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3.5.5 Changing a Column's Default Value

To set a new default for a column, use a command like:

ALTER TABLE products ALTER COLUMN price SET DEFAULT 7.77;

Note that this doesn't affect any existing rows in the table, it just changes the default for future INSERT commands.

To remove any default value, use:

ALTER TABLE products ALTER COLUMN price DROP DEFAULT;

This is effectively the same as setting the default to null. As a consequence, it is not an error to drop a default where one hadn't been defined, because the default is implicitly the null value.