Store_Name FROM Store_Info WHERE Sales > 1000 OR (Sales < 500 AND Sales > 200);

---- IN ---- 顯示己知的值的資料
語(yǔ)法: SELECT "欄位" FROM "表名" WHERE "欄位" IN ('值1','值2', ...);
SELECT * FROM Store_Info WHERE Store_Name IN ('Los Angeles','Houston');

---- BETWEEN ---- 顯示兩個(gè)值范圍內(nèi)的資料
語(yǔ)法:SELECT "欄位" FROM "表名" WHERE "欄位" BETWEEN '值1' AND '值2';
SELECT * FROM Store_Info WHERE Date BETWEEN '2020-12-06' AND '2020-12-10';

---- 通配符 ---- 通常通配符都是跟LIKE一起使用的
% : 百分號(hào)表示零個(gè)、一個(gè)或多個(gè)字符
_ : 下劃線表示單個(gè)字符

'A_Z':所有以‘A'起頭，另一個(gè)任何值的字符，且以Z'為結(jié)尾的字符串。例如，'A.BZ'和‘A.22'都符合這一個(gè)模式，而‘AKK2'并不符合(因?yàn)樵贏和Z之間有兩個(gè)字符，而不是一個(gè)字符)。
'ABC%':所有以'ABC'起頭的字符串。例如，'ABCD'和'ABCABC'都符合這個(gè)模式。
'%XYZ':所有以'XYZ'結(jié)尾的字符串。例如，'WXYZ'和‘ZZXYZ'都符合這個(gè)模式。
'%AN%':所有含有'AN'這個(gè)模式的字符串。例如，'LOS ANGELES'和'SAN FRANCISCO'都符合這個(gè)模式。
'_AN%':所有第二個(gè)字母為‘A'和第三個(gè)字母為'N'的字符串。例如，'SAMN FRANCITSCO'符合這個(gè)模式，而'LOS ANGELES'則不符合這個(gè)模式。
---- LIKE ---- 匹配一個(gè)模式來(lái)找出我們要的資料
語(yǔ)法:SELECT "欄位" FROM "表名" WHERE "欄位" LIKE {模式};
SELECT * FROM Store_Info WHERE Store_Name like '%os%';
---- ORDER BY ---- 按關(guān)鍵字排序
語(yǔ)法:SELECT "欄位" FROM "表名" [WHERE "條件"] ORDER BY "欄位" [ASC，DESC];
#ASC是按照升序進(jìn)行排序的,是默認(rèn)的排序方式。
#DESC是按降序方式進(jìn)行排序。
SELECT Store_Name,Sales,Date FROM Store_Info ORDER BY Sales DESC;

abs(x)                #返回x的絕對(duì)值
rand()                #返回0到1的隨機(jī)數(shù)
mod(x,y)              #返回x除以y以后的余數(shù)
power(x,y)            #返回x的y次方
round(x)              #返回離x最近的整數(shù)
round(x,y)            #保留x的y位小數(shù)四舍五入后的值
sqrt(x)               #返回x的平方根
truncate(x,y)         #返回?cái)?shù)字x截?cái)酁閥位小數(shù)的值
ceil(×)               #返回大于或等于x的最小整數(shù)
floor(x)              #返回小于或等于x的最大整數(shù)
greatest(x1,x2...)    #返回集合中最大的值
least(x1,x2...)       #返回集合中最小的值


SELECT abs(-1),rand(),mod(5,3),power(2,3),round(1.89);
SELECT round(1.8937,3),truncate(1.235,2),ceil(5.2),floor(2.1),least(1.89,3,6.1,2.1);

聚合函數(shù):
avg()       #返回指定列的平均值
count()     #返回指定列中非 NULL值的個(gè)數(shù)
min()       #返回指定列的最小值
max()       #返回指定列的最大值
sum(x)      #返回指定列的所有值之和

SELECT avg(Sales) FROM Store_Info;

SELECT count(store_Name) FROM Store_Info;
SELECT count(DISTINCT store_Name) FROM Store_Info;

SELECT max(Sales) FROM Store_Info;
SELECT min(sales) FROM Store_Info;

SELECT sum(sales) FROM Store_Info;

