upper() — PostgreSQL range function

upper(): uppercase. PostgreSQL range functions — signature, volatility, version applicability and an illustrative example.

The Sev-1 Admin
The Sev-1 Admin  ·  1 min read

Summary

upper is a PostgreSQL built-in function in the Range Functions group. PostgreSQL’s system catalog (pg_proc) describes it as: “uppercase”.

Signature

upper has 3 documented overloaded forms:

upper(text) → text
upper(anyrange) → anyelement
upper(anymultirange) → anyelement

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: Range 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: anyelement, text

Example

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

SELECT upper('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

upper 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 — Range Functions.