Alter Table Article For Free

MySQL ALTER statement is used when you want to change the name of your table or any table field. It is also used to add or delete an existing column in a table. The ALTER statement is always used with "ADD", "DROP" and "MODIFY" commands according to the situation.

ALTER TABLE is used to add, delete/drop or modify columns in the existing table. It is also used to add and drop various constraints on the existing table. ADD is used to add columns into the existing table.

Use the ALTER TABLE statement to alter the definition of a nonpartitioned table, a partitioned table, a table partition, or a table subpartition....However, for a temporary table you cannot:Add columns of nested table type.Specify referential integrity (foreign key) constraints for an added or modified column.More items...

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.

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. You can also change characteristics such as the storage engine used for the table or the table comment.

The ALTER TABLE statement is used to add, delete, or modify columns in an existing table. The ALTER TABLE statement is also used to add and drop various constraints on an existing table.

Existing tables can be altered with an ALTER TABLE statement. An ALTER TABLE statement is part of DDL, and is for altering a table schema only; we'll look at updating data in a table later in this book.