DatabaseLesson 12Free preview

PostgreSQL DROP COLUMN

This lesson is part of PostgreSQL · All levels

Summary

ALTER TABLE ... DROP COLUMN permanently deletes a column and all of its data. PostgreSQL provides IF EXISTS so that the command does not error when columns are not found, as well as CASCADE when there are other objects that depend on it. Since this removal is difficult to override, check the reference first.

Key points

DROP COLUMN deletes the column and its contents.
If EXIST prevents errors when columns do not exist.
CASCADE removes dependen objects such as views, indexes, or constraints.
Verify the use reference before running the DROP COLUMN in production.

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