Subject | Re: [ib-support] sql - diference in join tables |
---|---|
Author | Svein Erling Tysvaer |
Post date | 2003-03-06T13:31:06Z |
Ronaldo,
At 12:16 06.03.2003 +0000, you wrote:
ON ID1 = ID2. The first is SQL-89, whereas the second is SQL-92. Generally,
I would advice to use the JOIN syntax since it is easier to read and e.g.
eliminates the need for JoinLinks if you are using IBO.
LEFT JOIN, RIGHT JOIN and FULL JOIN, however, are outer joins that gives
all records of at least one table regardless of whether they match any
record in the other table. These are joins that are not available in
SQL-89, hence there is no way you can perform these kinds of joins using
ID1 = ID2.
HTH,
Set
At 12:16 06.03.2003 +0000, you wrote:
>Is there any diference in sql joins using where id1 = id2 or usingit is up to you whether you prefer to use WHERE ID1 = ID2 or JOIN <TABLE>
>the left command ?
ON ID1 = ID2. The first is SQL-89, whereas the second is SQL-92. Generally,
I would advice to use the JOIN syntax since it is easier to read and e.g.
eliminates the need for JoinLinks if you are using IBO.
LEFT JOIN, RIGHT JOIN and FULL JOIN, however, are outer joins that gives
all records of at least one table regardless of whether they match any
record in the other table. These are joins that are not available in
SQL-89, hence there is no way you can perform these kinds of joins using
ID1 = ID2.
HTH,
Set