SQL JOIN Cheat Sheet

Oracle | SQL JOIN Cheat Sheet

Notes
SQL JOIN Cheat Sheet
[INNER] JOIN
LEFT [OUTER] JOIN
LEFT [OUTER] JOIN (excluding INNER JOIN)
RIGHT [OUTER] JOIN
RIGHT [OUTER] JOIN (excluding INNER JOIN)
FULL [OUTER] JOIN
FULL [OUTER] JOIN (excluding INNER JOIN)
CROSS JOIN
Semi join
Anti join
UNION
INTERSECT

Notes
This page explains how to use different types of SQL JOIN to combines records from two tables.
In practice joining two tables requires that the related columns, used to join these tables, are indexed properly.
The related columns are often the primary and foreign keys of the joined tables.

These tables and their data are used in the examples bellow:
- create table table1 (rownum1 int, c1 char, primary key (rownum1));
  xxxxxxxxxx
  
  create table table1 (rownum1 int, c1 char, primary key (rownum1));
- create table table2 (rownum2 int, c2 char, primary key (rownum2));
  xxxxxxxxxx
  
  create table table2 (rownum2 int, c2 char, primary key (rownum2));
- insert into table1(rownum1,c1) values(1,'a'); insert into table1(rownum1,c1) values(2,'a'); insert into table1(rownum1,c1) values(3,'b'); insert into table1(rownum1,c1) values(4,'c'); insert into table1(rownum1,c1) values(5,'c'); insert into table1(rownum1,c1) values(6,'d'); COMMIT;
  xxxxxxxxxx
  
  insert into table1(rownum1,c1) values(1,'a');
  insert into table1(rownum1,c1) values(2,'a');
  insert into table1(rownum1,c1) values(3,'b');
  insert into table1(rownum1,c1) values(4,'c');
  insert into table1(rownum1,c1) values(5,'c');
  insert into table1(rownum1,c1) values(6,'d');
  
  COMMIT;
- insert into table2(rownum2,c2) values(1,'a'); insert into table2(rownum2,c2) values(2,'b'); insert into table2(rownum2,c2) values(3,'b'); insert into table2(rownum2,c2) values(4,'e'); insert into table2(rownum2,c2) values(5,'e'); insert into table2(rownum2,c2) values(6,'f'); COMMIT;
  xxxxxxxxxx
  
  insert into table2(rownum2,c2) values(1,'a');
  insert into table2(rownum2,c2) values(2,'b');
  insert into table2(rownum2,c2) values(3,'b');
  insert into table2(rownum2,c2) values(4,'e');
  insert into table2(rownum2,c2) values(5,'e');
  insert into table2(rownum2,c2) values(6,'f');
  
  COMMIT;
- Table1 "a" "a" "b" "c" "c" "d"
  xxxxxxxxxx
  
  "a"
  "a"
  "b"
  "c"
  "c"
  "d"
  Table2 "a" "b" "b" "e" "e" "f"
  xxxxxxxxxx
  
  "a"
  "b"
  "b"
  "e"
  "e"
  "f"

[INNER] JOIN

select * from table1 t1 inner join table2 t2 on t1.c1=t2.c2 xxxxxxxxxx select * from table1 t1 inner join table2 t2 on t1.c1=t2.c2

LEFT [OUTER] JOIN

select * from table1 t1 left outer join table2 t2 on t1.c1=t2.c2 xxxxxxxxxx select * from table1 t1 left outer join table2 t2 on t1.c1=t2.c2

LEFT [OUTER] JOIN (excluding INNER JOIN)

select t1.rownum1,t1.c1 from table1 t1 left outer join table2 t2 on t1.c1=t2.c2 where t2.rownum2 is null xxxxxxxxxx select t1.rownum1,t1.c1 from table1 t1 left outer join table2 t2 on t1.c1=t2.c2 where t2.rownum2 is null

