TYPEOF

Return the dialect-neutral data type name of an expression.

Category: miscReturns: STRINGDialect: Standard

Syntax

TYPEOF(expr)

Description

## Overview Returns the dialect-neutral name of the data type of the input expression. Use this function for diagnostics and schema exploration when you want consistent type names across engines. TYPEOF is the dialect-neutral variant of PG_TYPEOF. TYPEOF returns names such as `string`, `integer`, `boolean`; PG_TYPEOF returns the PG-compat equivalents (`text`, `integer`, `boolean`). ## Behavior - Always returns a non-NULL string. - For NULL inputs the type name is reported as `null`. - Deterministic for a given expression tree. - Side effect free. - The type is resolved at plan time from the expression's inferred type, not the runtime value. ## Compatibility - Dialect-neutral alternative to PG_TYPEOF.

Parameters

Name	Type	Description
`expr`		Specifies the expression whose data type name is returned.

Examples

-- Type of an integer
SELECT TYPEOF(42);  -- 'integer'

-- Type of a string
SELECT TYPEOF('hello');  -- 'string'

-- Type of a boolean
SELECT TYPEOF(true);  -- 'boolean'

-- Type of NULL (reported as 'null')
SELECT TYPEOF(NULL);  -- 'null'

-- Inspect column types in a sample row
SELECT TYPEOF(price) AS price_type, TYPEOF(quantity) AS qty_type
FROM retail.catalog.products
LIMIT 1;

Pitfalls

TYPEOF reflects the inferred static type, not the runtime value. Wrapping the argument in a cast changes the result to the cast target.
TYPEOF and PG_TYPEOF return different string representations for the same types. Pick one consistently.
For NULL without an inferred context, the type resolves to `null` rather than a concrete type. Annotate the context if you need a specific type.
Composite types (struct, array) are reported by their top-level name only; descend into fields for finer-grained inspection.