G Guest Feb 3, 2004 #1 I would like to compare 2 tables to find out what are the duplicated and non-duplicated data. Please advise how to do such comparison. Thanks.
I would like to compare 2 tables to find out what are the duplicated and non-duplicated data. Please advise how to do such comparison. Thanks.
M Michel Walsh Feb 3, 2004 #2 Hi, An inner join will tell which are common. Run the wizard to find unmatched records to find those that are in one of the table, but not in the other. If no duplicate initially exist, in each table, individually, then a UNION ALL followed by a GROUP BY may also tell all that: SELECT a.item, COUNT(*) FROM ( SELECT DISTINCT item FROM table1 UNION ALL SELECT DISTINCT item FROM table2 ) As a would return 1 or 2, for each item, giving the number of table in which we can find the said item. Hoping it may help, Vanderghast, Access MVP dEE said: I would like to compare 2 tables to find out what are the duplicated and Click to expand... non-duplicated data. Please advise how to do such comparison. Thanks.
Hi, An inner join will tell which are common. Run the wizard to find unmatched records to find those that are in one of the table, but not in the other. If no duplicate initially exist, in each table, individually, then a UNION ALL followed by a GROUP BY may also tell all that: SELECT a.item, COUNT(*) FROM ( SELECT DISTINCT item FROM table1 UNION ALL SELECT DISTINCT item FROM table2 ) As a would return 1 or 2, for each item, giving the number of table in which we can find the said item. Hoping it may help, Vanderghast, Access MVP dEE said: I would like to compare 2 tables to find out what are the duplicated and Click to expand... non-duplicated data. Please advise how to do such comparison. Thanks.
