SQL

sql change column types

ALTER TABLE table_name
ALTER COLUMN column_name datatype;

-- Example
ALTER TABLE product
ALTER COLUMN description VARCHAR(250);

sql server alter column

ALTER TABLE table_name 
ALTER COLUMN column_name new_data_type(size);

SQL Modify Column in a Table

#SQL Server

ALTER TABLE Customers
ALTER COLUMN age VARCHAR(2);

#MySQL

ALTER TABLE Customers
MODIFY COLUMN age VARCHAR(2);

#Oracle

ALTER TABLE Customers
MODIFY age VARCHAR(2);

#PostgreSQL

ALTER TABLE Customers
ALTER COLUMN age TYPE VARCHAR(2);

alter table query sql server change column

ALTER TABLE employees
  ALTER COLUMN last_name VARCHAR(75) NOT NULL;

alter table query sql server change column

ALTER TABLE table_name
  ALTER COLUMN column_name column_type;

SQL Modify Column in a Table -SQL Server

ALTER TABLE Customers
ALTER COLUMN age VARCHAR(2);

alter table query sql server change column

sp_rename 'employees.last_name', 'lname', 'COLUMN';

alter table query sql server change column

sp_rename 'table_name.old_column_name', 'new_column_name', 'COLUMN';

alter table query sql server change column

ALTER TABLE table_name
  DROP COLUMN column_name;