bool() — PostgreSQL JSON function

bool(): convert jsonb to boolean. PostgreSQL json functions — signature, volatility, version applicability and an illustrative example.

Summary

bool is a PostgreSQL built-in function in the JSON Functions group. PostgreSQL’s system catalog (pg_proc) describes it as: “convert jsonb to boolean”.

Signature

bool has 2 documented overloaded forms:

bool(jsonb) → boolean
bool(integer) → boolean

Argument and return types are taken from the pg_proc catalog; internal type names are shown using their readable SQL spellings (for example int4 is shown as integer). (Derived from the catalog — see the linked reference for the canonical documentation.)

Classification

  • Category: JSON Functions
  • Kind: Function
  • Volatility: IMMUTABLE — Marked IMMUTABLE — it always returns the same result for the same arguments and can be used in indexes and other contexts that require immutability.
  • Returns: boolean

Example

Illustrative form (replace placeholder values with your own data):

SELECT bool('{"k":1}'::jsonb);

The example above is illustrative and is meant to show calling syntax only; consult the linked PostgreSQL documentation for exact semantics, edge cases and accepted argument combinations.

Version applicability

bool is present across the surveyed releases (PostgreSQL 15, 16, 17, 18, 19). On older major versions, behaviour may differ in detail — always check the documentation for the version you run.

Related & references

Reference: PostgreSQL documentation — JSON Functions.