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(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) |
+----------------------+
|                      |
+----------------------+