Removing Duplicates in a Table based on two Columns

The solution consists in first place to find exactly where the "bad registers" are. If we see the records (BG, CH, 280) and (CH,BG,280), the problems consists that are "equal" if they were inserted always both fields in alfabetical order that is (BG, CH,280). So a record is not good in first opinion, if name2 is
previous to name1.

The query:

SELECT 
	CASE WHEN t1.name1<>(CASE WHEN t1.name1<t1.name2 THEN t1.name1 ELSE t1.name2 end) THEN 'bad register' else 'good registerk' end as clase
	,t1.*
  FROM table1 t1

says that (CH, BG, 280), (HY,CH, 350) are 'wrong register' (what is right), but also says that (CH,CBE, 500) is a 'wrong register' (what is worng).
This last record really isnt´t a 'wrong register' because there isn´t a 'mirror' register (CBE, CH, 250)

So if we use the query:

SELECT 
	CASE WHEN t1.name1<>(CASE WHEN t1.name1<t1.name2 THEN t1.name1 ELSE t1.name2 end) THEN 'wrong register' else 'ok register' end as clase
	,t1.*
  FROM table1 t1
  JOIN table1 t2
  ON t1.name1=t2.name2 AND t1.name2=t2.name1

we only have the real 'wrong register' (because if there is no 'mirrow' register it says that it´s a 'ok register')

Then, the query:

SELECT t1.*
  FROM table1 t1
  JOIN table1 t2
  ON t1.name1=t2.name2 AND t1.name2=t2.name1
  WHERE t1.name1<>(CASE WHEN t1.name1<t1.name2 THEN t1.name1 ELSE t1.name2 end) 

just list the records that you need to delete.

or simplier:

SELECT t1.*
  FROM table1 t1
  JOIN table1 t2
  ON t1.name1=t2.name2 AND t1.name2=t2.name1
  WHERE t1.name1>t1.name2

Finaly the order:

delete TABLEdELETE
	FROM table1 tableDelete
	inner JOIN table1 t1
		on tabledelete.name1=t1.name1 and tabledelete.name2=t1.name2	
	inner JOIN  table1 t2
		ON ( t1.name1>t1.name2 AND t1.name1=t2.name2 AND t1.name2=t2.name1 ) 

deletes the register that you want.

Note: If your data are:
BG CH 1
CH BG 2
CH HY 2
HY CH 3

and you don´t want that the record CH, BG, 2 will be delete then use:

delete TABLEdELETE
	FROM table1 tableDelete
	inner JOIN table1 t1
		on tabledelete.name1=t1.name1 and tabledelete.name2=t1.name2 	
	inner JOIN  table1 t2
		ON ( t1.name1>t1.name2 AND t1.name1=t2.name2 AND t1.name2=t2.name1 AND t1.distance=t2.distance ) 

delete from table1 t1
WHERE t1.name1>t1.name2

Name1	Name2	Distance
BG	CH	280
CH 	BG	280
HY 	CH	350
CH 	CBE	500

select * from table1 where rowid in (select t1.rowid from table1 t1,table1 t2 where t1.Name1>t1.Name2 and t1.Name1=t2.Name2 and t2.Name1=t1.Name2 );

delete from table1 where rowid in (select t1.rowid from table1 t1,table1 t2 where t1.Name1>t1.Name2 and t1.Name1=t2.Name2 and t2.Name1=t1.Name2 );

I have come up with this below SQL query and it works.The main idea is to sort the values in the two columns.

SELECT Name1,Name2,distance from name_tbl INNER JOIN(
SELECT DISTINCT CASE WHEN name1<name2 THEN name1 ELSE name2 END as firstName,
CASE WHEN name1<name2 THEN name2 ELSE name1 END as secondName
FROM name_tbl
)t1
ON name_tbl.name1 = t1.firstName AND name_tbl.name2 = t1.secondName