在Oracle数据库中,可以使用ALTER TABLE语句为已存在的表添加主键。语法如下: sql ALTER TABLE 表名ADD CONSTRAINT 主键名 PRIMARY KEY (列名1, 列名2, ...); 如果不需要命名主键,可以直接使用: sql ALTER TABLE 表名ADD PRIMARY KEY (列名1, 列名2, ...); 3. 提供一个示例,展
1.语法:ALTER TABLE 表名 ADD CONSTRAINT 主键名 PRIMARY KEY 表名(主键字段); 3.添加外键 1.语法:ALTER TABLE 表名 ADD CONNSTRAINT 外键名 FOREIGN KEY(外键字段) REFERENCES 关联表名(关联字段); 4.插入单(多)条数据记录(和SQL Server相同,但是不能用select多列添加数据) 1.INSERT INTO 表名[(字段名...
Now, let us solve the above issues one by one by updating our tables using relevant SQL queries. Define [country_id] as the Primary Key on [tb_country], ALTER TABLE [tb_country] ADD CONSTRAINT [PK_tb_country] PRIMARY KEY CLUSTERED ( [country_id] ASC )WITH (PAD_INDEX = OFF, STATI...
[cc lang=”sql”] ALTER TABLE dbo.Person ADD CONSTRAINT PK_Person PRIMARY KEY CLUSTERED (PersonID, DOB); [/cc]For an existing table, there are two places that can be used to specify the primary key. The first is inline to the column. Using this method, you cannot create a composite...
Alter syntax and example. Syntax ALTER TABLE tabel_name ADD PRIMARY KEY (column_name); Create table CREATE TABLE users( userid numeric, username varchar(100), userpass varchar(250), usermail varchar(50) ); Example Add primary key ALTER TABLE users ADD PRIMARY KEY (userid);...
Suppose we want to add a primary key to thestudent_idcolumn. We can use the following SQL statement: ALTERTABLEstudentsADDPRIMARYKEY(student_id); 1. 2. After executing this statement, thestudentstable will have a primary key on thestudent_idcolumn. The modified table will look like this: ...
obclient [test]> alter table t1 add primary key(id); ERROR 1235 (0A000): Not supported feature or function # 参考OB手册,用modify和change语法也失败 obclient [test]> alter table t1 modify id int primary key; ERROR 1235 (0A000): Not supported feature or function ...
SQLコピー -- Add a primary key>CREATETABLEpersons(first_nameSTRINGNOTNULL, last_nameSTRINGNOTNULL, nicknameSTRING); >ALTERTABLEpersonsADDCONSTRAINTpersons_pk PRIMARYKEY(first_name, last_name);-- Add a foreign key>CREATETABLEpets(nameSTRING, owner_first_nameSTRING, owner_last_nameSTRING)...
该sp_addlinkedserver语句需要ALTER ANY LINKED SERVER权限。 (SQL Server Management Studio以需要 sysadmin固定服务器角色成员身份的方式实现新的链接服务器对话框。 示例 A. 使用 Microsoft SQL Server OLE DB 提供程序 下面的示例将创建一个名为SEATTLESales的链接服务器。 产品名称为SQL Server,未使用访...
ALTER COLUMN Product_Price DECIMAL(10, 2); Strengthening Data Integrity: Adding Constraints Suppose an “Employees” table requires a foreign key relationship with a “Departments” table. You can establish it usingALTER. ALTER TABLE Employees ADD CONSTRAINT FK...