Subject | Re: [firebird-support] Odd problem |
---|---|
Author | Brad Pepers |
Post date | 2005-09-22T06:23:43Z |
Helen Borrie wrote:
I had "test left join test parent on test.parent_id = parent.test_id" so
it would seem to me that the resulting columns are either referenced by
"test." which is the columns from the first table in the join or
"parent." which is the columns from the second table in the join. So
what is ambiguous about in the selection columns specifying "test.name"?
I want the name column from the table named test in the table
expression and since I aliased the second table to "parent" then I
should get the name from the first table.
I can see if I just wrote "select name from ..." without specifying a
table that this would be ambiguous but why is "test.name" ambiguous???
--
Brad Pepers
brad@...
> Oh, but it is required, both by Firebird and by the standard. Many DBMS'sCan you explain to me why its ambiguous? In the from part of the select
> (including InterBase) are sloppy about it and are happy to let you write
> ambiguous queries and get (often undetectable) wrong results. Firebird 1.5
> doesn't try to guess anything. Wherever you have correlated elements
> (whether by joins or by subqueries) you'll get spanked if you omit
> identifiers. With self-referencing structures, there never was any
> choice: it's always been "alias or die".
I had "test left join test parent on test.parent_id = parent.test_id" so
it would seem to me that the resulting columns are either referenced by
"test." which is the columns from the first table in the join or
"parent." which is the columns from the second table in the join. So
what is ambiguous about in the selection columns specifying "test.name"?
I want the name column from the table named test in the table
expression and since I aliased the second table to "parent" then I
should get the name from the first table.
I can see if I just wrote "select name from ..." without specifying a
table that this would be ambiguous but why is "test.name" ambiguous???
--
Brad Pepers
brad@...