In this post, we will understand the difference between the ALTER command and the UPDATE command in SQL.
This command is a Data Definition Language (DDL).
It performs operation at the structural level, not the data level.
This command is used to add, delete, and modify the attributes of the tables in a database.
This command, by default, initializes the values of all values in the tuple to NULL.
It changes the structure of the table.
Syntax: Add a column −
ALTER TABLE table_name ADD column_name datatype;
Drop a Column
ALTER TABLE table_name DROP COLUMN column_name;
This command is a Data Manipulation Language (DML).
It performs operations on the data level.
It updates the existing records in a database.
It sets the specified values in a tuple using the UPDATE command.
It changes the data inside the table.
UPDATE table_name SET column1 = value1, column2 = value2....columnN=valueN [ WHERE CONDITION ];