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(seperator, column1, ...)

Arguments

Arguments	Description
separator	string column
column	value column

Return Type

A String 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(',', number, 'data', number+1) from numbers(3) order by number;
+----------------------------------------------+
| CONCAT_WS(',', number, 'data', (number + 1)) |
+----------------------------------------------+
| 0,data,1                                     |
| 1,data,2                                     |
| 2,data,3                                     |
+----------------------------------------------+

SELECT CONCAT_WS(NULL, number, 'data') from numbers(3);
+---------------------------------+
| CONCAT_WS(NULL, number, 'data') |
+---------------------------------+
|                            NULL |
|                            NULL |
|                            NULL |
+---------------------------------+


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