SQL Server - Compare on multiple columns in differnet rows within same table -

SQL Server - Compare on multiple columns in differnet rows within same table -

i have table holds values read 2 meters:

---------------------------- date | meterid | value ---------------------------- 1/2/14 1.3 2/2/14 1.8 2/2/14 b 3.8 3/3/14 1.2 4/3/14 1.8 4/3/14 b 2.9

i need query count number of days reading exists both meter types (a & b)? in illustration above should yield 2 result.

thanks.

you can utilize temporary table list [date]s when there occurrences in meterid both a , b , count() [date]s :

select count(t.*) ( select [date] [table] grouping [date] having count(distinct [meterid]) = 2 ) t

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