How Do you write if then statements in SQL ?

Question

How Do you write if then statements in SQL ?

Debilon 431

Do you write if then statements in SQL ?

I have a contact table that contains FirstName, LastName, Address, Phone1, Phone2,Email1 and Email2
I have an Owner table that contains AccountNumber, FirstName, LastName, Phone1, Phone2,Email1 and Email2

What i would like to do is check if phone1 and email1 from the contact table exist for a specific owner (FirstName, LastName and Address are the same)
and if so enter the additional Phone2 and Email2 from the contact table to the owner table

in VB / VC i can write an IF - Then statement that if phone1 exist and

FirstName & LastName are the same then enter phone2 into its column

But how do you do so in SQL ?

Erland Sommarskog 121.4K Reputation points MVP Volunteer Moderator

2022-03-12T19:22:25.46+00:00

As I said in my comment in you other thread, the recommendation is that you post the CREATE TABLE statement for you table(s) and INSERT statements with sample data and the desired result given the sample. This makes it easy to copy and paste into a query window to develop a tested solution.

It also helps to clarify ambiguities in your question. I've been reading your question a few times, but it is not clear to me what you want to do.

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Erland Sommarskog 121.4K Reputation points MVP Volunteer Moderator

2022-03-12T19:22:25.46+00:00

As I said in my comment in you other thread, the recommendation is that you post the CREATE TABLE statement for you table(s) and INSERT statements with sample data and the desired result given the sample. This makes it easy to copy and paste into a query window to develop a tested solution.

It also helps to clarify ambiguities in your question. I've been reading your question a few times, but it is not clear to me what you want to do.

Answer 1

Naomi Nosonovsky 8,431

As Erland said, your question is not clear. In general there is CASE expression you can use, IIF function you can use. To check if the column contains data or not you may want to use ISNULL(columnName, '') = '' -- this means that column is either NULL or empty.

Answer 2

Hi @Debilon

check if phone1 and email1 from the contact table exist for a specific owner (FirstName, LastName and Address are the same)
and if so enter the additional Phone2 and Email2 from the contact table to the owner table

According to your description, I can only tell that you may need to use IF Exists, Case When, UPDATE......
Could you please share us your table structure (CREATE TABLE …) and some sample data(INSERT INTO …) along with your expected result? So that we’ll get a right direction and make some test.

Best regards,
LiHong

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How Do you write if then statements in SQL ?

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