SQL Alter Table Primary Key
Alter a Table Primary Key in SQL modifies the existing table and adds a
primary key.
Create Table Stu_Table
SQL statement to create table:
create table Stu_Table(Stu_Id varchar(2), Stu_Name varchar(15), Stu_Class varchar(10))
|
Insert data into Stu_Table
SQL statement to insert data into table:
insert into Stu_Table values(1,'Komal',10);
insert into Stu_Table values(2,'Ajay',10);
insert into Stu_Table values(3,'Rakesh',10);
insert into Stu_Table values(4,'Bhanu',10);
insert into Stu_Table values(5,'Santosh',10);
insert into Stu_Table values(6,'Tanuj',10);
|
Stu_Table
Records in the table:
| Stu_Id |
Stu_Name |
Stu_Class |
| 1 |
Komal |
10 |
| 2 |
Ajay |
10 |
| 3 |
Rakesh |
10 |
| 4 |
Bhanu |
10 |
| 5 |
Santosh |
10 |
| 6 |
Tanuj |
10 |
Describe Stu_Table
+-----------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-----------+-------------+------+-----+---------+-------+
| Stu_Id | varchar(2) | NO | | | |
| Stu_Name | varchar(15) | YES | | | |
| stu_class | varchar(10) | NO | | | |
+-----------+-------------+------+-----+---------+-------+
|
Alter Table Primary Key
Syntax
The table_name is the name of the table on which
primary key is added.
The column_name is the name of the column
on which primary key is created.
ALTER TABLE table_name
ADD PRIMARY KEY (column_name)
|
Alter Table Primary Key
Query
The given Query show you an example to alter a
table name 'Stu_Table' on which primary key is added. The 'Stu_Id' is the
name of the column on which primary key is created.
ALTER TABLE Stu_Table
ADD PRIMARY KEY (Stu_Id)
|
Describe Stu_Table
+-----------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-----------+-------------+------+-----+---------+-------+
| Stu_Id | varchar(2) | NO | PRI | | |
| Stu_Name | varchar(15) | YES | | | |
| stu_class | varchar(10) | NO | | | |
+-----------+-------------+------+-----+---------+-------+
|
|
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