How to Concatenate All Columns in MySQL: Exploring Alternative Approaches?

Concatenation of All Columns in MySQL: Alternative Approaches

In MySQL, concatenating all columns using the * keyword is not feasible. To retrieve a concatenated string of values across all columns, an explicit list of column names is required.

Explicit Column Listing:

The simplest approach is to manually concatenate individual columns:

SELECT CONCAT(col1, col2, col3, ....)
FROM yourtable

CONCAT_WS Function:

The CONCAT_WS function can be used to concatenate columns while skipping null values:

SELECT CONCAT_WS(',', col1, col2, col3, ....)
FROM yourtable

Dynamic Query Generation:

To avoid manually specifying column names, a dynamic query can be created:

SELECT `column_name`
FROM `information_schema`.`columns`
WHERE `table_schema`=DATABASE()
AND `table_name`='yourtable';

This query retrieves all column names in the table. Using GROUP_CONCAT, these names can be transformed into a comma-separated string:

GROUP_CONCAT(CONCAT('`', column_name, '`'))

Finally, these elements can be combined to create a dynamic query:

SELECT
CONCAT(
'SELECT CONCAT_WS(\'\',',
GROUP_CONCAT(CONCAT('`', column_name, '`') ORDER BY column_name),
') AS all_columns FROM yourtable;')
FROM `information_schema`.`columns`
WHERE `table_schema`=DATABASE()
AND `table_name`='yourtable'
INTO @sql;

This query sets the @sql string to the concatenated column names. The following code executes this query:

PREPARE stmt FROM @sql;
EXECUTE stmt;

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