数据的更改

数据库/头歌/AVG() 函数的使用/AVG() 函数的使用.sh

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+USE Mall
+GO
+
+SET NOCOUNT ON
+
+------ return two columns that the price bigger than average price ------
+-- ********** Begin ********** --
+SELECT prod_name, prod_price
+FROM Products
+WHERE prod_price > (SELECT AVG(prod_price) FROM Products)
+-- ********** End ********** --
+
+GO

数据库/头歌/COUNT() 函数的使用/1. COUNT() 函数的使用.sh

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+USE Mall
+GO
+
+SET NOCOUNT ON
+
+------ return the number of product which price bigger than 10 -----
+-- ********** Begin ********** --
+SELECT COUNT(*) 
+FROM Products 
+WHERE prod_price > 10
+-- ********** End ********** --
+
+GO
+

数据库/头歌/使用WHERE语句进行检索/使用WHERE语句进行检索.sh

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+USE Mall
+Go
+
+SET NOCOUNT ON
+
+---------- retrieving with range ----------
+-- ********** Begin ********** --
+SELECT prod_name, prod_price
+FROM Products
+WHERE prod_price BETWEEN 3 AND 5;
+-- ********** End ********** --
+
+GO
+
+---------- retrieving with nomatches ----------
+-- ********** Begin ********** --
+SELECT prod_name, prod_price
+FROM Products
+WHERE prod_name <> 'Lion toy';
+-- ********** End ********** --
+
+GO

数据库/头歌/基本SELECT查询/基本SELECT查询.sh

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+USE Mall
+GO
+
+SET NOCOUNT ON
+
+---------- retrieving multiple column ----------
+-- ********** Begin ********** --
+SELECT prod_name, prod_price
+FROM Products;
+
+-- ********** End ********** --
+
+GO
+
+---------- retrieving all column ----------
+-- ********** Begin ********** --
+SELECT *
+FROM Products;
+
+-- ********** End ********** --
+
+GO

数据库/头歌/带限制条件的查询和表达式查询/带限制条件的查询和表达式查询.sh

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+USE Mall
+Go
+
+SET NOCOUNT ON
+
+---------- retrieving with limited ----------
+-- ********** Begin ********** --
+SELECT prod_name 
+FROM Products 
+WHERE prod_name LIKE '%toy%'
+-- ********** End ********** --
+GO
+
+---------- retrieving with expression ----------
+-- ********** Begin ********** --
+SELECT prod_price, prod_price * 0.8 AS discount_price
+FROM Products
+WHERE prod_price > 3
+-- ********** End ********** --
+GO

数据库/头歌/数据的更改/数据的更改.sh

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+-- ********** create database ********** --
+-- ********** Begin ********** --
+create database Books
+-- ********** End ********** --
+go
+
+use Books
+go
+
+-- ********** create table ********** --
+-- ********** Begin ********** --
+create table prices
+(
+    ID int IDENTITY(1,1) not null,
+    Name varchar(20) not null,
+    price varchar(30) not null
+)
+-- ********** End ********** --
+go
+
+SET NOCOUNT ON
+
+-- ********** insert ********** --
+-- ********** Begin ********** --
+insert into prices (Name, price) values ('Harry Potter', '$128')
+insert into prices (Name, price) values ('Walden', '$5')
+-- ********** End ********** --
+go
+
+SET NOCOUNT ON
+
+-- ********** update ********** --
+-- ********** Begin ********** --
+update prices set price = '$6' where Name = 'Walden'
+-- ********** End ********** --
+go

数据库/头歌/通配符%的使用/1. 通配符%的使用.sh

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+USE Mall
+Go
+
+SET NOCOUNT ON
+
+---------- retrieving with wildcard % ----------
+-- ********** Begin ********** --
+SELECT prod_id, prod_name, prod_price
+FROM Products
+WHERE prod_name LIKE '%toy%'
+-- ********** End ********** --
+
+GO

数据库/头歌/通配符_的使用/通配符_的使用.sh

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+USE Mall
+Go
+
+SET NOCOUNT ON
+
+---------- retrieving with wildcard _ ----------
+-- ********** Begin ********** --
+
+SELECT prod_id, prod_name, prod_price
+FROM Products
+WHERE prod_name LIKE '1_ inch%'
+
+-- ********** End ********** --
+
+GO