# Miscellaneous > Structured Query Language (SQL) >  how to make this query?

## Swirl

Hello all,

I have the following table:

create table Sale(
	bankname			char(8)		null,
	controlename	        char(10)     	not null,
	creditcardnummer	        numeric(19)      	null,
	username         		char(10)	        not null,
	accountnummer		numeric(7)   	null, 
	constraint pk_username primary key(username)
)

I want to make a case/trigger where the following happens:
If the word "Creditcard" has been inserted in controlename then creditnummer must contain numbers else it will be NULL.

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## skhanal

Use CHECK Constraint.

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## Swirl

thank you for the reply

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