Tables
Create Tables
CREATE TABLE dbo.PurchaseOrderDetail ( PurchaseOrderID int NOT NULL ,LineNumber smallint NOT NULL ,ProductID int NULL ,UnitPrice money NULL ,OrderQty smallint NULL ,ReceivedQty float NULL ,RejectedQty float NULL ,DueDate datetime NULL );
Delete Columns from a Table
To delete columns
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In Object Explorer, connect to an instance of Database Engine.
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On the Standard bar, click New Query.
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Copy and paste the following example into the query window and click Execute.
USE AdventureWorks2012; GO ALTER TABLE dbo.doc_exb DROP COLUMN column_b ;
If the column contains constraints or other dependencies, an error message will be returned. Resolve the error by deleting the referenced constraints.
For additional examples, see .
ALTER TABLE dbo.tbm_cta_CustomTableDROP COLUMN EnableHistory
Insert
insert into people(id,name)values(1,'chucklu')insert into people(id,name)values(2,'lihu')
insert into toys(id,name,people_id)values(1,'a',1)insert into toys(id,name,people_id)values(1,'b',2)insert into toys(id,name,people_id)values(1,'c',1)insert into toys(id,name,people_id)values(1,'d',2)insert into toys(id,name,people_id)values(1,'e',1)
User-defined Functions
Create
示例,创建一个名为HelloWorld4的函数,不需要输入参数
CREATE FUNCTION HelloWorld4()RETURNS VARCHAR(20)ASBEGINRETURN 'Hello World!';END select dbo.helloworld4()
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PostgreSQL中的CreateFunction
调用自定义函数的方式
SELECT dbo.udf_GetHistoryTableNameByTableCode('MemberRole',5)
udf_GetHistoryTableNameByTableCode为函数名,后面2个是参数
查询数据库版本
select @@version
Microsoft SQL Server 2008 (SP4) - 10.0.6241.0 (X64)
Apr 17 2015 10:56:08 Copyright (c) 1988-2008 Microsoft CorporationStandard Edition (64-bit) on Windows NT 6.1 <X64> (Build 7601: Service Pack 1) (VM)
声明xml变量,并进行查询
DECLARE @OrderItems xml =N''SELECT S.value('ProductID[1]', 'int') AS ProductID ,S.value('Quantity[1]', 'int') AS Quantity ,S.value('LanCode[1]', 'NVARCHAR(100)') AS LanCode ,S.value('IsPromotion[1]', 'int') AS IsPromotionFROM @OrderItems.nodes('Orders/Order') AS T ( S ) 22440 1 0
declare @p1 xmlset @p1=convert(xml,N'')SELECT T.Item.value('@MemberID', 'int') AS [MemberID]FROM @p1.nodes('Members/Member') AS T(Item)
获取指定数据库的,所有用户自定义的数据表
SELECT TABLE_NAMEFROM INFORMATION_SCHEMA.TABLESWHERE TABLE_TYPE = 'BASE TABLE' AND TABLE_CATALOG = 'DatabaseName'
普通打印
Print N'Chuck'
Print无法打印出拼接的sql
可能是因为拼接的sql中的某一个变量为空
Select Into
异常:An object or column name is missing or empty. For SELECT INTO statements, verify each column has a name. For other statements, look for empty alias names. Aliases defined as "" or [] are not allowed. Change the alias to a valid name.
在select静态列的时候,需要给静态列起一个列名。
Alert
向数据表新增一个列
IF NOT EXISTS ( SELECT 1FROM sysobjectsINNER JOIN syscolumns ON sysobjects.id = syscolumns.idWHERE sysobjects.name = N'tbm_den_DynamicEntity'AND syscolumns.name = N'EnableHistory')ALTER TABLE [dbo].[tbm_den_DynamicEntity]ADD EnableHistory BIT;
Stored Procedures
Delete
DROP PROCEDURE; GO
查询一个表有多少列
SELECT *FROM Northwind.INFORMATION_SCHEMA.COLUMNSWHERE TABLE_NAME = N'Customers'