SQL Server

SQL Server performance optimization involves many aspects, such as good system and database design, high-quality SQL writing, appropriate data table index design, and even various hardware factors: network performance, server performance, operating

Let's start by saying that these two variables are a meaning, but their scope is different.ALTER DATABASE dbTest set ANSI_NULL_DEFAULT on; -This is scoped to the entire SQL Server database!Set set ANSI_NULL_DFLT_ON on; -The scope of this is the

SQL Server does not have a group_concat function in MySQL that can connect grouped data together.After the search on the internet, found a way to implement this function, hereby recorded.Selecta,stuff ((SELECT ', ' + b from #tb WHERE a = t.a FOR XML

Database managementTalking about database management —————— The first thing to say is database design, a good database design concept can avoid many databases caused by the trouble and the cost of late maintenance1, the first thing to consider is

To understand how the Write-ahead log works, it's important for what know how modified data are written to disk. SQL Server maintains a buffer cache into which it reads data pages then data must be retrieved. Data modifications is not made directly

About the primary key. It is very well understood that the primary function of the primary key is to identify a data is unique, that is, to ensure the entity integrity of the data. Prevent data duplication. But foreign key words have a lot of

The entity (entities) Contact (relationships) model abbreviation E-R model is also called the E-r method, which was first proposed by P.p.chen in 1976. There is also a key element of the Attributes-property, which provides a user-oriented expression

Database objects are part of a database, and data tables, views, indexes, stored procedures, and triggers are all database objects.The primary object of a database is a data table, which is a collection of two-dimensional arrays for storing various

C # code backs up the database and does not require additional DLLsprotected void Button1_Click (object sender, EventArgs e){///Backup method///SqlConnection conn = new SqlConnection ("server=.; DATABASE=AAAA; User Id=sa; Password=sa; ");SqlCommand

SELECT * from Information_schema.columns WHERE table_name= ' account 'SELECT(Case time A.colorder=1 then d.name Else ' end) as table name,--returns null if the table name is the sameA.colorder as Field ordinal,A.name as field name,(Case is

1. Re-compiling related to correctness1. To add columns to a table or view, delete the columns.2. Add constraints, defaults, rules, delete constraints, default values, and rules for the table.3. Add an index to the table or view.4. If you plan to

Installation of SQL20081, double-click Open Setup Setup file2. Click "New Installation or add features to an existing installation" 3, Setup support rules, after installation, click OK 4. Enter the key for the product and click Next

CREATE TABLE Document (ID int NOT NULL,Name nvarchar (255) is not NULL,Body nvarchar (max) not NULL);GoCreate unique index uq_ix_for_document--#这里一定要加一个not The null unique index is used below. Without this, you cannot add a full-text index. On

The first step:Find the first page of the table DBCC IND (DB_NAME,TABLE_NAME,-1);ExampleDBCC IND (STUDIO,PERSON,-1); # Pagefid is the file number pagepid the page number.Step Two:View pages,DBCC TRACEON (3604)# does not open this DBCC page

In the previous article, the memory management of SQL Server resource management (above), introduced some theoretical knowledge of SQL Server memory management, this article uses this knowledge to solve some common problems in the real world.First,

1, the database is broken down into a logical page, each page 8K, in each file page from 0--x continuous numbering;2, can be [database_id] [file_id] [page_id] in the form of reference page;3, ALTER DATABASE expands the file at the end of the file to

The first step:Create DATABASE StudioOn primary(name = ' Studio ', filename= ' E:\DB\Studio.mdf ', SIZE=10MB),Filegroup FG2(name = ' Studio_fg2 ', filename= ' E:\DB\Studio_FG2.ndf ', SIZE=10MB)Log on(name = ' Studio_log ', filename= '

SQL Server extracts numbers, English and Chinese SQL statements, serversql -- SQL checks whether the field value has the Chinese create function fun_getCN (@ str nvarchar (4000) returns nvarchar (4000) as begin declare @ word nchar (1), @ CN

SQLSERVERAGENT warning: Event ID: 312, sqlserveragent312 Successfully re-opened the local eventlog-NOTE: Some events may have been missed. Attempting to re-open the local eventlog... Unable to read local eventlog (reason: the event log file has been

Sql2000 error Successfully re-opened the local eventlog solution, re-openedeventlog Error 1: Unable to read local eventlog (reason: the event log file has been changed between reads.Error 2: Successfully re-opened the local eventlog-NOTE: Some