What is Alter command?

Question

The ALTER command is a DDL command to modify the structure of existing tables in the database by adding, modifying, renaming, or dropping columns and constraints. You can add columns, rename columns, delete columns, or change the data type of columns using the ALTER command.

Which type of command is ALTER?

The SQL ALTER TABLE command is used to add, delete or modify columns in an existing table. You should also use the ALTER TABLE command to add and drop various constraints on an existing table.

Is ALTER a DDL command?

DDL - which stands for Data Definition Language which comprises SQL commands used for defining the database which includes creating tables, providing specifications, modifying tables and so on. Examples of DDL include CREATE , DROP , ALTER , etc.

What are the functions of ALTER TABLE command?

ALTER TABLE changes the structure of a table. For example, you can add or delete columns, create or destroy indexes, change the type of existing columns, or rename columns or the table itself.

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