Selecting Multiple columns in Sub-query

Question

Hi All,
I've been using three co-related queries to fetch data as shown below in the pseudo code. All these sub-queries are same, except the column name. I want to avoid the same query to be executed thrice for three columns. Is there any way to avoid this?
insert into my_table
select colA,
colB,
(select field1 from table1 where table1.fieldx =tableA.fieldy ) col1,
(select field2 from table1 where table1.fieldx =tableA.fieldy) col2,
(select field3 from table1 where table1.fieldx =tableA.fieldy) col3
from tableA , table B 
where con1= con2
    and con3 = con4
    and con4=con5;All suggestions are welcomed
Regards,
K

Answer 1

Hi,
Perhaps this is what you want:
INSERT INTO my_table (colA, colB. col1, col2, col3)    -- list the columns explicitly
WITH     table_1_summary          AS
     SELECT       fieldx
     ,       MIN (field1)     AS col1
     ,       MIN (field2)     AS col2
     ,       MIN (field3)     AS col3
     FROM       table1
     GROUP BY  fieldx
SELECT       colA
,       colB
,       t1.col1
,       t1.col2
,       t1.col3
FROM       tableA          a
,       tableB          b
,       table_1_summary     t1
WHERE       con1          = con2
AND       con3          = con4
AND       con4          = con5
AND       t1.field1 (+)     = a.fieldy
;Something a little shorter (and a little more efficient) might work, depending on you data, especially what columns are unique.
I hope this answers your question.
If not, post a little sample data (CREATE TABLE and INSERT statements, relevant columns only) for all tables, and also post the results you want from that data.
Explain, using specific examples, how you get those results from that data.
Always say which version of Oracle you're using.