Updating Statement in SQL/PSQL

Question

i am new in the SQL field and i have a dumb question. Lets pretend I have a table in my database, which contains the following information:

ID        name     food
1         Max      apple
2         Anne     banana
3         Tom      kiwi

lets pretend that this is a kindergarden group that ate these foods. 2 Hors later Max ate strawberries and i want ot add this in the list as well. I want the list to look like this:

ID        name     food
1         Max      apple, strawberries
2         Anne     banana
3         Tom      kiwi

I already tried it with the UPDATE statement in SQL, but all of them want an if statement, which i personally dont understand. Does someone has an idea, how i can do it in one statement? Thanks!

Answer 1

The best thing you could do is to use several tables:

• Users (ID, name)
• Food (ID, name)
• UserFoods (ID (optional), user_id, food_id)

Then, you could associate as many food as you want to each user. You could also add a datetime column to UserFoods if needed, etc.

*You would not use UPDATE but SET and DELETE statements...

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Said that, the answer to your question would be this:

UPDATE users 
   SET food = CONCAT(food, ', ', 'strawberries') 
 WHERE name = 'Max';

Explanation: It selects the table users and it concatenates the current food , a comma and space , and strawberries to the food field of the user called Max .

I've used the user name but you should use the ID since there could be a lot of users called Max ...