CONCAT_WS

Description

Use the first parameter sep as the connector to concatenate the second parameter and all subsequent parameters (or all strings in ARRAY) into a string. Special cases:

• If the separator is NULL, NULL is returned.

The CONCAT_WS function does not skip empty strings, but skips NULL values.

Syntax

CONCAT_WS ( <sep> , <str> [ , <str> ] )
CONCAT_WS ( <sep> , <array> )

Parameters

Parameter	Description
<sep>	Connector for concatenating strings
<str>	String to be concatenated
<array>	Array to be concatenated

Return value

Parameter <sep> or <array> The string concatenated with <str>. Special cases:

• If delimiter is NULL, returns NULL.

Example

Concatenate strings together using or

SELECT CONCAT_WS("or", "d", "is"),CONCAT_WS(NULL, "d", "is"),CONCAT_WS('or', 'd', NULL, 'is')

+----------------------------+----------------------------+------------------------------------------+
| concat_ws('or', 'd', 'is') | concat_ws(NULL, 'd', 'is') | concat_ws('or', 'd', NULL, 'is') |
+----------------------------+----------------------------+------------------------------------------+
| doris                      | NULL                       | doris                              |
+----------------------------+----------------------------+------------------------------------------+

Concatenate array arrays together using or

SELECT CONCAT_WS("or", ["d", "is"]),CONCAT_WS(NULL, ["d", "is"]),CONCAT_WS("or", ["d", NULL,"is"])

+------------------------------+------------------------------+------------------------------------+
| concat_ws('or', ['d', 'is']) | concat_ws(NULL, ['d', 'is']) | concat_ws('or', ['d', NULL, 'is']) |
+------------------------------+------------------------------+------------------------------------+
| doris                        | NULL                         | doris                              |
+------------------------------+------------------------------+------------------------------------+