SELECT count(DISTINCT store_Name) FROM Store_Info;
SELECT count(*) FROM Store_Info;
#count(*)包括了所有的列的行數(shù)，在統(tǒng)計(jì)結(jié)果的時(shí)候，不會(huì)忽略列值為NULL
#count(列名)只包括列名那一列的行數(shù)，在統(tǒng)計(jì)結(jié)果的時(shí)候，會(huì)忽略列值為NULL的行

字符串函數(shù):
trim()             #返回去除指定格式的值
concat(x,y)        #將提供的參數(shù)x和y拼接成一個(gè)字符串
substr(x,y)        #獲取從字符串x中的第y個(gè)位置開始的字符串，跟substring()函數(shù)作用相同
substr(x,y,z)      #獲取從字符串x中的第y個(gè)位置開始長(zhǎng)度為z的字符串
length(x)          #返回字符串x的長(zhǎng)度
replace(x,y,z)     #將字符串z替代字符串x中的字符串y
upper(x)           #將字符串x的所有字母變成大寫字母
lower(x)           #將字符串x的所有字母變成小寫字母
left(x,y)          #返回字符串x的前y個(gè)字符
right(x,y)         #返回字符串x的后y個(gè)字符
repeat(x,y)        #將字符串x重復(fù)y次
space(x)           #返回x個(gè)空格
strcmp (x,y)       #比較x和y，返回的值可以為-1,0,1
reverse(x)         #將字符串x反轉(zhuǎn)

SELECT concat(Region,Store_Name) FROM location WHERE Store_Name = 'Boston';

#如sql_mode開啟開啟了PIPES_AS_CONCAT，"||"視為字符串的連接操作符而非或運(yùn)算符,和字符串的拼接函數(shù)concat相類似，這和Oracle數(shù)據(jù)庫(kù)使用方法一樣的
SELECT Region || ' ' || Store_Name FROM location WHERE Store_Name = 'Boston';

SELECT substr(Store_Name,3) FROM location WHERE Store_Name = 'Los Angeles';
SELECT substr(Store_Name,2,4) FROM location WHERE Store_Name = 'New York';

SELECT TRIM ([ [位置] [要移除的字符串] FROM ] 字符串);
#[位置]:的值可以為 LEADING(起頭)，TRAILING(結(jié)尾)，BOTH(起頭及結(jié)尾)。
#[要移除的字符串]:從字串的起頭、結(jié)尾，或起頭及結(jié)尾移除的字符串。缺省時(shí)為空格

SELECT TRIM(LEADING 'Ne' FROM 'New York');

SELECT Region,length(Store_Name) FROM location;

SELECT REPLACE(Region,'ast','astern')FROM location;

---- GROUP BY ----  對(duì)GROUP BY后面的欄位的查詢結(jié)果進(jìn)行匯總分組，通常是結(jié)合聚合函數(shù)一起使用的
GROUP BY有一個(gè)原則，就是SELECT后面的所有列中，沒有使用聚合函數(shù)的列，必須出現(xiàn)在GROUP BY后面。

語(yǔ)法:SELECT "欄位1",SUM("欄位2") FROM "表名" GROUP BY "欄位1";
SELECT Store_Name,SUM(Sales) FROM Store_Info GROUP BY Store_Name ORDER BY sales desc;

---- HAVING ---- 用來(lái)過濾由GROUP BY語(yǔ)句返回的記錄集，通常與GROUP BY語(yǔ)句聯(lián)合使用
HAVING語(yǔ)句的存在彌補(bǔ)了wHERE關(guān)鍵字不能與聚合函數(shù)聯(lián)合使用的不足。如果被SELECcT的只有函數(shù)欄，那就不需要GROUP BY子句。

語(yǔ)法:SELECT "欄位1",SUM("欄位2") FROM "表格名" GROUP BY "欄位1" HAVING (函數(shù)條件);
SELECT Store_Name,SUM(Sales) FROM Store_Info GROUP BY Store_Name HAVING SUM (Sales) > 1500;

---- 別名 ---- 欄位別名表格別名

語(yǔ)法:SELECT "表格別名"."欄位1” [AS] "欄位別名" FROM "表格名" [AS] "表格別名"
SELECT A.Store_Name Store，SUM(A.Sales) "Total Sales" FROM Store_Info A GROUP BY A.Store_Name;

