Would anyone be able to advise on this, im not sure how to do what I want to do.
I have a table CUSTOMER which contains 10,000 rows and has a column MOBILE_NUMBER
I have an OUTGOING_SMS table which contains 3,500 rows and also has a column MOBILE_NUMBER
I'm looking to find all the customers who have not had an SMS which should be 6,500
I know how to find all the customer who have had an SMS, its a simple join but I'm not sure how to find the inverse.
Any help would be fantastic. cheers
DB, is MySQL.
I have a table CUSTOMER which contains 10,000 rows and has a column MOBILE_NUMBER
I have an OUTGOING_SMS table which contains 3,500 rows and also has a column MOBILE_NUMBER
I'm looking to find all the customers who have not had an SMS which should be 6,500
I know how to find all the customer who have had an SMS, its a simple join but I'm not sure how to find the inverse.
Any help would be fantastic. cheers
DB, is MySQL.
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