Hi there,

City column is defined as
CITY CHAR(8),

But when it's inserted with a null value, the following error is occured:

Cannot add or update a child row: a foreign key constraint fails (`retail`.`sells`, CONSTRAINT `sells_ibfk_1` FOREIGN KEY (`CITY`) REFERENCES `cities` (`CITY_ID`))

The foreign key is defined as:

FOREIGN KEY(CITY) REFERENCES retail.CITIES(CITY_ID),

What's the problem and how is it fixed?

Thanks,

please run this query and show the results --then please run this query and show the results --then please show the entire INSERT statement that failed