CONCAT_WS

CONCAT_WS() stands for Concatenate With Separator and is a special form of CONCAT(). The first argument is the separator for the rest of the arguments. The separator is added between the strings to be concatenated. The separator can be a string, as can the rest of the arguments. If the separator is NULL, the result is NULL.

CONCAT_WS() does not skip empty strings. However, it does skip any NULL values after the separator argument.

Syntax

CONCAT_WS(<separator>, <expr1>, ...)

Arguments

Arguments	Description
<separator>	string column
<expr1>	value column

Return Type

A VARCHAR data type value Or NULL data type.

Examples

SELECT CONCAT_WS(',', 'data', 'fuse', 'labs', '2021');
+------------------------------------------------+
| CONCAT_WS(',', 'data', 'fuse', 'labs', '2021') |
+------------------------------------------------+
| data,fuse,labs,2021                            |
+------------------------------------------------+

SELECT CONCAT_WS(',', 'data', NULL, 'bend');
+--------------------------------------+
| CONCAT_WS(',', 'data', NULL, 'bend') |
+--------------------------------------+
| data,bend                            |
+--------------------------------------+


SELECT CONCAT_WS(',', 'data', NULL, NULL, 'bend');
+--------------------------------------------+
| CONCAT_WS(',', 'data', NULL, NULL, 'bend') |
+--------------------------------------------+
| data,bend                                  |
+--------------------------------------------+


SELECT CONCAT_WS(NULL, 'data', 'fuse', 'labs');
+-----------------------------------------+
| CONCAT_WS(NULL, 'data', 'fuse', 'labs') |
+-----------------------------------------+
|                                    NULL |
+-----------------------------------------+

SELECT CONCAT_WS(',', NULL);
+----------------------+
| CONCAT_WS(',', NULL) |
+----------------------+
|                      |
+----------------------+