Scalar Functions — Type Conversion

Type conversion functions cast values between KQL's scalar types. The basic numeric and string casts work across all dialects. More advanced conversions like toguid() and gettype() are only available in ClickHouse, PostgreSQL, and DuckDB. typeof() has no SQL equivalent and is not supported in any dialect.

Legend: ✅ Supported · ⚠️ Approximated · ❌ Not Supported · 🔄 Rewritten

Function	SQLite	MySQL	ClickHouse	PostgreSQL	DuckDB	Notes
`tostring()`	✅	✅	✅	✅	✅	SQLite/Postgres: `TEXT`; MySQL: `CHAR`; DuckDB: `VARCHAR`
`todouble()` / `toreal()`	✅	✅	✅	✅	✅	`CAST(... AS REAL)`; DuckDB: `DOUBLE`
`toint()` / `tolong()`	✅	✅	✅	✅	✅	SQLite/PostgreSQL/DuckDB: `CAST(... AS BIGINT)`; MySQL: `CAST(... AS SIGNED)`; ClickHouse: `toInt64()` (not a `CAST`)
`tobool()`	✅	✅	✅	✅	✅	SQLite/Postgres: `INTEGER`; MySQL: `SIGNED`; DuckDB: `BOOLEAN`
`todatetime()`	✅	✅	✅	✅	✅	Postgres/DuckDB: `CAST(... AS TIMESTAMP)`; MySQL: `DATETIME`; SQLite: `datetime()`
`totimespan()`	⚠️	⚠️	⚠️	✅	✅	Postgres/DuckDB: `CAST(... AS INTERVAL)`; MySQL/SQLite/ClickHouse approximate as seconds
`todecimal()`	✅	✅	✅	✅	✅	`CAST(... AS DECIMAL)`; MySQL: `DECIMAL(38,10)`
`todynamic()` / `toobject()`	❌	✅	✅	✅	✅	Postgres: `jsonb`; DuckDB: `JSON`; MySQL: `JSON_EXTRACT`
`toguid()`	❌	❌	✅	✅	✅	ClickHouse: `toUUID`; Postgres/DuckDB: `CAST(... AS UUID)`
`gettype()`	❌	❌	✅	✅	✅	ClickHouse: `toTypeName`; Postgres: `pg_typeof`; DuckDB: `typeof`
`typeof()`	❌	❌	❌	❌	❌	Compile-time hint; no SQL equivalent