RIGHT [OUTER] JOIN

select * from table1 t1 right outer join table2 t2 on t1.c1=t2.c2 xxxxxxxxxx select * from table1 t1 right outer join table2 t2 on t1.c1=t2.c2

RIGHT [OUTER] JOIN (excluding INNER JOIN)

select t2.rownum2,t2.c2 from table1 t1 right outer join table2 t2 on t1.c1=t2.c2 where t1.rownum1 is null xxxxxxxxxx select t2.rownum2,t2.c2 from table1 t1 right outer join table2 t2 on t1.c1=t2.c2 where t1.rownum1 is null

FULL [OUTER] JOIN

select * from table1 t1 full outer join table2 t2 on t1.c1=t2.c2 xxxxxxxxxx select * from table1 t1 full outer join table2 t2 on t1.c1=t2.c2

FULL [OUTER] JOIN (excluding INNER JOIN)

select * from table1 t1 full outer join table2 t2 on t1.c1=t2.c2 where t1.rownum1 is null or t2.rownum2 is null xxxxxxxxxx select * from table1 t1 full outer join table2 t2 on t1.c1=t2.c2 where t1.rownum1 is null or t2.rownum2 is null

CROSS JOIN

select * from table1 t1,table2 t2 xxxxxxxxxx select * from table1 t1,table2 t2

Semi join

select * from table1 t1 where exists ( select 1 from table2 t2 where t2.c2=t1.c1 ) xxxxxxxxxx select * from table1 t1 where exists ( select 1 from table2 t2 where t2.c2=t1.c1 )

Anti join

select * from table1 t1 where not exists ( select 1 from table2 t2 where t2.c2=t1.c1 ) xxxxxxxxxx select * from table1 t1 where not exists ( select 1 from table2 t2 where t2.c2=t1.c1 )

[INNER] JOIN
- Sample Query:
  select t1.rownum1,t1.c1,t2.rownum2,t2.c2 from table1 t1 inner join table2 t2 on t1.c1=t2.c2 order by t1.rownum1,t2.rownum2
  xxxxxxxxxx
  
  select t1.rownum1,t1.c1,t2.rownum2,t2.c2
  from table1 t1
  inner join table2 t2 on t1.c1=t2.c2
  order by t1.rownum1,t2.rownum2
- Pseudo-code:
  for (rownum1,c1) in table1 for (rownum2,c2) in table2 if c1==c2 print rownum1,c1,rownum2,c2
  xxxxxxxxxx
  
  for (rownum1,c1) in table1
  for (rownum2,c2) in table2
  if c1==c2
  print rownum1,c1,rownum2,c2
- Query output:
  
  rownum1 c1 rownum2 c2
  
  1 "a" 1 "a"
  
  2 "a" 1 "a"
  
  3 "b" 2 "b"
  
  3 "b" 3 "b"
LEFT [OUTER] JOIN
- Sample Query:
  select t1.rownum1,t1.c1,t2.rownum2,t2.c2 from table1 t1 left outer join table2 t2 on t1.c1=t2.c2 order by t1.rownum1,t2.rownum2
  xxxxxxxxxx
  
  select t1.rownum1,t1.c1,t2.rownum2,t2.c2
  from table1 t1
  left outer join table2 t2 on t1.c1=t2.c2
  order by t1.rownum1,t2.rownum2
- Pseudo-code:
  for (rownum1,c1) in table1 flag=not-found for (rownum2,c2) in table2 if c1==c2 { print rownum1,c1,rownum2,c2 flag=found } if flag==not-found print rownum1,c1,(null),(null)
  xxxxxxxxxx
  
  for (rownum1,c1) in table1
  flag=not-found
  for (rownum2,c2) in table2
  if c1==c2 {
  print rownum1,c1,rownum2,c2
  flag=found
  }
  if flag==not-found
  print rownum1,c1,(null),(null)
- Query output:
  
  rownum1 c1 rownum2 c2
  
  1 "a" 1 "a"
  
