MySQL - select 上的内部联接查询错误 1052

Question

Im trying to do a select query on a table along with an inner join afterwards to link data from the owner to the cats

the ownercat is using a foreign key on the id linking to the ownerinfo id

USE CATTERY;
SELECT
OWNERINFO.ID, OWNERINFO.First_Name, OWNERINFO.Last_Name, OWNERINFO.Phone, OWNERINFO.AddrL1, OWNERINFO.AddrL2, OWNERINFO.AddrL3, OWNERINFO.PostCode,
GROUP_CONCAT(DISTINCT OWNERCAT.Chip_ID)
FROM OWNERINFO
INNER JOIN OWNERCAT ON OWNERINFO.ID = OWNERCAT.ID

WHERE ID = 1;

I get returned the following error: Error Code: 1052. Column 'ID' in where clause is ambiguous 0.0014 sec

removing the concat distinct statement still produces the same error, im not sure how to get around this issue

Answer 1

You need to define from which table the ID on WHERE -clause come from (you can use aliases). Secondly, as you are using GROUP_CONCAT , you should have GROUP BY in the query:

SELECT
  oi.ID, 
  oi.First_Name, 
  oi.Last_Name, 
  oi.Phone, 
  oi.AddrL1, 
  oi.AddrL2, 
  oi.AddrL3, 
  oi.PostCode,
  GROUP_CONCAT(DISTINCT oc.Chip_ID)
FROM OWNERINFO oi
  INNER JOIN OWNERCAT oc ON oc.ID=oi.ID
WHERE oi.ID = 1
GROUP BY oi.ID

Answer 2

The problem is in the WHERE clause: ID is ambiguous, because that column is available in both tables.

You may think that, since you are joining the tables on ID , the database is able to tell that it has the same value, but that's not actually the case.

So just qualify the column in the WHERE clause, ie change this:

WHERE ID = 1

To either:

WHERE OWNERINFO.ID = 1

Or the equivalent:

WHERE OWNERCAT.ID = 1

Also please note that your query uses GROUP_CONCAT() , which is an aggregate function. This implies that you need a GROUP BY clause, that should list all non-aggregated column (ie all columns other than the one that is within GROUP_CONCAT() ).