While alter table adding foreign key getting error in SQL Server

Question

I am trying to add a foreign key in SQL Server to an existing table, but I'm getting an error. Could any one please help me?

Note: objid is present in both table 1 & table 2

ALTER TABLE table1
    ADD CONSTRAINT FK_41_PRICE_INST2PRICE_QTY
    FOREIGN KEY (Table1 PRICE_INST2PRICE_QTY) REFERENCES table2(objid);

Error:

FK_40_PRICE_INST2PRICE_QTY. The conflict occurred in database "test", table "dbo.table2", column 'objid'.

Answer 1

The syntax should be something more like this:

ALTER TABLE table1
    ADD CONSTRAINT FK_41_PRICE_INST2PRICE_QTY
    FOREIGN KEY (PRICE_INST2PRICE_QTY) REFERENCES table2(objid);

You don't need to qualify the column name.

Answer 2

Apart from the error in the syntax, I think there are some values in the objid column that doesn't exist in the PRICE_INST2PRICE_QTY table. You have to check the values between the two columns. This is why you are creating the foreign key to prevent such things.

Answer 3

Do a quick check on you column 'objid' and don't write

 FOREIGN KEY (Table1 PRICE_INST2PRICE_QTY) REFERENCES table2(objid);

It should be more like:

FOREIGN KEY (PRICE_INST2PRICE_QTY) REFERENCES table2(objid);

without table1, because you're working in table1.