–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(‘
CREATETABLE[database_name.[owner].]table_name (<columnname><data type>[[DEFAULT <constant expression>] | [IDENTITY [(seed,increment) [NOT FOR REPLICATION]]] [ROWGUIDCOL] [COLLATE <collation name>] [NULL|NOT NULL]--是否允许为空[<column constraints>]--列约束| [column_name AS compute_col...
CREATETABLE[database_name.[owner].]table_name ( <columnname><data type> [[DEFAULT <constant expression>]|[IDENTITY [(seed, increment) [NOT FOR REPLICATION]]] [ROWGUIDCOL] [COLLATE <collation name>] {[NULL|NOT NULL]|[PRIMARY KEY | UNIQUE]} [FOREIGN KEY ( column [ , n])REFERENCESref...
CREATE the table with one column. Execute the following statements in order to create your copy of the original table, but just one column to start with. 创建一个只有一列的表。执行下面的语句以创建你的源表的副本,但是最初只有一列。 SQLUSE TSQL2012; GO CREATE TABLE Production.CategoriesTest ...
create table testidentity( 42 id int identity, 43 words varchar(10)) 44 45 insert into testidentity values('a') --标识列不指定 46 insert into testidentity values('b') --指定除了标识列外的列 47 48 set IDENTITY_INSERT testidentity on 49 insert into testidentity(id,words) values(10,'c...
The following example creates a table with an identity column and shows how the SET IDENTITY_INSERT setting can be used to fill a gap in the identity values caused by a DELETE statement. SQL Copy USE AdventureWorks2022; GO Create tool table. SQL Copy...
-- Create a new table.CREATETABLE{database_name.schema_name.table_name|schema_name.table_name|table_name} ( {column_name<data_type>[<column_options>] } [ ,...n ] ) [WITH(<table_option>[ ,...n ] ) ] [;]<column_options>::=[COLLATEWindows_collation_name] [NULL|NOTNULL]-- de...
在这个表中,categoryid是主键,在CREATE TABLE语句末尾添加的CONSTRAINT子句告诉你它是一个主键。这个约束的名称是PK_Categories,你可以指定其它名称。 Another way of declaring a column as a primary key is to use the ALTER TABLE statement, which you could write as follows. ...
CREATETABLE[dbo].[TableWithWarning] ( [ID]INTNOTNULLIDENTITY(0,1), [c1]INTNOTNULLPRIMARYKEY, [c2]INT, [c3]INT, [SmallString]VARCHAR(2) )ON[PRIMARY]CREATETABLE[dbo].[FixedTable] ( [ID]INTNOTNULLIDENTITY(0,1), [c1]INTNOTNULLPRIMARYKEY, [c2]INT, [c3]INT, [SmallString]CHAR(2) ...
create table outtable ( id int not null primary key, [name] nvarchar(4) not null, adrress nvarchar(20) default '地址不详' ) truncate table outtable alter table outtable alter column id int identity(4,1) insert outtable values (1,22,'') ...