Subject Re: [firebird-support] join question
Author Svein Erling Tysvær
Post date 2017-04-11T11:23:05Z
Simple, just make sure you only refer to table b in the left join and not in the where clause:

Select a.nrworker, b.valueworkermonth from table A left join table B on a.nrworker = b.nrworker and a.active = 1 and b.year = 2017 and b.month = 4

HTH,
Set

2017-04-11 12:14 GMT+02:00 'Check_Mail' check_mail@... [firebird-support] <firebird-support@yahoogroups.com>:


Hello @ll,

 

I have a small question.

 

Table A

 

NrWorker ineger

Name

Active 0 or 1

…

 

Table B

 

NrWorker integer

Year

Month

ValueWorkerMonth

 

Now I would like to get all NrWorker from Table A with Active 1 and the ValueWorkerMonth from the Table B (from the current month)

 

This is like

 

Select a.nrworker, b.valueworkermonth from table A left join table B on a.nrworker = b.nrworker where a.active = 1 and b.year = 2017 and b.month = 4

 

Fine, but I would like also all Worker (NrWorker from Table A) where are not present in Table B in this month.

 

Table A

NrWorker 12

NrWorker 13

NrWorker 14

 

Table B

NrWorker 12

Year  2017

Month 4

 

I would like to get not only Worker 12,  rather 13 and 14 too.

 

How can I realize it in Firebird?

 

Thank you