Question

I am trying to figure out the best Transact-SQL to transform non-relational tables into tables that are more relational, and support foreign keys.

Suppose I have a table FRUIT

    Id  Name        USState

    1   Apple       Washington
    2   Pineapple   Hawaii
    3   Orange      Florida
    4   Peach       Georgia

etc

I want the States to be their own table with an Id and Name :

INSERT INTO USSTATE (Name) Select DISTINCT USState from FRUIT

Now I have table USSTATE

    Id      Name

    1       Alabama
    2       Alaska

etc.

How do I now update the USState value in table FRUIT to point to the Id of USSTATE recursively?

I can do it State by State

DECLARE @USSTATE nvarchar(100)
Set @USSTATE = 'Alabama'
Update FRUIT Set USState = (SELECT Id from USSTATE where Name like @USSTATE)  
Set @USSTATE = 'Alaska'   -- do this for each State?   Arghh!!!

etc etc.

, but I want to do it recursively. Thanks for any help?

Answer 1

UPDATE F
SET F.USState = S.ID
FROM FRUID AS F
INNER JOIN USSTATE AS S ON F.USState = S.Name