Hi..
<b>Specifying Two or More Database Tables as a Left Outer Join</b>
In an inner join, a line from the left-hand database table or join is only included in the selection if there is one or more lines in the right-hand database table that meet the ON condition <cond>. The left outer join, on the other hand, reads lines from the left-hand database table or join even if there is no corresponding line in the right-hand table.
<b>SELECT...
...
FROM <tab> LEFT [OUTER] JOIN <dbtab> [AS <alias>] ON <cond>
<options>
...</b>
<tab> and <dbtab> are subject to the same rules and conditions as in an inner join. The OUTER addition is optional. The tables are linked in the same way as the inner join with the one exception that all lines selected from <tab> are included in the final selection. If <dbtab> does not contain any lines that meet the condition <cond>, the system includes a single line in the selection whose columns from <dbtab> are filled with null values.
In the left outer join, more restrictions apply to the condition <cond> than in the inner join. In addition to the above restrictions:
EQ or = is the only permitted relational operator.
There must be at least one comparison between columns from <tab> and <dbtab>.
The WHERE clause may not contain any comparisons with columns from <dbtab>. All comparisons using columns from <dbtab> must appear in the condition <cond>.
Client Handling
Bluesky
