SQL Dialects Reference/Functions and expressions/Misc expressions
< SQL Dialects Reference < Functions and expressionsMisc functions
This page includes comparison tables which can be big and complex.
While it's perfectly all right to view them in their complete state, it is recommended to install a comparison tables extension that would allow to select particular columns of interest for comparison.
| SQL version | Feature | Standard SQL:2011 |
DB2 | Firebird | Ingres | Linter | MSSQL | MySQL Vers. 5.x |
MonetDB | Oracle Vers. 11.x |
PostgreSQL | SQLite | Virtuoso |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ? | Convert value val to data type type | CAST(val AS type) | ? | CAST(val AS type) | ? | CAST(val AS type) CASTexpression as type TO_CHAR TO_NUMBER TO_DATE |
CAST(val AS type) CONVERT(val, type) |
CONVERT(val, type) CAST(val AS type) |
CAST(val AS type) | CAST(val AS type) | CAST(val AS type) val::type |
CAST(val AS type) | ? |
| ? | Replace NULL within a val with a fallback value, return val intact, if it's non-NULL | COALESCE(val, fallback) | ? | ? | ? | NVL(val, fallback) | COALESCE(val, fallback) ISNULL(val, fallback) |
IFNULL(val, fallback) | IFNULL(val, fallback) | COALESCE(val, fallback) NVL(val, fallback) |
N/A | IFNULL(val, fallback) COALESCE(val, fallback) |
? |
| ? | Return the first non-NULL value from a list of values (val1, val2, ...) | COALESCE(val1, val2, ...) | COALESCE(val1, val2) | COALESCE(val1, val2, ...) | ? | COALESCE(val1, val2, ...) | COALESCE(val1, val2, ...) | COALESCE(val1, val2, ...) | COALESCE(val1, val2, ...) | COALESCE(val1, val2, ...) | COALESCE(val1, val2) | COALESCE(val1, val2, ...) | ? |
| ? | Return NULL if two values a and b are equal | NULLIF(a, b) | ? | NULLIF(a, b) | ? | NULLIF(a, b) | NULLIF(a, b) | NULLIF(a, b) | ? | NULLIF(a, b) | NULLIF(a, b) | NULLIF(a, b) | ? |
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