Is excuse me this kind of multiple table joins?
Select
(select a.c l from a where Anderson, d=b.i d)
The from b;

And is there any difference between the following query results? Thank you for your great god

The select a.c l
From a, b
Where Anderson, d=b.i d;

CodePudding user response:

Are essentially table connection, but the meaning of the former and the latter is different, the former is actually an outer join:
The select a.c l
From a, b
Where Anderson d (+)=b.i d;

CodePudding user response:

refer to the building entrance sky turned a circle response:

multi-table connection is this, please?
Select
(select a.c l from a where Anderson, d=b.i d)
The from b;

And is there any difference between the following query results? Thank you for your great god

The select a.c l
From a, b
Where Anderson, d=b.i d;

The former as a scalar subquery, the latter for connection, in standard difference, there must be a result set may be different, might not have the same performance,

CodePudding user response:

Both meaning must be different, and the select (select a.c l from a where Anderson, d=b.i d) from b; May be an error, when the select a.c l from a where Anderson, d=b.i d return multiple results, will report the result is not the only mistakes

CodePudding user response:

First, if b table, a record, the corresponding multiple records, a table will be an error,
The second, table b of a record, the multiple records corresponding to a table, not an error,
Actually both writing, difference more than the same place,
Try more, there will be more found,

CodePudding user response:

The first for the scalar subquery, the second for the inside connection, there is a difference between a certain,