---- 子查詢 ---- 連接表格，在WHERE子句或 HAVING子句中插入另一個(gè) SQL語(yǔ)句

語(yǔ)法: SELECT "欄位1" FROM "表格1" WHERE "欄位2" [比較運(yùn)算符]       #外查詢
(SELECT "欄位1" FROM "表格2" WHERE "條件");                       #內(nèi)查詢

可以是符號(hào)的運(yùn)算符，例如 =、>、<、>=、<= ;也可以是文字的運(yùn)算符，例如LIKE、IN、BETWEEN
SELECT SUM(Sales) FROM Store_Info WHERE Store_Name IN
(SELECT Store_Name FROM location WHERE Region = 'west');

SELECT SUM(A.Sales) FROM Store_Info A WHERE A.Store_Name IN
(SELECT Store_Name FROM location B WHERE B.Store_Name = A.Store_Name);

---- EXISTS ---- 用來(lái)測(cè)試內(nèi)查詢有沒有產(chǎn)生任何結(jié)果，類似布爾值是否為真
#如果有的話，系統(tǒng)就會(huì)執(zhí)行外查詢中的SQL語(yǔ)句。若是沒有的話，那整個(gè)SQL語(yǔ)句就不會(huì)產(chǎn)生任何結(jié)果。
語(yǔ)法: SELECT "欄位1" FROM "表格1" WHERE EXISTS (SELECT * FROM "表格2" WHERE "條件");
SELECT SUM(Sales) FROM Store_Info WHERE EXISTS (SELECT * FROM location WHERE Region = 'West');

UPDATE Store_Info SET store_name='washington'WHERE sales=300;

inner join(內(nèi)連接):只返回兩個(gè)表中聯(lián)結(jié)字段相等的行
left join(左連接):返回包括左表中的所有記錄和右表中聯(lián)結(jié)字段相等的記錄
right join(右連接):返回包括右表中的所有記錄和左表中聯(lián)結(jié)字段相等的記錄

SELECT * FROM location A INNER JOIN Store_Info B on A.Store_Name = B.store_Name ;

SELECT * FROM location A RIGHT JOIN Store_Info B on A.Store_Name = B.Store_Name ;

SELECT * FROM location A,store_Info B WHERE A.Store_Name = B.Store_Name;

SELECT A.Region REGION,SUM(B.Sales) SALES FROM location A,Store_Info B
WHERE A.Store_Name = B.Store_Name GROUP BY REGION;

---- CREATE VIEW ---- 視圖，可以被當(dāng)作是虛擬表或存儲(chǔ)查詢。
·視圖跟表格的不同是，表格中有實(shí)際儲(chǔ)存資料，而視圖是建立在表格之上的一個(gè)架構(gòu)，它本身并不實(shí)際儲(chǔ)存資料。
·臨時(shí)表在用戶退出或同數(shù)據(jù)庫(kù)的連接斷開后就自動(dòng)消失了，而視圖不會(huì)消失。
·視圖不含有數(shù)據(jù)，只存儲(chǔ)它的定義，它的用途一般可以簡(jiǎn)化復(fù)雜的查詢。比如你要對(duì)幾個(gè)表進(jìn)行連接查詢，而且還要進(jìn)行統(tǒng)計(jì)排序等操作，寫SQT語(yǔ)句會(huì)很麻煩的，用視圖將幾個(gè)表聯(lián)結(jié)起來(lái)，然后對(duì)這個(gè)視圖進(jìn)行查詢操作，就和對(duì)一個(gè)表查詢一樣，很方便。

語(yǔ)法:CREATE VIEW "視圖表名” AS "SELECT語(yǔ)句";
CREATE VIEW V_REGION_SALES AS SELECT A.Region REGION, SUM(B.Sales) SALES FROM location A
INNER JOIN Store_Info B ON A.Store_Name = B.Store_Name GROUP BY REGION;

SELECT * FROM V_REGION_SALES;
DROP VIEW V_REGION_SALES;