  2 "a" 1 "a"
  
  3 "b" 2 "b"
  
  3 "b" 3 "b"
  
  4 "c" (null) (null)
  
  5 "c" (null) (null)
  
  6 "d" (null) (null)
LEFT [OUTER] JOIN (excluding INNER JOIN)
- Sample Query:
  select t1.rownum1,t1.c1 from table1 t1 left outer join table2 t2 on t1.c1=t2.c2 where t2.rownum2 is null order by t1.rownum1
  xxxxxxxxxx
  
  select t1.rownum1,t1.c1
  from table1 t1
  left outer join table2 t2 on t1.c1=t2.c2
  where t2.rownum2 is null
  order by t1.rownum1
- Pseudo-code:
  for (rownum1,c1) in table1 flag=not-found for c2 in table2 if c1==c2 { flag=found break } if flag==not-found print rownum1,c1
  xxxxxxxxxx
  
  for (rownum1,c1) in table1
  flag=not-found
  for c2 in table2
  if c1==c2 {
  flag=found
  break
  }
  if flag==not-found
  print rownum1,c1
- Query output:
  
  rownum1 c1
  
  4 "c"
  
  5 "c"
  
  6 "d"
RIGHT [OUTER] JOIN
- Sample Query:
  select t1.rownum1,t1.c1,t2.rownum2,t2.c2 from table1 t1 right outer join table2 t2 on t1.c1=t2.c2 order by t1.rownum1,t2.rownum2
  xxxxxxxxxx
  
  select t1.rownum1,t1.c1,t2.rownum2,t2.c2
  from table1 t1
  right outer join table2 t2 on t1.c1=t2.c2
  order by t1.rownum1,t2.rownum2
- Pseudo-code:
  for (rownum2,c2) in table2 flag=not-found for (rownum1,c1) in table1 if c1==c2 { print rownum1,c1,rownum2,c2 flag=found } if flag==not-found print (null),(null),rownum2,c2
  xxxxxxxxxx
  
  for (rownum2,c2) in table2
  flag=not-found
  for (rownum1,c1) in table1
  if c1==c2 {
  print rownum1,c1,rownum2,c2
  flag=found
  }
  if flag==not-found
  print (null),(null),rownum2,c2
- Query output:
  
  rownum1 c1 rownum2 c2
  
  1 "a" 1 "a"
  
  2 "a" 1 "a"
  
  3 "b" 2 "b"
  
  3 "b" 3 "b"
  
  (null) (null) 4 "e"
  
  (null) (null) 5 "e"
  
  (null) (null) 6 "f"
RIGHT [OUTER] JOIN (excluding INNER JOIN)
- Sample Query:
  select t2.rownum2,t2.c2 from table1 t1 right outer join table2 t2 on t1.c1=t2.c2 where t1.rownum1 is null order by t2.rownum2
  xxxxxxxxxx
  
  select t2.rownum2,t2.c2
  from table1 t1
  right outer join table2 t2 on t1.c1=t2.c2
  where t1.rownum1 is null
  order by t2.rownum2
- Pseudo-code:
  for (rownum2,c2) in table2 flag=not-found for c1 in table1 if c1==c2 { flag=found break } if flag==not-found print rownum2,c2
  xxxxxxxxxx
  
  for (rownum2,c2) in table2
  flag=not-found
  for c1 in table1
  if c1==c2 {
  flag=found
  break
  }
  if flag==not-found
  print rownum2,c2
- Query output:
  
  rownum2 c2
  
  4 "e"
  
  5 "e"
  
