syntaxsql Copy ALTER TABLE { database_name.schema_name.table_name | schema_name.table_name | table_name } { ALTER COLUMN column_name { [ type_schema_name. ] type_name [ ( { precision [ , scale ] | max | xml_schema_collection } ) ] [ COLLATE collation_name ] [ NULL | NOT ...
To determine the current compatibility level, query thecompatibility_levelcolumn ofsys.databases. SQL SELECTname, compatibility_levelFROMsys.databases; To determine the version of the Database Engine that you're connected to, execute the following query. ...
ALTERTABLEtable_name ADDcolumn_name datatype; The following SQL adds an "Email" column to the "Customers" table: ExampleGet your own SQL Server ALTERTABLECustomers ADDEmail varchar(255); ALTER TABLE - DROP COLUMN To delete a column in a table, use the following syntax (notice that some da...
适用于: SQL Server Azure SQL 数据库 Azure SQL 托管实例在SQL Server 中更改全文检索的属性。Transact-SQL 语法约定语法syntaxsql 复制 ALTER FULLTEXT INDEX ON table_name { ENABLE | DISABLE | SET CHANGE_TRACKING [ = ] { MANUAL | AUTO | OFF } | ADD ( column_name [ TYPE COLUMN type_column...
使用双向赋值(如UPDATE T1 SET @v = column_name = <expression>)来更新列会产生意外后果,因为在语句执行过程中,可以在其他子句(如WHERE和ON子句)中使用变量的实时值,而不是使用语句起始值。 这会导致谓词的含义无法预测地逐行变化。 只有在兼容性级别设置为 90 时,此行为才适用。使用双向赋值来更新列会产生预...
Transact-SQL 语法约定语法SQL Server、Azure SQL 数据库和Azure SQL 托管实例的语法。syntaxsql 复制 ALTER INDEX { index_name | ALL } ON { REBUILD { [ PARTITION = ALL [ WITH ( <rebuild_index_option> [ , ...n ] ) ] ] | [ PARTITION = partition_number [ WITH ( <single_partition_...
Column or parameter names within an object Index names within a table Duplicate names resulting from the new collation cause the change action to fail, and SQL Server returns an error message specifying the namespace where the duplicate was found. ...
更改column_name 列的说明。 comment 必须是 STRING 文本。 FIRST 或AFTER 标识符 将列从当前位置移到前面(FIRST)或立即移动到 identifier 之后(AFTER)。只有 table_name 为Delta 表时才支持此子句。 TYPEdata_type 适用于 Databricks SQL Databricks Runtime 15.2 及更高版本 更改column_name 列的...
SQL 托管实例 语法 syntaxsql ALTERDATABASEdatabase_name{<add_or_modify_files>|<add_or_modify_filegroups>}<add_or_modify_files>::={ADDFILE<filespec>[ ,...n ] [TOFILEGROUP{filegroup_name} ] |ADDLOGFILE<filespec>[ ,...n ] |REMOVEFILElogical_file_name|MODIFYFILE<filespec>}<filespec>::...
syntaxsql 复制 ALTER DATABASE { database_name | CURRENT } SET { [ ,...n ] [ WITH <termination> ] } ::= { <accelerated_database_recovery> | <auto_option> | <automatic_tuning_option> | <change_tracking_option> | <containment_option> | <cursor_option> | <database...