---- UNION ---- 聯(lián)集，將兩個(gè)SQL語(yǔ)句的結(jié)果合并起來(lái)，兩個(gè)SQI語(yǔ)句所產(chǎn)生的欄位需要是同樣的資料種類
UNION:生成結(jié)果的資料值將沒有重復(fù)，且按照字段的順序進(jìn)行排序
語(yǔ)法:[SELECT 語(yǔ)句 1] UNION [SELECT 語(yǔ)句2];

UNION ALL:將生成結(jié)果的資料值都列出來(lái)，無(wú)論有無(wú)重復(fù)
語(yǔ)法:[SELECT 語(yǔ)句 1] UNION ALL [SELECT 語(yǔ)句 2];

SELECT Store_Name FROM location UNION SELECT Store_Name FROM Store_Info;

SELECT Store_Name FROM location UNION ALL SELECT Store_Name FROM Store_Info;

----- 交集值 ---- 取兩個(gè)SQL語(yǔ)句結(jié)果的交集
SELECT A.Store_Name FROM location A INNER JOIN Store_Info B ON A.Store_Name = B.Store_Name;
SELECT A.Store_Name FROM location A INNER JOIN Store_Info B USING(Store_Name);

#兩表基中的一個(gè)表沒有指定的行，而另一個(gè)表這個(gè)行有重復(fù)，并且確實(shí)有交集的時(shí)候用
SELECT A.Store_Name FROM
(SELECT Store_Name FROM location UNION ALL SELECT Store_Name FROM store_Info) A
GROUP BY A.Store_Name HAVING COUNT(*) > 1;

#取兩個(gè)sQL語(yǔ)句結(jié)果的交集,且沒有重復(fù)
SELECT A.Store_Name FRONM (SELECT B.Store_Name FROM location B INNER JOIN Store_Info C ON B.Store_Name = C.store_Name) A
GROUP BY A.Store_Name;

SELECT DISTINCT A.Store_Name FROM location A INNER JOIN Store_Info B USING(Store_Name);

SELECT DISTIMCT Store_Name FROM location WHERE (Store_Name) IN (SELECT Store_Name FROM Store_Info);

SELECT DISTINCT A.Store_Name FROM location A LEFT JOIN Store_Info B USING(Store_Name) WHERE B.Store_Name IS NOT NULL;

---- 無(wú)交集值 ---- 顯示第一個(gè)sQL語(yǔ)句的結(jié)果，且與第二個(gè)SQL語(yǔ)句沒有交集的結(jié)果，且沒有重復(fù)
SELECT DISTINCT Store_Name FROM location WHERE (Store_Name) NOT IN (SELECT Store_Name FROM Store_Info);

SELECT DISTINCT A.Store_Name FROM location A LEFT JOIN Store_Info B USING(Store_Name) WHERE B.Store_Name IS NULL;

---- CASE ---- 是 SQL 用來(lái)做為 IF-THEN-ELSE 之類邏輯的關(guān)鍵字
語(yǔ)法:
SELECT CASE ("欄位名")
  WHEN "條件1” THEN "結(jié)果1"
  WHEN "條件2" THEN "結(jié)果2"
  ...
  [ELSE "結(jié)果N"]
  END
FROM "表名";

#"條件"可以是一個(gè)數(shù)值或是公式。ELSE子句則并不是必須的。

SELECT store_Name, CASE Store_Name
  WHEN 'Los Angeles' THEN Sales * 2
  WHEN 'Boston' THEN Sales * 1.5
  ELSE Sales
  END
"New Sales",Date
FROM Store_Info;

#"New Sales"是用于CASE 那個(gè)欄位的欄位名。

CREATE TABLE Total_Sales (Name char(10),sales int(5));
INSERT INTO Total_Sales VALUES ('zhangsan',10);
INSERT INTO Total_Sales VALUES ('lisi',15);
INSERT INTO Total_Sales VALUES ('wangwu',20);
INSERT INTO Total_Sales VALUES ('zhaoliu',40);
INSERT INTO Total_Sales VALUES ('sunqi',50);
INSERT INTO Total_Sales VALUES ('zhouba',20);
INSERT INTO Total_Sales VALUES ('wujiu',30);