  6 "f"
FULL [OUTER] JOIN
- Sample Query (1):
  select t1.rownum1,t1.c1,t2.rownum2,t2.c2 from table1 t1 full outer join table2 t2 on t1.c1=t2.c2 order by t1.rownum1,t2.rownum2
  xxxxxxxxxx
  
  select t1.rownum1,t1.c1,t2.rownum2,t2.c2
  from table1 t1
  full outer join table2 t2 on t1.c1=t2.c2
  order by t1.rownum1,t2.rownum2
- Sample Query (2):
  select t1.rownum1,t1.c1,t2.rownum2,t2.c2 from table1 t1 left outer join table2 t2 on t1.c1=t2.c2 union select t1.rownum1,t1.c1,t2.rownum2,t2.c2 from table1 t1 right outer join table2 t2 on t1.c1=t2.c2
  xxxxxxxxxx
  
  select t1.rownum1,t1.c1,t2.rownum2,t2.c2 from table1 t1 left outer join table2 t2 on t1.c1=t2.c2
  union
  select t1.rownum1,t1.c1,t2.rownum2,t2.c2 from table1 t1 right outer join table2 t2 on t1.c1=t2.c2
- Pseudo-code:
  for (rownum1,c1) in table1 flag=not-found for (rownum2,c2) in table2 if c1==c2 { print rownum1,c1,rownum2,c2 flag=found } if flag==not-found print rownum1,c1,(null),(null) for (rownum2,c2) in table2 flag=not-found for c1 in table1 if c1==c2 { flag=found break } if flag==not-found print (null),(null),rownum2,c2
  xxxxxxxxxx
  
  for (rownum1,c1) in table1
  flag=not-found
  for (rownum2,c2) in table2
  if c1==c2 {
  print rownum1,c1,rownum2,c2
  flag=found
  }
  if flag==not-found
  print rownum1,c1,(null),(null)
  
  for (rownum2,c2) in table2
  flag=not-found
  for c1 in table1
  if c1==c2 {
  flag=found
  break
  }
  if flag==not-found
  print (null),(null),rownum2,c2
- Query output:
  
  rownum1 c1 rownum2 c2
  
  1 "a" 1 "a"
  
  2 "a" 1 "a"
  
  3 "b" 2 "b"
  
  3 "b" 3 "b"
  
  4 "c" (null) (null)
  
  5 "c" (null) (null)
  
  6 "d" (null) (null)
  
  (null) (null) 4 "e"
  
  (null) (null) 5 "e"
  
  (null) (null) 6 "f"
FULL [OUTER] JOIN (excluding INNER JOIN)
- Sample Query (1):
  select t1.rownum1,t1.c1,t2.rownum2,t2.c2 from table1 t1 full outer join table2 t2 on t1.c1=t2.c2 where t1.rownum1 is null or t2.rownum2 is null order by t1.rownum1,t2.rownum2
  xxxxxxxxxx
  
  select t1.rownum1,t1.c1,t2.rownum2,t2.c2
  from table1 t1
  full outer join table2 t2 on t1.c1=t2.c2
  where t1.rownum1 is null or t2.rownum2 is null
  order by t1.rownum1,t2.rownum2
- Sample Query (2):
  select t1.rownum1,t1.c1,t2.rownum2,t2.c2 from table1 t1 left outer join table2 t2 on t1.c1=t2.c2 where t2.rownum2 is null union select t1.rownum1,t1.c1,t2.rownum2,t2.c2 from table1 t1 right outer join table2 t2 on t1.c1=t2.c2 where t1.rownum1 is null
  xxxxxxxxxx
  
  select t1.rownum1,t1.c1,t2.rownum2,t2.c2 from table1 t1 left outer join table2 t2 on t1.c1=t2.c2 where t2.rownum2 is null
  union
  select t1.rownum1,t1.c1,t2.rownum2,t2.c2 from table1 t1 right outer join table2 t2 on t1.c1=t2.c2 where t1.rownum1 is null
- Pseudo-code:
  for (rownum1,c1) in table1 flag=not-found for c2 in table2 if c1==c2 { flag=found break } if flag==not-found print rownum1,c1,(null),(null) for (rownum2,c2) in table2 flag=not-found for c1 in table1 if c1==c2 { flag=found break } if flag==not-found print (null),(null),rownum2,c2
  xxxxxxxxxx
  
