CONCAT_WS(...)

All functions > STRING > CONCAT_WS(...)

Returns a concatenated string from a list of strings with a separator between each element.

Syntax

CONCAT_WS(separator, string, string, …)  ·  CONCAT_WS_FN(separator, ARRAY[…])

CONCAT_WS(separator, string, string, …)  ·  CONCAT_WS_FN(separator, ARRAY[…])

Notes

• Separator is inserted only between non-omitted pieces; skipped NULLs do not add an extra separator
• An empty argument list (after bundling) yields an empty string—no leading or trailing separator
• Variadic form: every string argument must be VARCHAR (bare NULL fails inference—use NULL(VARCHAR) or build an ARRAY[...] and use CONCAT_WS_FN)
• NULL entries in the list are omitted (same idea as CONCAT); use COALESCE when you need empty segments with separators

Related Functions

• CONCAT_WS(...)

Examples

CONCAT_WS(...)

SELECT
    f1 := CONCAT_WS('-', 'A', 'B', 'C'), -- Dash between pieces
    f2 := CONCAT_WS(', ', 'Apple', 'Banana') -- Comma and space
;

Edge cases

SELECT
    f1 := CONCAT_WS('-', 'A', NULL(VARCHAR), 'B') -- NULL piece omitted; no extra delimiter gap
;