----算排名----表格自我連結(jié)(Self Join)，然后將結(jié)果依序列出，算出每一行之前〈包含那一行本身)有多少行數(shù)
SELECT A1.Name, A1.sales,COUNT(A2.sales) Rank FROM Total_sales A1,Total_sales A2
WHERE A1.sales < A2.sales 0R (A1.sales = A2.sales AND A1.Name = A2.Name)
GROUP BY A1.Name, A1.sales ORDER BY A1.sales DESC;

例如：
select A1.Name,A1.sales,count(A2.sales) rank from Total_Sales A1,Total_Sales A2 where A1.sales <  A2.sales OR (A1.sales=A2.sales and A1.Name=A2.Name) group by A1.Name order by A1.sales desc;

解釋：
當(dāng)A1的sales字段值小于A2的sales字段值、或者兩表sales字段值相等并且Name字段值相等時(shí)，
從A1和A2表中查詢A1的Name字段值、A1的sales字段值、和A2的sales字段的非空值rank是別名，并為A1的Name字段分組，A1的sales字段降序排序

---- 算中位數(shù) ----
SELECT Sales Middle FROM (SELECT A1.Name,A1.Sales,COUNT(A2.Sales) Rank FROM Total_Sales A1,Total_Sales A2
WHERE A1.Sales < A2.Sales 0R (A1.Sales = A2.Sales AND A1.Name >= A2.Name)
GROUP BY A1.Name,A1.Sales ORDER BY A1.Sales DESC) A3
WHERE A3.Rank = (SELECT (COUNT(*)+1) DIV 2 FROM Total_Sales);

例如：
select * from (select A1.Name,A1.sales,count(A2.sales) rank from Total_Sales A1,Total_Sales A2 where A1.sales < A2.sales OR (A1.sales=A2.sales and A1.Name=A2.Name) group by A1.Name order by A1.sales desc) A3 where A3.rank = (select (count(*)+1) DIV 2 from Total_Sales);

select sales mid from (select A1.Name,A1.sales,count(A2.sales) rank from Total_Sales A1,Total_Sales A2 where A1.sales < A2.sales OR (A1.sales=A2.sales and A1.Name=A2.Name) group by A1.Name order by A1.sales desc) A3 where A3.rank = (select (count(*)+1) DIV 2 from Total_Sales);


#每個(gè)派生表必須有自己的別名，所以別名A3必須要有
#DIV 是在MySQL中算出商的方式

---- 算累積總計(jì) ---- 表格自我連結(jié)(Self Join)，然后將結(jié)果依序列出,算出每一行之前(包含那一行本身)的總合
SELECT A1.Name, A1.Sales, SUM(A2.Sales) Sum_Total FROM Total_Sales A1，Total_Sales A2
WHERE A1.Sales < A2.Sales OR (A1.Sales=A2.Sales AND A1.Name = A2.Name)
GROUP BY A1.Name,A1.Sales ORDER BY A1.Sales DESC;

例如：
select A1.*,sum(A2.sales) sum_soales from Total_Sales A1,Total_Sales A2 where A1.sales < A2.sales or(A1.sales=A2.sales and A1.Name=A2.Name) group by A1.Name order by A1.sales desc;

例如：
select A1.*,A1.sales/(select sum(sales) from Total_Sales) z_sum from Total_Sales A1,Total_Sales A2 where A1.sales < A2.sales or (A1.sales=A2.sales and A1.Name=A2.Name) group by A1.Name;

#select sum(sales) from Total_Sales 是為了算出字段值總合，然后每一行一一除以總合，算出每行的總合百分比。

例如：
select A1.Name,A1.sales,sum(A2.sales),sum(A2.sales)/(select sum(sales) from Total_Sales) Z from Total_Sales A1,Total_Sales A2 where A1.sales < A2.sales or (A1.sales=A2.sales and A1.Name=A2.Name) group by A1.Name order by A1.sales desc;

select A1.Name,A1.sales,sum(A2.sales),TRUNCATE(sum(A2.sales)/(select sum(sales) from Total_Sales),2) ||'%' Z from Total_Sales A1,Total_Sales A2 where A1.sales < A2.sales or (A1.sales=A2.sales and A1.Name=A2.Name) group by A1.Name order by A1.sales desc;

