SQL Server

Transferred from: http://www.cnblogs.com/jiajiayuan/archive/2011/06/16/2082488.htmlFor example, all of the following are examples of studnet tables:Calculating string LengthsLen () is used to calculate the length of a stringSelect Sname, Len (sname)

There is a priority problem in the data type in SQL Server. The return result type of a scalar expression is also determined by the type of operand, such as 1 + ' 1 ' =2. Instead of ' 11 ', the precedence of some int is higher than that of the

The sql_variant type is used to store various data types that are supported in SQL Server.For sql_variant comparisons, the SQL Server data type hierarchy sequence is divided into multiple data type systems, and thesql_variant data type is at the top

Today, I met a very interesting thing that I had not noticed before, so write it down.Let's look at examples first.SETAnsi_nulls onGOSETQuoted_identifier onGO CREATE PROCEDUREgetorderbeforedays@BeforDays INT asBEGIN IF @BeforDays 0 BEGIN

First look at the SQL statement belowCREATE TABLE #DateTest (Id INT,Sampledate DATETIME)INSERT into #DateTest VALUES (1, ' 1 Jan 2010 10:30 ')INSERT into #DateTest VALUES (2, ' 2 Jan 2010 23:59 ')INSERT into #DateTest VALUES (3, ' 3 Jan 2010 12:34 ')

Original address: Http://msdn.microsoft.com/zh-cn/library/ms190969.aspxThe basic unit of data storage in SQL Server is the page. The disk space allocated for the data file (. mdf or. ndf) in the database can be logically divided into pages (numbered

The statements in T-SQL that are used to write process Control modules are: BEGIN ... and statement, IF ... Else statements, case statements, while statements, goto statements, break statements, WAITFOR statements, and return statements.1. BEGIN ...

SQL column Career2011-04-22 16:13:41 Good thing, turn around, hey. * Normal row and column conversion (Aixinjueluo. Yuk Wah 2007-11-18 in Sanya, Hainan) A Student score table (TB) is provided as follows: Name Subject result Zhang San language 74

Error message: Change to log on SA failed ...With the impression that it takes two steps to enable, the login mode in the server properties is changed to SQL Server and Windows mode first.The second step of the server login name in the right-click

When talking about database performance optimizations, it is common to refer to "indexes", but many people do not really understand the index, nor do they know why the index can speed up the retrieval so that the index is not applied well in

Aliases cannot be used for tables in update statements in SQL ServerEg:update Table A set a.column= "" where ...This is not true in SQL Server (it can be in Oracle), and you can't use aliases for tables. This is because the UPDATE statement we've

Original: Method of emptying all table data in a SQL Server databaseIn fact, the method of deleting the data in the database is not complicated, why do I have to superfluous, one is that I am here to delete all the data from the database, because

1. SQL Server Data Archiving Scheme2. SQL Server High-availability scenarios3. SQLIO simulate random or sequential ways to test disk IO performance4. SQLIOSim Simulation of SQL Server behavior to test IO performance5. Capture and store SQL Server

Background:New servers that require increased performance monitoring to find that performance metrics cannot be read through PowerShellWorkaround: Open the Registry Editor by going to the Start Menu and selecting Run ..., then type

What is a trigger?　　In SQL Server is a certain operation on a table, triggering a certain condition, thus executing a program. A trigger is a special stored procedure that cannot be called explicitly, but is automatically activated when a record is

How to change the collation of SQL SERVER 2000Alter Datebase ALTER DATEBASE database Chinese_prc_binALTER TABLE TBALTER COLUMN colname nvarchar (+) COLLATE chinese_prc_ci_as--Case insensitiveALTER TABLE TBALTER COLUMN colname nvarchar (+) COLLATE

Why do I need triggers (TRIGGER? )? The typical application is that the bank's ATM system assumes that the system's database design requires two tables: The Account Information Table (Bank) holds the account information, and the Transaction

1. Introduction to Partitioned TablesA partitioned table is logically a table and physically multiple tables. From the user's point of view, the partition table and the normal table are the same. The primary purpose of using partitioned tables is to

How to ignore index hints in SQL ServerWhen we want a query statement to take advantage of an index, we typically add index hints in the query statement, like thisSELECT from TB with (indexwhere balIn a production environment, because of this

SQL Server 5030 Error ResolutionToday when using SQL Server, because the database was previously created forgot to set collocation, the database inserted Chinese characters are garbled, so into the options of the databases to modify collocation, the