It is possible to add constraints like primary key ,foreign key while table creation.Primary key is the unique identifier for a row of data.One table cannot contain duplicate primary key values.Primary key also can be a combination of columns (COMPOSITE Primary Key))....
Is there a way to create a primary key from multiple columns in SQL Server Express (e.g. First Name plus Last Name)All replies (3)Wednesday, November 11, 2009 7:13 PM ✅Answered | 1 voteHi Please check the below 複製 CREATE TABLE table1( ClassID int, StudentID int, location ...
( logical_expression ) ] <column_set_definition> ::= column_set_name XML COLUMN_SET FOR ALL_SPARSE_COLUMNS <table_constraint> ::= [ CONSTRAINT constraint_name ] { { PRIMARY KEY | UNIQUE } [ CLUSTERED | NONCLUSTERED ] ( column_name [ ASC | DESC ] [ ,... n ] ) [ WITH ...
( logical_expression ) ] <column_set_definition> ::= column_set_name XML COLUMN_SET FOR ALL_SPARSE_COLUMNS <table_constraint> ::= [ CONSTRAINT constraint_name ] { { PRIMARY KEY | UNIQUE } [ CLUSTERED | NONCLUSTERED ] ( column_name [ ASC | DESC ] [ ,... n ] ) [ WITH ...
题目使用下列SQL语句创建教师表: CREATE TABLE 教师表(教师编号 I PRIMARY KEY,; 姓名 C(8) NOT NULL,; 职称 C(10) DEFAULT "讲师") 如果要删除“职称”字段的DEFAULT约束,正确的SQL语句是___。相关知识点: 试题来源: 解析 A 反馈 收藏
如果学生表STUDENT是使用下面的SQL语句创建的: Create table student(SNO C(4)) PRIMARY KEY Not Null; S
CREATE TABLE statementThe CREATE TABLE statement defines a table. The definition must include its name and the names and attributes of its columns. The definition can include other attributes of the table, such as its primary key and its table space. Invocation for CREATE TABLE This statement ...
error occurs if you try to add a new row with a key value that matches an existing row. If you specify a prefix value for a column in a UNIQUE index, the column values must be unique within the prefix length. A UNIQUE index permits multiple NULL values for columns that can contain ...
CREATEDATABASEdatabase_name[CONTAINMENT= {NONE|PARTIAL} ] [ON[PRIMARY]<filespec>[ ,...n ] [ ,<filegroup>[ ,...n ] ] [LOGON<filespec>[ ,...n ] ] ] [COLLATEcollation_name] [WITH<option>[,...n ] ] [;]<option>::={FILESTREAM(<filestream_option>[,...n ] ) |DEFAULT_FULLTE...
USEAdventureWorks2022; GO IF OBJECT_ID('HumanResources.EmployeeOrg') IS NOT NULLDROPTABLEHumanResources.EmployeeOrgCREATETABLEHumanResources.EmployeeOrg ( OrgNode HIERARCHYID PRIMARYKEYCLUSTERED, OrgLevelASOrgNode.GetLevel(), EmployeeIDINTUNIQUENOTNULL, EmpNameVARCHAR(20)NOTNULL, TitleVARCHAR(20)NULL);...