Oracle PL/SQL:CREATE TABLE statement: create a table with primary key.CREATE TABLE statement can be used to create table objects in database. 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 ...
createtableDepartment-( --创建部门编号;int代表整数类型;primary key代表主键;identity(1,1)代表从1开始步长为1自增长; DepartmentIdintprimarykeyidentity(1,1), --创建部门名称;nvarchar(50)代表长度50的字符串;not null代表不能为空; DepartmentName nvarchar(50)notnull, --创建部门描述;text代表长文本; Dep...
1.创建表时同时创建主键(加primary key) Create Table Book ( ID int identity(1,1) primary key, Name nvarchar(50) not null, StudentID int not null ) 1. 2. 3. 4. 5. 6. 2.用SQL语句单独创建主键 1)创建主键同时会自动在该主键上创建聚集索引 语句:alter table [表名] add constraint PK_Bo...
CREATE TABLE命令是特权操作。用户必须具有%CREATE_TABLE管理权限才能执行CREATE TABLE。否则将导致SQLCODE –99 %msg User 'name' does not have %CREATE_TABLEprivileges。如果拥有适当的授予权限,则可以使用GRANT命令将%CREATE_TABLE权限分配给用户或角色。管理权限是特定于命名空间的。 默认情况下,将强制执行CREATE TA...
[ WITH ( <table_option> [ ,... n ] ) ] [ ; ] <column_definition> ::= column_name <data_type> [ FILESTREAM ] [ COLLATE collation_name ] [ SPARSE ] [ MASKED WITH ( FUNCTION = 'mask_function' ) ] [ [ CONSTRAINT constraint_name ] DEFAULT constant_expression ] [ IDENTITY [ (...
CREATE TABLE Orders ( OrderID INT UNIQUE NOT NULL, OrderItem VARCHAR, OrderQuantity INT, CustomerNum INT, CONSTRAINT OrdersPK PRIMARY KEY (OrderID), CONSTRAINT CustomersFK FOREIGN KEY (CustomerNum) REFERENCES Customers (CustID) ) 最常见的情况是,外键引用另一个表的主键字段。但是,外键可以引用RowID...
[ WITH ( <table_option> [ ,... n ] ) ] [ ; ] <column_definition> ::= column_name <data_type> [ FILESTREAM ] [ COLLATE collation_name ] [ SPARSE ] [ MASKED WITH ( FUNCTION = 'mask_function' ) ] [ [ CONSTRAINT constraint_name ] DEFAULT constant_e...
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
USE AdventureWorks2022; GO IF OBJECT_ID('HumanResources.EmployeeOrg') IS NOT NULL DROP TABLE HumanResources.EmployeeOrg CREATE TABLE HumanResources.EmployeeOrg ( OrgNode HIERARCHYID PRIMARY KEY CLUSTERED, OrgLevel AS OrgNode.GetLevel(), EmployeeID INT UNIQUE NOT NULL, EmpName VARCHAR(20) NOT NUL...