Can we make one query to get same results from 3 tables

Question

CREATE TABLE TABLE1 (NODEID VARCHAR2(4));
CREATE TABLE TABLE2 (NODEID VARCHAR2(4));
CREATE TABLE TABLE3 (NODEID VARCHAR2(4));
INSERT INTO TABLE1 VALUE('1004');
INSERT INTO TABLE1 VALUE('1004');
INSERT INTO TABLE1 VALUE('1002');
INSERT INTO TABLE1 VALUE('1002');
INSERT INTO TABLE1 VALUE('1001');
INSERT INTO TABLE1 VALUE('1001');
INSERT INTO TABLE1 VALUE('1006');
INSERT INTO TABLE1 VALUE('1006');
INSERT INTO TABLE1 VALUE('1005');
INSERT INTO TABLE1 VALUE('1005');
INSERT INTO TABLE2 VALUE('1004');
INSERT INTO TABLE2 VALUE('1004');
INSERT INTO TABLE2 VALUE('1004');
INSERT INTO TABLE2 VALUE('1002');
INSERT INTO TABLE2 VALUE('1002');
INSERT INTO TABLE2 VALUE('1002');
INSERT INTO TABLE2 VALUE('1002');
INSERT INTO TABLE3 VALUE('1001');
INSERT INTO TABLE3 VALUE('1001');
INSERT INTO TABLE3 VALUE('1006');
INSERT INTO TABLE3 VALUE('1006');
INSERT INTO TABLE3 VALUE('1005');
INSERT INTO TABLE3 VALUE('1005');
INSERT INTO TABLE3 VALUE('1004');
INSERT INTO TABLE3 VALUE('1004');
INSERT INTO TABLE3 VALUE('1004');
INSERT INTO TABLE3 VALUE('1002');
INSERT INTO TABLE3 VALUE('1002');
INSERT INTO TABLE3 VALUE('1002');
INSERT INTO TABLE3 VALUE('1002');
Select count(*), count(distinct nodeid)
from table1, table2,table3
where table1.nodeid=table2.nodeid and table1.nodeid=table3.nodeid;
Select count(*), count(distinct nodeid)
from table1, table3
where table1.nodeid=table2.nodeid;
Select count(*), count(distinct nodeid)
from table2, table3
where table2.nodeid=table3.nodeid;

Answer 1

Aside from your insert statements not working... (should be as follows)...
DROP TABLE TABLE1;
DROP TABLE TABLE2;
DROP TABLE TABLE3;
CREATE TABLE TABLE1 (NODEID VARCHAR2(4));
CREATE TABLE TABLE2 (NODEID VARCHAR2(4));
CREATE TABLE TABLE3 (NODEID VARCHAR2(4));
INSERT INTO TABLE1 VALUES('1004');
INSERT INTO TABLE1 VALUES('1004');
INSERT INTO TABLE1 VALUES('1002');
INSERT INTO TABLE1 VALUES('1002');
INSERT INTO TABLE1 VALUES('1001');
INSERT INTO TABLE1 VALUES('1001');
INSERT INTO TABLE1 VALUES('1006');
INSERT INTO TABLE1 VALUES('1006');
INSERT INTO TABLE1 VALUES('1005');
INSERT INTO TABLE1 VALUES('1005');
INSERT INTO TABLE2 VALUES('1004');
INSERT INTO TABLE2 VALUES('1004');
INSERT INTO TABLE2 VALUES('1004');
INSERT INTO TABLE2 VALUES('1002');
INSERT INTO TABLE2 VALUES('1002');
INSERT INTO TABLE2 VALUES('1002');
INSERT INTO TABLE2 VALUES('1002');
INSERT INTO TABLE3 VALUES('1001');
INSERT INTO TABLE3 VALUES('1001');
INSERT INTO TABLE3 VALUES('1006');
INSERT INTO TABLE3 VALUES('1006');
INSERT INTO TABLE3 VALUES('1005');
INSERT INTO TABLE3 VALUES('1005');
INSERT INTO TABLE3 VALUES('1004');
INSERT INTO TABLE3 VALUES('1004');
INSERT INTO TABLE3 VALUES('1004');
INSERT INTO TABLE3 VALUES('1002');
INSERT INTO TABLE3 VALUES('1002');
INSERT INTO TABLE3 VALUES('1002');
INSERT INTO TABLE3 VALUES('1002');and you're queries not working...
SQL> Select count(*), count(distinct nodeid)
  2  from table1, table2,table3
  3  where table1.nodeid=table2.nodeid and table1.nodeid=table3.nodeid;
Select count(*), count(distinct nodeid)
ERROR at line 1:
ORA-00918: column ambiguously definedI'm guessing you want:
SQL> Select count(*), count(distinct table1.nodeid)
  2  from table1, table2,table3
  3  where table1.nodeid=table2.nodeid and table1.nodeid=table3.nodeid;
  COUNT(*) COUNT(DISTINCTTABLE1.NODEID)
        50                            2You haven't explained to us what database version you are using or what you want the output to look like when these 3 queries are combined.
Please read: {message:id=9360002} and learn to post a good question, and use {noformat}{noformat} tags to show your code/data.