Summary
xpath is a PostgreSQL built-in function in the Array Functions group. PostgreSQL’s system catalog (pg_proc) describes it as: “evaluate XPath expression, with namespaces support”.
Signature
xpath has 2 documented overloaded forms:
xpath(text, xml, text[]) → xml[]
xpath(text, xml) → xml[]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: Array 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:
xml[]
Example
Illustrative form (replace placeholder values with your own data):
SELECT xpath('abc', NULL::xml, ARRAY['abc', 'abc']);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
xpath 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 — Array Functions.