SQL - Alter Table Statement
SQL ALTER TABLE is used to add, rename, modify or drop columns
RENAME A TABLE:
Syntax:
RENAME TABLE Existing_TableName TableName TO New_TableName
Example:
RENAME TABLE Employee TO Student
TO ADD A COLUMN:
Syntax:
ALTER TABLE TableName ADD ColumnName data_type;
Example:
ALTER TABLE Employee ADD Address VARCHAR(255);
Modify a column
Syntax:
ALTER TABLE TableName MODIFY ColumnName column_type;
Example:
ALTER TABLE Employee MODIFY EmployeeID int NOT NULL;
DROP A COLUMN:
Syntax:
ALTER TABLE TableName DROP COLUMN ColumnName;
Example:
ALTER TABLE Employee DROP COLUMN Address;
RENAME A COLUMN:
Syntax:
ALTER TABLE TableName  RENAME COLUMN Old_Name to New_Name;
Example:
ALTER TABLE Employee  RENAME COLUMN Address to Permanent_ADDRESS;