  for (rownum1,c1) in table1
  flag=not-found
  for c2 in table2
  if c1==c2 {
  flag=found
  break
  }
  if flag==not-found
  print rownum1,c1,(null),(null)
  
  for (rownum2,c2) in table2
  flag=not-found
  for c1 in table1
  if c1==c2 {
  flag=found
  break
  }
  if flag==not-found
  print (null),(null),rownum2,c2
- Query output:
  
  rownum1 c1 rownum2 c2
  
  4 "c" (null) (null)
  
  5 "c" (null) (null)
  
  6 "d" (null) (null)
  
  (null) (null) 4 "e"
  
  (null) (null) 5 "e"
  
  (null) (null) 6 "f"

rownum1	c1
4	"c"
5	"c"
6	"d"

rownum2	c2
4	"e"
5	"e"
6	"f"

rownum1	c1	rownum2	c2
4	"c"	(null)	(null)
5	"c"	(null)	(null)
6	"d"	(null)	(null)
(null)	(null)	4	"e"
(null)	(null)	5	"e"
(null)	(null)	6	"f"

CROSS JOIN

Sample Query:
select t1.rownum1,t1.c1,t2.rownum2,t2.c2 from table1 t1,table2 t2 order by t1.rownum1,t2.rownum2
xxxxxxxxxx

select t1.rownum1,t1.c1,t2.rownum2,t2.c2
from table1 t1,table2 t2
order by t1.rownum1,t2.rownum2

Pseudo-code:

xxxxxxxxxx
 
for (rownum1,c1) in table1
  for (rownum2,c2) in table2
    print rownum1,c1,rownum2,c2

Query output:

rownum1	c1	rownum2	c2
1	"a"	1	"a"
1	"a"	2	"b"
1	"a"	3	"b"
1	"a"	4	"e"
1	"a"	5	"e"
1	"a"	6	"f"
2	"a"	1	"a"
2	"a"	2	"b"
2	"a"	3	"b"
2	"a"	4	"e"
2	"a"	5	"e"
2	"a"	6	"f"
3	"b"	1	"a"
3	"b"	2	"b"
3	"b"	3	"b"
3	"b"	4	"e"
3	"b"	5	"e"
3	"b"	6	"f"
4	"c"	1	"a"
4	"c"	2	"b"
4	"c"	3	"b"
4	"c"	4	"e"
4	"c"	5	"e"
4	"c"	6	"f"
5	"c"	1	"a"
5	"c"	2	"b"
5	"c"	3	"b"
5	"c"	4	"e"
5	"c"	5	"e"
5	"c"	6	"f"
6	"d"	1	"a"
6	"d"	2	"b"
6	"d"	3	"b"
6	"d"	4	"e"
6	"d"	5	"e"
6	"d"	6	"f"

Semi join
- Sample Query (1):
  select t1.rownum1,t1.c1 from table1 t1 where t1.c1 in ( select t2.c2 from table2 t2 ) order by t1.rownum1
  xxxxxxxxxx
  
  select t1.rownum1,t1.c1
  from table1 t1
  where t1.c1 in
  (
  select t2.c2
  from table2 t2
  )
  order by t1.rownum1
- Sample Query (2):
  select t1.rownum1,t1.c1 from table1 t1 where exists ( select 1 from table2 t2 where t2.c2=t1.c1 ) order by t1.rownum1
  xxxxxxxxxx
  
  select t1.rownum1,t1.c1
  from table1 t1
  where exists
  (
  select 1
  from table2 t2
  where t2.c2=t1.c1
  )
  order by t1.rownum1
- Pseudo-code:
  for (rownum1,c1) in table1 for c2 in table2 if c1==c2 { print rownum1,c1 break }
  xxxxxxxxxx
  
  for (rownum1,c1) in table1
  for c2 in table2
  if c1==c2 {
  print rownum1,c1
  break
  }
- Query output:
  
  rownum1 c1
  
  1 "a"
  
