JAEN

SQL

ALTER TABLE

CautionAlter table structure

ALTER TABLE <t> ADD COLUMN <col> <type>;

Adds/drops/retypes columns. On big tables this locks and rebuilds — schedule production changes.

Examples

  • ALTER TABLE users ADD COLUMN last_login DATETIME;Add a column

Syntax

ALTER TABLE t [ADD|DROP|MODIFY] COLUMN ...;

Before you run it

Long locks on large tables.

Related commands

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