In SQL, theALTER TABLEcommand is used to modify the structure of an existing table like adding, deleting, renaming columns, etc. Example -- add phone column to Customers tableALTERTABLECustomersADDphonevarchar(10); Run Code Here, the SQL command adds a column namedphoneto theCustomerstable. A...
For example, ALTER LOGIN [<domain>\<group>] DISABLE returns the following error message: Output Copy "Msg 15151, Level 16, State 1, Line 1 Cannot alter the login '*Domain\Group*', because it doesn't exist or you don't have permission. This is by design. In SQL Database, login...
默认值为OFF“超大规模”Azure SQL 数据库除外。 对于“超大规模”中的所有索引生成作,除非使用可恢复索引生成,否则始终 ONSORT_IN_TEMPDB。 对于可恢复索引生成,SORT_IN_TEMPDB 始终OFF。 ON 用于生成索引的中间排序结果存储在其中 tempdb。 这可以减少创建索引所需的时间。 但是,这会增加索引生成期间所使用的磁盘...
CREATE TABLE dbo.doc_exc (column_a INT NOT NULL CONSTRAINT my_constraint UNIQUE) ; GO -- Example 1. Remove a single constraint. ALTER TABLE dbo.doc_exc DROP my_constraint ; GO DROP TABLE dbo.doc_exc; GO CREATE TABLE dbo.doc_exc ( column_a INT NOT NULL CONSTRAINT my_constraint UNIQUE...
Example ALTERTABLECustomers DROPCOLUMNEmail; ALTER TABLE - RENAME COLUMN To rename a column in a table, use the following syntax: ALTERTABLEtable_name RENAMECOLUMNold_nametonew_name; To rename a column in a table in SQL Server, use the following syntax: ...
For example, the following statements are not allowed: ALTER TABLE t1 DROP COLUMN f1 DROP (f2); ALTER TABLE t1 DROP COLUMN f1 SET UNUSED (f2); ALTER TABLE t1 DROP (f1) ADD (f2 NUMBER); ALTER TABLE t1 SET UNUSED (f3) ADD (CONSTRAINT ck1 CHECK (f2 > 0)); You can drop an ...
Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance Azure Synapse Analytics Analytics Platform System (PDW) SQL database in Microsoft Fabric Modifies an existing table or view index (rowstore, columnstore, or XML) by disabling, rebuilding, or reorganizing the index; or by ...
Reimport the CLOB and SQL NCHAR columns. Restrictions: You must have SYSDBA system privilege, and you must start up the database in restricted mode (for example, with the SQL*Plus STARTUP RESTRICT command). The current character set must be a strict subset of the character set to whic...
Transact-SQL-Referenz (T-SQL) Transact-SQL-Referenz (T-SQL) Datum und Uhrzeit hierarchyid-Methoden (Datenbank-Engine) Numerisch Zeichenfolge und Binär Räumliche Geografie und Instanzen (geografische Datentypen) Räumliche Geometrie und Instanzen (Geometrie-Datentyp) Datentypen XML DBCC Funkt...
Discontinuedfunctionality introduced in a given SQL Server version isnotprotected by compatibility level. This refers to functionality that was removed from the SQL Server Database Engine. For example, theFASTFIRSTROWhint was discontinued in SQL Server 2012 (11.x) and replaced with theOPTION (FAST...