  2 "a"
  
  3 "b"
Anti join
- Sample Query (1):
  select t1.rownum1,t1.c1 from table1 t1 where t1.c1 not in ( select t2.c2 from table2 t2 ) order by t1.rownum1
  xxxxxxxxxx
  
  select t1.rownum1,t1.c1
  from table1 t1
  where t1.c1 not in
  (
  select t2.c2
  from table2 t2
  )
  order by t1.rownum1
- Sample Query (2):
  select t1.rownum1,t1.c1 from table1 t1 where not exists ( select 1 from table2 t2 where t2.c2=t1.c1 ) order by t1.rownum1
  xxxxxxxxxx
  
  select t1.rownum1,t1.c1
  from table1 t1
  where not exists
  (
  select 1
  from table2 t2
  where t2.c2=t1.c1
  )
  order by t1.rownum1
- Pseudo-code:
  for (rownum1,c1) in table1 flag=not-found for c2 in table2 if c1==c2 { flag=found break } if flag==not-found print rownum1,c1
  xxxxxxxxxx
  
  for (rownum1,c1) in table1
  flag=not-found
  for c2 in table2
  if c1==c2 {
  flag=found
  break
  }
  if flag==not-found
  print rownum1,c1
- Query output:
  
  rownum1 c1
  
  4 "c"
  
  5 "c"
  
  6 "d"
UNION
- Sample Query:
  select t1.rownum1 as "rownum",t1.c1 as "c" from table1 t1 union select t2.rownum2 as "rownum",t2.c2 as "c" from table2 t2
  xxxxxxxxxx
  
  select t1.rownum1 as "rownum",t1.c1 as "c" from table1 t1
  union
  select t2.rownum2 as "rownum",t2.c2 as "c" from table2 t2
- Pseudo-code:
  for (rownum1,c1) in table1 for (rownum2,c2) in table2 if rownum1==rownum2 && c1==c2 { put (rownum1,c1) in set-without-duplicates break } for (rownum1,c1) in set-without-duplicates print rownum1,c1 for (rownum1,c1) in table1 if (rownum1,c1) not in set-without-duplicates print rownum1,c1 for (rownum2,c2) in table2 if (rownum2,c2) not in set-without-duplicates print rownum2,c2
  xxxxxxxxxx
  
  for (rownum1,c1) in table1
  for (rownum2,c2) in table2
  if rownum1==rownum2 && c1==c2 {
  put (rownum1,c1) in set-without-duplicates
  break
  }
  
  for (rownum1,c1) in set-without-duplicates
  print rownum1,c1
  
  for (rownum1,c1) in table1
  if (rownum1,c1) not in set-without-duplicates
  print rownum1,c1
  
  for (rownum2,c2) in table2
  if (rownum2,c2) not in set-without-duplicates
  print rownum2,c2
- Query output:
  
  rownum c
  
  1 "a"
  
  2 "a"
  
  2 "b"
  
  3 "b"
  
  4 "c"
  
  4 "e"
  
  5 "c"
  
  5 "e"
  
  6 "d"
  
  6 "f"
INTERSECT
- Sample Query:
  select t1.rownum1 as "rownum",t1.c1 as "c" from table1 t1 intersect select t2.rownum2 as "rownum",t2.c2 as "c" from table2 t2
  xxxxxxxxxx
  
  select t1.rownum1 as "rownum",t1.c1 as "c" from table1 t1
  intersect
  select t2.rownum2 as "rownum",t2.c2 as "c" from table2 t2
- Pseudo-code:
  for (rownum1,c1) in table1 for (rownum2,c2) in table2 if rownum1==rownum2 && c1==c2 { put (rownum1,c1) in set-without-duplicates break } for (rownum1,c1) in set-without-duplicates print rownum1,c1
  xxxxxxxxxx
  
  for (rownum1,c1) in table1
  for (rownum2,c2) in table2
  if rownum1==rownum2 && c1==c2 {
  put (rownum1,c1) in set-without-duplicates
  break
  }
  
  for (rownum1,c1) in set-without-duplicates
  print rownum1,c1
- Query output:
  
  rownum c
  
  1 "a"
  
