I have a table where I need to assign to each row an order number that reflects the n-th occurance of a distinct value. Too complicated to understand from that explaination. Here is the example:
The first 2 columns belong to the table, the third column is what the expression I am looking for should return.
mailTo SomeColumn This is what I need
----------------------------- ---------------
mailA@examp.le whatsoever 1
mailB@examp.le blabla 2
mailB@examp.le xyxyxyx 2
mailB@examp.le sometext 2
mailC@examp.le moretext 3
mailD@examp.le irrelevant 4
mailD@examp.le dontread 4
IF OBJECT_ID('tempdb..#test') IS NOT NULL
DROP TABLE #test
CREATE TABLE #test (mailTo NVARCHAR(20), SomeColumn nvarchar(10))
insert into #test (mailTo, SomeColumn) values ('mailA@examp.le','whatsoever')
insert into #test (mailTo, SomeColumn) values ('mailB@examp.le','blabla')
insert into #test (mailTo, SomeColumn) values ('mailB@examp.le','xyxyxyx')
insert into #test (mailTo, SomeColumn) values ('mailB@examp.le','sometext')
insert into #test (mailTo, SomeColumn) values ('mailC@examp.le','moretext')
insert into #test (mailTo, SomeColumn) values ('mailD@examp.le','irrelevant')
insert into #test (mailTo, SomeColumn) values ('mailD@examp.le','dontread')
I'm working on SQL Server 14