Two queries when Joined together adds more records and duplicates records - sql

Question

I have two queries. First Query: Raw data for the clock in. Second Query: Raw data for the clock out. When i combined the two queries together i get duplicated records. On my Raw Check in there are only 2 records and for my clock out query there are 6 records. When I combine the two Queries together i get the total of 12 records with a lot of duplicated entries on both sides.
First Query Code:
SELECT USERINFO.Badgenumber, USERINFO.name, DateValue([Time]) AS DateValue, TimeValue([Time]) AS TimeValue, acc_monitor_log.device_name, Dev.ClockINOut
FROM (Dev INNER JOIN acc_monitor_log ON Dev.DeviceName = acc_monitor_log.device_name) INNER JOIN USERINFO ON acc_monitor_log.pin = USERINFO.Badgenumber
WHERE (((USERINFO.name) Is Null Or (USERINFO.name) Like "*" & [Forms]![Query].[NameQ] & "*") AND ((DateValue([Time]))>=[Forms]![Query]![StartDateQ] And (DateValue([Time]))<=[Forms]![Query]![EndDateQ]) AND ((TimeValue([Time]))>=[Forms]![Query]![StartTimeQ] And (TimeValue([Time]))<=[Forms]![Query]![EndTimeQ]) AND ((Dev.ClockINOut)="Clock In"))
ORDER BY USERINFO.name, DateValue([Time]);
Second Query Code:
SELECT USERINFO.Badgenumber, USERINFO.name, DateValue([Time]) AS DateValue, TimeValue([Time]) AS TimeValue, acc_monitor_log.device_name, Dev.ClockINOut
FROM (Dev INNER JOIN acc_monitor_log ON Dev.DeviceName = acc_monitor_log.device_name) INNER JOIN USERINFO ON acc_monitor_log.pin = USERINFO.Badgenumber
WHERE (((USERINFO.name) Is Null Or (USERINFO.name) Like "*" & Forms!Query.NameQ & "*") And ((DateValue([Time]))>=Forms!Query!StartDateQ And (DateValue([Time]))<=Forms!Query!EndDateQ) And ((TimeValue([Time]))>=Forms!Query!StartTimeQ And (TimeValue([Time]))<=Forms!Query!EndTimeQ) And ((Dev.ClockINOut)="Clock Out"))
ORDER BY USERINFO.name, DateValue([Time]);
And the Combined Query of the two above queries:
SELECT RQOut.Badgenumber, RQOut.name, RQOut.DateValue, RQOut.TimeValue, RQOut.ClockINOut, RQIn.TimeValue, RQIn.device_name, RQIn.ClockINOut, [RQIn].[TimeValue]-[RQOut].[TimeValue] AS Timess
FROM RQOut INNER JOIN RQIn ON (RQOut.Badgenumber = RQIn.Badgenumber) AND (RQOut.name = RQIn.name) AND (RQOut.DateValue = RQIn.DateValue)
WHERE (((RQOut.name) Is Null Or (RQOut.name) Like "*" & [Forms]![Query].[NameQ] & "*") AND ((RQOut.DateValue)>=[Forms]![Query]![StartDateQ] And (RQOut.DateValue)<=[Forms]![Query]![EndDateQ]) AND ((RQOut.TimeValue)>=[Forms]![Query]![StartTimeQ] And (RQOut.TimeValue)<=[Forms]![Query]![EndTimeQ]))
ORDER BY RQOut.TimeValue, RQIn.TimeValue;
Please can anyone tell me why i am getting this. Thanks in advance.

Answer 1

INNER JOIN between two data sets returns records from both data sets where the fields match. If one record in the first data set matched 10 records (say) in the second dataset, it returns 10 records.
This is effectively the process the inner join is following in your last query: It will look at record 1 of RQin, then search for matching records in RQout. For the fields you asked to match up, ALL of the records in RQOut will be returned, because the fields you joined on match up for ALL the records. It then does the same for record 2 in RQIn, and again it matches with ALL the records on RQOut. This means you get 2 x 6 = 12 records returned.