  3 "b"

rownum1	c1	rownum2	c2
1	"a"	1	"a"
1	"a"	2	"b"
1	"a"	3	"b"
1	"a"	4	"e"
1	"a"	5	"e"
1	"a"	6	"f"
2	"a"	1	"a"
2	"a"	2	"b"
2	"a"	3	"b"
2	"a"	4	"e"
2	"a"	5	"e"
2	"a"	6	"f"
3	"b"	1	"a"
3	"b"	2	"b"
3	"b"	3	"b"
3	"b"	4	"e"
3	"b"	5	"e"
3	"b"	6	"f"
4	"c"	1	"a"
4	"c"	2	"b"
4	"c"	3	"b"
4	"c"	4	"e"
4	"c"	5	"e"
4	"c"	6	"f"
5	"c"	1	"a"
5	"c"	2	"b"
5	"c"	3	"b"
5	"c"	4	"e"
5	"c"	5	"e"
5	"c"	6	"f"
6	"d"	1	"a"
6	"d"	2	"b"
6	"d"	3	"b"
6	"d"	4	"e"
6	"d"	5	"e"
6	"d"	6	"f"

rownum1	c1	rownum2	c2
1	"a"	1	"a"
1	"a"	2	"b"
1	"a"	3	"b"
1	"a"	4	"e"
1	"a"	5	"e"
1	"a"	6	"f"
2	"a"	1	"a"
2	"a"	2	"b"
2	"a"	3	"b"
2	"a"	4	"e"
2	"a"	5	"e"
2	"a"	6	"f"
3	"b"	1	"a"
3	"b"	2	"b"
3	"b"	3	"b"
3	"b"	4	"e"
3	"b"	5	"e"
3	"b"	6	"f"
4	"c"	1	"a"
4	"c"	2	"b"
4	"c"	3	"b"
4	"c"	4	"e"
4	"c"	5	"e"
4	"c"	6	"f"
5	"c"	1	"a"
5	"c"	2	"b"
5	"c"	3	"b"
5	"c"	4	"e"
5	"c"	5	"e"
5	"c"	6	"f"
6	"d"	1	"a"
6	"d"	2	"b"
6	"d"	3	"b"
6	"d"	4	"e"
6	"d"	5	"e"
6	"d"	6	"f"

rownum1	c1	rownum2	c2
1	"a"	1	"a"
1	"a"	2	"b"
1	"a"	3	"b"
1	"a"	4	"e"
1	"a"	5	"e"
1	"a"	6	"f"
2	"a"	1	"a"
2	"a"	2	"b"
2	"a"	3	"b"
2	"a"	4	"e"
2	"a"	5	"e"
2	"a"	6	"f"
3	"b"	1	"a"
3	"b"	2	"b"
3	"b"	3	"b"
3	"b"	4	"e"
3	"b"	5	"e"
3	"b"	6	"f"
4	"c"	1	"a"
4	"c"	2	"b"
4	"c"	3	"b"
4	"c"	4	"e"
4	"c"	5	"e"
4	"c"	6	"f"
5	"c"	1	"a"
5	"c"	2	"b"
5	"c"	3	"b"
5	"c"	4	"e"
5	"c"	5	"e"
5	"c"	6	"f"
6	"d"	1	"a"
6	"d"	2	"b"
6	"d"	3	"b"
6	"d"	4	"e"
6	"d"	5	"e"
6	"d"	6	"f"