sql server create table syntax

Label:I. Definition and characteristics of the identity columnThe identity column in SQL Server is also called the identifier column, which is also known as the self-increment column.This type of column has the following three characteristics:1. The data type of the column is a numeric type without decimals2, when inserting (insert) operation, the value of the column is generated by the system according to

corresponding if-else if syntax1) C #If (expression 1) {result 1;}else if (expression 2) {result 2;}else {default result;}2) SQL ServerCaseWhen expression 1 then display 1When expression 2 then display 2else default displayEnd3 For example, if we have sex in the database is identified with the f,m, now we want to use the male and female identity, the SQL statement is as follows: Copy Code code as

verification and data unbinding logic. (3) create a series of independent SQL statements for the modification of multi-row data. Like those generated when the update method is called in a sqldataadapter, these updates can be submitted independently or in batches to the server. However, although multiple statements are contained in batch submission, these stateme

I. you need to analyze and query the number of students and passing students of each course in each class. You need to display the query results in the same table, including the class, course number, number of students and number of passing students. implementation steps -- 1. create a temporary table # Number of Students createtable # Number of students (class c

Using a regular expression, the SQL Server database supports the location parameter syntax !, Sqlserver . In. NET Framework 2.0, Microsoft. data. the Common namespace defines a set of classes for programmers to write data access code for different databases, and provides a standard demonstration in the Enterprise Library. However, a major problem is that when pro

Tags: Service status Related Information script database state information Snapshot representationIn SQL Server replication (Replication), it is possible that the need for a new table or some tables to an existing replication (publish subscription) may occur due to changes in business requirements, which should be normal and common. However, in the existing repli

Tags: div Select server data log row data exists in BSP spanInserting multiple rows of data, having more than one piece of data in the original table, and building a new table can be cumbersome, using the following syntax:Add data from an existing table to a table that alrea

SQL Server data table field custom Custom Data Format method, SQL Server This document describes how to customize the Custom Data Format of SQL Server data

Tags: SQL Server 2008 Database Foundation650) this.width=650; "Src=" https://s5.51cto.com/wyfs02/M01/9D/F1/wKioL1mJJluAaymtAACLAyeMKZs073.png-wh_500x0-wm_ 3-wmp_4-s_231760325.png "style=" Float:none; "title=" 2017-08-08_10-33-20.png "alt=" Wkiol1mjjluaaymtaaclayemkzs073.png-wh_50 "/>650) this.width=650; "Src=" https://s5.51cto.com/wyfs02/M02/9D/F1/wKiom1mJJluQtS21AABpHBXe2E0745.png-wh_500x0-wm_ 3-wmp_4-s_38

Tags: modify alt nbsp Col Hyper Perl Big entity statement1. Create a table Create TableWorkitemhyperlink (IDbigint Primary Key,--PRIMARY KeyWorkitemidbigint Identity(1,1) not NULL,--where the identity (a) represents a self-increment, the first 1 represents counting from 1, the second 1 represents each increase of 1. HyperLinkvarchar(Max) not NULL, Commentvarchar(

--Data manipulation SELECT-Retrieving data rows and columns from database tables INSERT-Adding new data rows to a database table Delete-deleting data rows from a database table UPDATE- Update data in a database table --Data definition CREATE table--

Label:1. Createdatabase table-which database to use, if you do not write this sentence is the default database, you can also use the mouse to select the current database using TestDB--CREATE TABLE TableName (--id represents the field name NT data type--primary key primary key--not null non-null--identity (All) initial value is 1 per self-growth 1 ID int primary k

1. Create a database table --which database to use, if you do not write this is the default database, you can also use the mouse to select the current database using testdb -Create a table tablename ( --id represents the field name --int data type --primary key primary --not null --ide

A) Easy to type, update efficiency:Update table1Set Field1=table2.field1,field2=table2.field2From Table2 where table1.id=table2.idb) Conventional way, this is equivalent to a left join, in the outside where is the number of updates, if not add where is all recordsUpdate table1 Set field1=(select top 1 field1 from table2 where table2.id=table1.id)where table1.id in (condition)SQL Server Update

To determine if a table does not exist, create a table:if exists (SELECT * from dbo.sysobjects WHERE id = object_id (N ' [dbo].[ TableName] ') and OBJECTPROPERTY (ID, N ' isusertable ') = 1)BeginCREATE TABLE [dbo]. [TableName] ([FID] [INT] Not NULL,[FCode] [varchar] (255) COLLATE chinese_prc_ci_as NULL,[FName] [varchar] (255) COLLATE chinese_prc_ci_as NULL,[Fpare

variables, such as @ @error represents the error number of the most recent T-SQL statement. Of course, because a table variable is a variable first, it can only survive in one batch, which is what we call the boundary, beyond which the table variable dies. table variables are stored in memory, and it is precisely beca

Oracle database The process of creating temporary tables and the contrast with the different points of the SQL Server Temp table is the main content of this article, let's take a look at this part of the content, we hope to be able to help you. 1. Introduction In addition to saving permanent tables, Oracle databases can also

-- Data OperationsSELECT -- retrieve data rows and columns from database tablesINSERT -- add new data rows to the database tableDELETE -- DELETE data rows from a database tableUPDATE -- UPDATE data in the database table-- Data DefinitionCreate table -- CREATE a database TABLEDrop table -- delete a

SQL Server insert efficiency (heap table vs clustered index table) "Which of the following is more efficient for SQL Server insert operations in heap tables or clustered index tables? Why is it high ?" Some colleagues have aske

SQL server determines whether a database, table, column, or view exists. SQL server 1. Determine whether the database exists If exists (select * from sys. databases where name = 'database name ')Drop database [database name] 2. Check whether the