How to find Null values without specifying attribute (Mariadb)

Question

I would like to do a search to find NULL values across the table without having to determine which of the attributes might contain NULL.

NOTE: By ALL table I mean that somewhere in it you have null, not that the table should be composed entirely of null elements. OK?

Thanks in advance

Answer 1

Lucas, to perform the procedure you want a bit of manual work is required (or a stored Procedure, which escapes some of my knowledge in Mysql).

To do so you can follow the following steps:

1) Run the following select by changing the table name (your table) to find out which columns can receive null values in the desired table.

SELECT GROUP_CONCAT(column_name) FROM information_schema.columns WHERE table_name = 'sua_tabela' AND IS_NULLABLE = 'YES';

Once done, replace "columns..." with the result of the first select and change the name of "sua_table" again. You now need to add an OR (OR) condition for each column you select, followed by the IS NULL condition, as an example below:

SELECT colunas... FROM sua_tabela
WHERE coluna1 IS NULL 
OR coluna2 IS NULL
or colunaN... IS NULL

It is not a difficult job, but the more columns there are and the more repetitive this work will be more tiringso if it is necessary to perform this procedure routinely I advise you to study stored procedures of Mysql so that you can implement this routine that I passed to you in an automated way.

I hope I helped you.