Unsupported versions: 7.0
This documentation is for an unsupported version of PostgreSQL.
You may want to view the same page for the current version, or one of the other supported versions listed above instead.

Boolean Type

Postgres supports bool as the SQL3 boolean type. bool can have one of only two states: 'true' or 'false'. A third state, 'unknown', is not implemented and is not suggested in SQL3; NULL is an effective substitute. bool can be used in any boolean expression, and boolean expressions always evaluate to a result compatible with this type.

bool uses 1 byte of storage.

Table 3-17. Postgres Boolean Type

State Output Input
True 't' TRUE, 't', 'true', 'y', 'yes', '1'
False 'f' FALSE, 'f', 'false', 'n', 'no', '0'