例如：
create table SITE(site varchar(20));
insert into SITE values('nanjing');
insert into SITE values('beijing');
insert into SITE values('');
insert into SITE values('taijin');
insert into SITE values();
insert into SITE values('');
select * from SITE;	

select length(site) from SITE;
select * from SITE where site is NULL;
select * from SITE where site is not NULL;
select * from SITE where site ='';
select * from SITE where site <> '';

匹配模式			描述									實(shí)例
^ 				匹配文本的開始字符 						‘^bd' 匹配以 bd 開頭的字符串
$ 				匹配文本的結(jié)束字符 						‘qn$' 匹配以 qn 結(jié)尾的字符串
. 				匹配任何單個(gè)字符							‘s.t' 匹配任何 s 和 t 之間有一個(gè)字符的字符串
* 				匹配零個(gè)或多個(gè)在它前面的字符 				‘fo*t' 匹配 t 前面有任意個(gè) o
+ 				匹配前面的字符 1 次或多次					‘hom+' 匹配以 ho 開頭，后面至少一個(gè)m 的字符串
字符串 			匹配包含指定的字符串 						‘clo' 匹配含有 clo 的字符串
p1|p2 			匹配 p1 或 p2 							‘bg|fg' 匹配 bg 或者 fg
[...] 			匹配字符集合中的任意一個(gè)字符 				‘[abc]' 匹配 a 或者 b 或者 c
[^...] 			匹配不在括號(hào)中的任何字符 					‘[^ab]' 匹配不包含 a 或者 b 的字符串
{n} 			匹配前面的字符串 n 次 					‘g{2}' 匹配含有 2 個(gè) g 的字符串
{n,m}			匹配前面的字符串至少 n 次，至多m 次		‘f{1,3}' 匹配 f 最少 1 次，最多 3 次

例如：
select * from Total_Sales where Name regexp '^[n]';
select * from Total_Sales where Name regexp '[n]';
select * from Total_Sales where Name regexp 'Ho|Bo';

語(yǔ)法：
DELIMITER !!    				#將語(yǔ)句的結(jié)束符號(hào)從分號(hào)；臨時(shí)修改，以防出問題，可以自定義
CREATE PROCEDURE XXX()  	#創(chuàng)建存儲(chǔ)過程，過程名自定義,（）可帶參數(shù)
 	BEGIN   		    	#過程體以關(guān)鍵字BEGIN開始
 	select * from xxx;  	#過程體語(yǔ)句
 	END!!    				#過程體以關(guān)鍵字END結(jié)尾
DELIMITER ; 			    	#將語(yǔ)句的結(jié)束符號(hào)恢復(fù)為分號(hào)

call XXX;	  				#調(diào)用存儲(chǔ)過程

====查看存儲(chǔ)過程====
show create procedure [數(shù)據(jù)庫(kù).]儲(chǔ)存過程名; 	  #查看某個(gè)儲(chǔ)存過程的具體信息
show create procedure XXX;
show procedure status [like '%XXX%'] \G

例如：
DELIMITER !!
CREATE PROCEDURE KIND1()
BEGIN
	select * from Total_Sales;
END!!

DELIMITER ;
CALL KIND1;

show create procedure KIND1\G
show procedure status like '%KIND1%'\G

例如：
DELIMITER !!
CREATE PROCEDURE KIND2(IN people char(20))
BEGIN
	select * from Total_Sales where Name=people;                                                    
END!!         

DELIMITER ;
CALL KIND2('lisi');

例如：
DELIMITER !!
CREATE PROCEDURE KIND7(IN num int(10))
BEGIN
declare var int;
set var=num*2;
if var>=10 then
	update Total_Sales set sales=sales+1;
else 
	update Total_Sales set sales=sales-1;
end if;
END!!
DELIMITER ;

CALL KIND7(5);
CALL KIND7(4);

例如：
create table akg(id int);

DELIMITER !!
CREATE PROCEDURE KIND6()
BEGIN
declare var int;
set var=0;
while var<5 do
	insert into akg values(var);
	set var=var+1;
end while;
END!!

DELIMITER ;
CALL KIND6;
select * from akg;