The difference between ALTER and UPDATE commands in SQL

In this article, we will understand the difference between ALTER command and UPDATE

command in SQL.

ALTER command

• This command is data definition language (DDL).

• It performs operations on the structure level, not the data level.

• This command is used to add, delete and modify table attributes in the database.

• This command initializes the values ​​of all values ​​in the tuple to NULL by default.

• It changes the structure of the table.

Syntax: Add column−

ALTER TABLE table_name ADD column_name datatype;

Delete a column

ALTER TABLE table_name DROP COLUMN column_name;

UPDATE command

• This command is A data manipulation language (DML).

• It performs data level operations.

• It updates existing records in the database.

• It is using tuples of UPDATE commands.

• It changes the data within the table.

Grammar:

UPDATE table_name
SET column1 = value1, column2 = value2....columnN=valueN
[ WHERE CONDITION ];

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