How To Change Datatype Of Column In SQL?

1

Use `ALTER TABLE table_name ALTER COLUMN column_name TYPE new_data_type;` in PostgreSQL

Use `ALTER TABLE table_name MODIFY COLUMN column_name new_data_type;` in MySQL

Use `ALTER TABLE table_name ALTER COLUMN column_name new_data_type;` in SQL Server

Use `ALTER TABLE table_name ALTER COLUMN column_name TYPE new_data_type USING column_name::new_data_type;` in PostgreSQL when conversion is needed

Use `ALTER TABLE table_name MODIFY column_name new_data_type;` in Oracle

Back up the table before changing the datatype

Ensure existing data is compatible with the new datatype

Update constraints, indexes, and dependent objects if needed