Select rows that have at least one null value [duplicate]

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Select rows that have at least one null value [duplicate]



This question already has an answer here:



I had a database that allowed NULL in many of its columns (in all tables). I would like to know if there is a clean way to select from a table all the rows that have at least one value set to null in any column.


NULL



I know that this can be achieved by using:


SELECT * FROM `my_table` WHERE `column_1` is null OR `column_2` is null ... with all columns



but I want to know if there is a cleaner and more general way so I must not make a new query for every new table.
Thanks.



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You can use information_schema.COLUMNS to generate (via CONCAT) SELECT statement(s) with all the columns for all tables.
– Rick James
Aug 26 at 0:41


information_schema.COLUMNS


CONCAT


SELECT




2 Answers
2



Sorry But it cant be done a cleaner way



If you could select all the rows and then apply a function it could be made but it's just not the way SQL was built.



What you "know" is wrong. The correct logic would be:


where column_1 is null or column_2 is null or . . .



This is the correct syntax and a perfectly reasonable approach.





thanks for the correction, that's what i meant. I corrected my post. Though I want to know if there is a more general way that i can apply to many different tables with different column names
– Dknacht
Aug 10 at 19:36





@Dknacht There's nothing that automatically loops over columns dynamically. You could write a stored procedure that gets the column names from INFORMATION_SCHEMA and builds the SQL dynamically.
– Barmar
Aug 10 at 19:52


INFORMATION_SCHEMA

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