boolean

logical Boolean (true/false)

Reading PG 18·Select a recorded version

Catalog name: pg_catalog.bool
Type OID: 16
Type kind: Base type
Declared length: 1 byte
Storage strategy: plain
Input function: boolin
Output function: boolout
Documented declaration: boolean
Storage Size: 1 byte
Manual description: state of true or false
aliases: bool
coverage: source inventory; exact declared input types for operator classes
manual documentation: dedicated family chapter
manual path: datatype-boolean.html
ranges: Unknown
signature: boolean

Definition PG 18

8.6. Boolean Type

PostgreSQL provides the standard SQL type boolean; see Table 8.19. The boolean type can have several states: “true”, “false”, and a third state, “unknown”, which is represented by the SQL null value.

Table 8.19. Boolean Data Type

Name	Storage Size	Description
`boolean`	1 byte	state of true or false

Boolean constants can be represented in SQL queries by the SQL key words TRUE, FALSE, and NULL.

The datatype input function for type boolean accepts these string representations for the “true” state:

true

yes

on

1

and these representations for the “false” state:

false

no

off

0

Unique prefixes of these strings are also accepted, for example t or n. Leading or trailing whitespace is ignored, and case does not matter.

The datatype output function for type boolean always emits either t or f, as shown in Example 8.2.

Example 8.2. Using the boolean Type

CREATE TABLE test1 (a boolean, b text);
INSERT INTO test1 VALUES (TRUE, 'sic est');
INSERT INTO test1 VALUES (FALSE, 'non est');
SELECT * FROM test1;
 a |    b
---+---------
 t | sic est
 f | non est

SELECT * FROM test1 WHERE a;
 a |    b
---+---------
 t | sic est

The key words TRUE and FALSE are the preferred (SQL-compliant) method for writing Boolean constants in SQL queries. But you can also use the string representations by following the generic string-literal constant syntax described in Section 4.1.2.7, for example 'yes'::boolean.

Note that the parser automatically understands that TRUE and FALSE are of type boolean, but this is not so for NULL because that can have any type. So in some contexts you might have to cast NULL to boolean explicitly, for example NULL::boolean. Conversely, the cast can be omitted from a string-literal Boolean value in contexts where the parser can deduce that the literal must be of type boolean.

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Complete source facts

casts

map[castcontext:e castfunc:bool(int4) castmethod:f castsource:int4 casttarget:bool], map[castcontext:e castfunc:int4(bool) castmethod:f castsource:bool casttarget:int4], map[castcontext:a castfunc:text(bool) castmethod:f castsource:bool casttarget:text], map[castcontext:a castfunc:text(bool) castmethod:f castsource:bool casttarget:varchar], map[castcontext:a castfunc:text(bool) castmethod:f castsource:bool casttarget:bpchar], map[castcontext:e castfunc:bool(jsonb) castmethod:f castsource:jsonb casttarget:bool]

catalog

{"array_type_name":"_bool","array_type_oid":"1000","descr":"boolean, format 't'/'f'","oid":"16","typacl":"_null_","typalign":"c","typanalyze":"-","typarray":"0","typbasetype":"0","typbyval":"t","typcategory":"B","typcollation":"0","typdefault":"_null_","typdefaultbin":"_null_","typdelim":"','","typelem":"0","typinput":"boolin","typisdefined":"t","typispreferred":"t","typlen":"1","typmodin":"-","typmodout":"-","typname":"bool","typnamespace":"pg_catalog","typndims":"0","typnotnull":"f","typoutput":"boolout","typowner":"POSTGRES","typreceive":"boolrecv","typrelid":"0","typsend":"boolsend","typstorage":"p","typsubscript":"-","typtype":"b","typtypmod":"-1"}

operator classes

map[opcdefault:t opcfamily:btree/bool_ops opcintype:bool opckeytype:0 opcmethod:btree opcname:bool_ops opcnamespace:pg_catalog opcowner:POSTGRES], map[opcdefault:t opcfamily:hash/bool_ops opcintype:bool opckeytype:0 opcmethod:hash opcname:bool_ops opcnamespace:pg_catalog opcowner:POSTGRES]

operators

map[descr:less than oid:58 oprcanhash:f oprcanmerge:f oprcode:boollt oprcom:>(bool,bool) oprjoin:scalarltjoinsel oprkind:b oprleft:bool oprname:< oprnamespace:pg_catalog oprnegate:>=(bool,bool) oprowner:POSTGRES oprrest:scalarltsel oprresult:bool oprright:bool], map[descr:greater than oid:59 oprcanhash:f oprcanmerge:f oprcode:boolgt oprcom:<(bool,bool) oprjoin:scalargtjoinsel oprkind:b oprleft:bool oprname:> oprnamespace:pg_catalog oprnegate:<=(bool,bool) oprowner:POSTGRES oprrest:scalargtsel oprresult:bool oprright:bool], map[descr:not equal oid:85 oid_symbol:BooleanNotEqualOperator oprcanhash:f oprcanmerge:f oprcode:boolne oprcom:<>(bool,bool) oprjoin:neqjoinsel oprkind:b oprleft:bool oprname:<> oprnamespace:pg_catalog oprnegate:=(bool,bool) oprowner:POSTGRES oprrest:neqsel oprresult:bool oprright:bool], map[descr:equal oid:91 oid_symbol:BooleanEqualOperator oprcanhash:t oprcanmerge:t oprcode:booleq oprcom:=(bool,bool) oprjoin:eqjoinsel oprkind:b oprleft:bool oprname:= oprnamespace:pg_catalog oprnegate:<>(bool,bool) oprowner:POSTGRES oprrest:eqsel oprresult:bool oprright:bool], map[descr:less than or equal oid:1694 oprcanhash:f oprcanmerge:f oprcode:boolle oprcom:>=(bool,bool) oprjoin:scalarlejoinsel oprkind:b oprleft:bool oprname:<= oprnamespace:pg_catalog oprnegate:>(bool,bool) oprowner:POSTGRES oprrest:scalarlesel oprresult:bool oprright:bool], map[descr:greater than or equal oid:1695 oprcanhash:f oprcanmerge:f oprcode:boolge oprcom:<=(bool,bool) oprjoin:scalargejoinsel oprkind:b oprleft:bool oprname:>= oprnamespace:pg_catalog oprnegate:<(bool,bool) oprowner:POSTGRES oprrest:scalargesel oprresult:bool oprright:bool]

Source references

Full definition and evidence JSON

Definition sources

center · PostgreSQL 18 · 555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f

Text language: en · 555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f