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 ...
In this recipe, I’ll demonstrate how to add aprimary key to an existing table using ALTER TABLEand ADDCONSTRAINT:ALTERTABLEPerson.EducationTypeADDCONSTRAINTPK_EducationTypePRIMARYKEY(EducationTypeID) 1.3:Creating aTable with aForeign Key Reference In this recipe, I’ll demonstrate how to create a...
添加有名称的主键约束:alter table table_name add constraint pk_name primary key (id); 删除有名称的主键约束:alter table table_name drop constraint pk_name; 6.修改表字段类型 例子:alter table student alter column birthday decimal(18, 4) not null 三、简单的sql语句(增删改查) 1.插入(insert) 向...
简介:【7月更文挑战第24天】CREATE TABLE 时的 SQL PRIMARY KEY 约束。 CREATE TABLE 时的 SQL PRIMARY KEY 约束 下面的 SQL 在 "Persons" 表创建时在 "P_Id" 列上创建 PRIMARY KEY 约束: MySQL: CREATE TABLE Persons ( P_Id int NOT NULL, LastName varchar(255) NOT NULL, FirstName varchar(255)...
你写上去的编译的时候有点小错误,正确的应该是这样写的 Create table [dbo].[adminitable]([adminpassword] [varchar](50) null,[adminname] [varchar](20) null,constraint [pk_adminitable] primary key clustered ([adminname] asc )with (pad_index=off,statistics_norecompute=off,ignore_...
第十四章 SQL命令 CREATE TABLE(一) 创建表 大纲 CREATE [GLOBAL TEMPORARY] TABLE table (table-element-commalist) [shard-key] [WITH table-option-commalist] table-element ::= [%DESCRIPTION string] [%FILE string] [{%EXTENTSIZE | %NUMROWS} integer] ...
PRIMARYKEY(id) ); In Oracle and SQL Server CREATETABLECompanies (idintNOTNULLPRIMARYKEY,namevarchar(50), addresstext, emailvarchar(50), phonevarchar(10) ); Define constraints while creating a table We can also add different types of constraints while creating a table. For example, ...
SQLTablePrimaryKeys[conn, table] returns information about the columns comprising the primary key of table.
CREATETABLEEmployees(EmployeeIDINTIDENTITY(1,1)PRIMARYKEY,FirstNameNVARCHAR(50)NOTNULL,LastNameNVARCHAR...
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 ...