ALTER TABLE 语句的语法格式为: ALTERTABLEtable {[ALTER COLUMN column_name { new_data_type [ (precision[, scale]) ] [NULL | NOT NULL] |{ADD|DROP}ROWGUIDCOL } ] |ADD {[<column_definition>] |column_nameAScomputed_column_expression }[, n] |[WITH CHECK | WITH NOCHECK]ADD {<table_constraint>}[, n] |DROP {[CONSTRAINT]constraint_name |COL...
2、ALTER TABLE 具体语法: ALTERTABLEtable_name {[ALTER COLUMN <column_name> {[<schema of new data type>].<new_data_type>[(precision [,scale])]max|<xmlschemacollection>[COLLATE <collation_name>][NULL | NOT NULL]|[{ADD | DROP} ROWGUIDCOL]|PERSISTED}]|ADD<columnname><data_type>[[DEFA...
–1. IDENTIY 列不能为空,不能设默认值,创建后不能使用ALTER TABLE TableName ALTER COLUMN修改,每张表只能有一个自增列 –2. 查看当前值:SELECT IDENT_CURRENT(‘TableName’), — 查看增量值:SELECT IDENT_INCR(‘TableName’) — 查看原始种子值:SELECT IDENT_SEED(‘TableName’),起始值, TRUNCATE TABL...
Transact-SQL语言的分类如下: · 数据定义语言(Data Definition Language,DDL):用来定义和管理数据库以及数据库中的各种对象的语句,这些语句包括CREATE、ALTER和DROP等。 · 数据操纵语言(Data Manipularion Language,DML):用来查询、添加、修改和删除数据库中数据的语句,这些语句包括SELECT、INSERT、UPDATE、DELETE等。 ...
Transparent data encryption (TDE) customer-managed keys and Always Encrypted column master keys can be stored in Azure Key Vault. Eventing: event notifications, query notifications. File properties: Syntax related to database file name, placement, size, and other file properties automatically managed ...
AlterCertificateStatementKind AlterColumnAlterFullTextIndexAction AlterColumnEncryptionKeyStatement AlterCreateEndpointStatementBase AlterCreateServiceStatementBase AlterCredentialStatement AlterCryptographicProviderStatement AlterDatabaseAddFileGroupStatement AlterDatabaseAddFileStatement AlterDatabaseAuditSpec...
ALTER TABLE...ADD/DROP can add or remove a column from a memory-optimized table, or an index. CREATE INDEX and DROP INDEX cannot be run against a memory-optimized table, use ALTER TABLE ... ADD/DROP INDEX instead. For details seeAltering Memory-Optimized Tables. ...
CREATE DATABASE testdb GO USE testdb ALTER DATABASE testdb SET ALLOW_SNAPSHOT_ISOLATION ON CREATE TABLE T1 ( keycol INT NOT NULL PRIMARY KEY, datacol VARCHAR(10) NOT NULL ) INSERT INTO T1 VALUES(1, 'Version1') Issue the following code from Connection 1, which opens a transaction and...
When you use TABLESAMPLE against databases that are upgraded to SQL Server, the compatibility level of the database is set to 110 or higher, PIVOT is not allowed in a recursive common table expression (CTE) query. For more information, see ALTER DATABASE Compatibility Level (Transact-SQL).SY...
To create a table, you must provide a name for the table, and the names and data types of each column in the table. It is also a good practice to indicate whether null values are allowed in each column. To create a table, you must have the CREATE TABLE permission, and the ALTER ...