SQL Server

 I. You do not need to worry about the problem where 1 = 1 in Multi-condition queries.For example, if you query a page and have multiple options to query, you can also select and enter the query keyword on your own, the code is roughly as

In the previous article, we talked about the basic definition of SQL stored procedures, how to create and use them. This article describes how to use variables. Variable: local variable and global variable The local variable starts with @ and the

Method 1:Copy codeThe Code is as follows:Select * from (select Url, case when Month = 01 then 'february 'when Month = 02 then' February 'when Month = 03 then' February 'when Month = 04 then' February 'when Month = 05 then' February 'When Month = 06

1. Forget the logon password of a user except SYS and SYSTEM. Log On As a sys (or SYSTEM) user. Conn sys/PASS_WORD as sysdba; Use the following statement to modify the user password. Alter user user_name identified by newpass; Note: The password

Copy codeThe Code is as follows:On delete cascade When you update or delete a primary key table, the foreign key table will be updated or deleted together. You need to set cascade attributes when creating the table. Create table Countries

Recently, the domain name of the database needs to be rebalanced, because SQL is easy to use and can be sorted out. A. truncates N characters from the left of the string. Copy codeThe Code is as follows:Declare @ S1 varchar (100)Select @ S1 = 'HTTP:

1. Search for redundant duplicate records in the Table. duplicate records are determined based on a single field (peopleId ).Copy codeThe Code is as follows:Select * from peopleWhere peopleId in (select peopleId from people group by peopleId having

Question: consumers from Madrid who have less than 3 orders Table creation:Copy codeThe Code is as follows:Set nocount on -- when set nocount is ON, no count is returned (the number of rows affected by the Transact-SQL statement ). When set nocount

DML (Data Manipulation Language) and CTE (Common Table Expression)I did not know the meaning of the two abbreviations I encountered when I was reading a book today. So I wrote them here to facilitate the next review.About DML (Data Manipulation

When we want to update a dynamic table (that is, the data in the table is constantly added), we may use the database proxy to write homework, then, let him regularly query the latest data in the dynamic table, and then update the data. In this way,

Open SQLSERVER Configuration Manager, double-click with the left mouse to open the Properties dialog box, and select the Advanced tab to view the SQL version information. In the past, we often used the following statement to view the version

For a database, you need to know more about the basic SQL statements. Below are some basic SQL statements. Create problems • Show database; displays existing databases• Use database_x; database database_x should be used now• Create table coffee (id

Misunderstanding #22: Resource governor can control IOErrorResource tuning controllers cannot control I/O. We hope that the next version of SQL Server can support I/O control. IO control is helpful for reducing the performance impact on large table

In addition to the execution plan, there are other factors to consider when running a statement, such as the statement Compilation Time, execution time, and number of disk reads.If the DBA can test the problem statement separately, you can enable

1. sp_helpsort Select serverproperty ('colation ')View your sorting rules.However, this should be related to the character set.2. Change server sorting rules Changing the default sorting rules for SQL Server 2005 instances may be complicated by the

Shard creation 2004.4Copy codeThe Code is as follows:/* -- Call exampleExec p_lockinfo1--*/Alter proc p_lockinfo1@ Kill_lock_spid bit = 1, -- whether to kill the deadlock process; 1: Kill; 0: only show@ Show_spid_if_nolock bit = 1 -- if there is no

Every time we talk about the high availability of SQL Server, many DBAs, especially SQL Server DBAs, feel a pain: Because we all think that SQL Server cannot or is difficult to implement SQL Server. There are also a lot of DBA friends with a head

The first method is the most traditional method. The variable in the stored procedure is used as the page multiplier.Copy codeThe Code is as follows:[C-sharp] view plaincopyprint? Create proc p_paged1@ PageSize int, @ currentPage intAsSelect top (@

I have never liked the SQL concatenation method when accessing the database. The reasons are as follows:1. Insecure: there is a risk of SQL injection.2. Performance may be affected: Each SQL statement requires overhead such as [Statement Analysis]

[SQL]-- ============================= [Create a stored procedure] ====================== ======USE [Message]GO/***** Object: StoredProcedure [dbo]. [read external database query] Script Date: 10/24/2012 05:39:16 ******/SET ANSI_NULLS ONGOSET