CHECK Constraint in Existing Table We can add theCHECKconstraint to an existing table by using theALTER TABLEclause. For example, let's add theCHECKconstraint to theamountcolumn of an existingOrderstable. -- add
若要将 check 约束添加到 Delta Lake 表,请在创建表后使用ALTER TABLE。 语法 使用table_constraint子句定义跨多个列的约束或将语法与列定义分开。 复制 table_constraint { [ CONSTRAINT name ] { PRIMARY KEY ( key_column [ TIMESERIES ] [, ...] ) [ constraint_option [...] ] | { FOREIGN KEY ...
First, create the constraint. SQL Copy ALTER TABLE dbo.DocExc ADD ColumnD INT NULL CONSTRAINT CHK_ColumnD_DocExc CHECK ( ColumnD > 10 AND ColumnD < 50 ); GO To test the constraint, first add values that pass the check constraint. SQL Copy INSERT INTO dbo.DocExc (ColumnD) VALUES...
SomeIntintnotnull); go-- Consider using bulk loading techniques to speed it upALTERTABLEtable1ADD[HashValue]AS(CONVERT([tinyint],abs([TransactionID])%(32))) PERSISTEDNOTNULLaltertabletable1addconstraintpk_table1 primarykeyclustered (HashValue, TransactionID, UserID); go 选项:使用 G...
{ CHECK | NOCHECK } ] | ADD { <column_definition> | <computed_column_definition> | | <column_set_definition> } [ ,...n ] | [ system_start_time_column_name datetime2 GENERATED ALWAYS AS ROW START [ HIDDEN ] [ NOT NULL ] [ CONSTRAINT constraint_name ] DEFAULT constant_expression ...
Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance Specifies the properties of a PRIMARY KEY, FOREIGN KEY, UNIQUE, or CHECK constraint that is part of a new column definition added to a table by using ALTER TABLE. Napomena For Microsoft Fabric, visit ALTER TABLE column_...
ALTERTABLE表名ADDCONSTRAINT约束名DEFAULT 默认值FOR 列名 Adding a new column with default value, to an existing table: alter tableStudent addName nvarchar(20)not null constraintDF_Student_Name default'gester' Syntax: ALTERTABLE表名ADD列名 数据类型 是否允许nullCONSTRAINT 约束名DEFAULT 默认值 ...
ALTER COLUMN ADD COLUMN DROP COLUMN SET TBLPROPERTIES UNSET TBLPROPERTIES 修改PREDICTIVE OPTIMIZATION 如果您使用 Unity Catalog,您必須擁有MANAGE許可權或擁有下列所有權: SET OWNER TO 執行所有其他作業需要具有資料表的所有權。 重新命名 COLUMN ADD CONSTRAINT ...
其中表约束table_constraint为: [ CONSTRAINT constraint_name ] { CHECK ( expression ) | UNIQUE ( column_name [, ... ] ) index_parameters | PRIMARYKEY( column_name [, ... ] )index_parameters | PARTIAL CLUSTERKEY( column_name [, ... ] )} [ DEFERRABLE | NOT DEFERRABLE | INITIALLY DEF...
To determine the current compatibility level, query thecompatibility_levelcolumn ofsys.databases. SQL SELECT[name], compatibility_levelFROMsys.databases; To determine the version of the Database Engine that you're connected to, execute the following query. ...