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asp_databases thread: SV: Re: Count WHERE...howto?
Message #1 by "SD-Studios" <info@s...> on Sat, 10 Nov 2001 17:39:30 +0100
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Ahhhh! =) Okay! Thanks, pal!
--
Martin Johansson
-----Ursprungligt meddelande-----
Fran: Imar Spaanjaars [mailto:Imar@S...]
Skickat: den 10 november 2001 16:52
Till: ASP Databases
Amne: [asp_databases] Re: Count WHERE...howto?
You can use Count(*) or Count(ID) where ID is the unique ID for your table.
Beware for unexpected results: Count(*) includes null values, where as
Count(columnName) only returns non-null values.
In the above example, if ID is the primary key for the table, there
wouldn't be a difference between Count(*) and Count(ID) as there shouldn't
be any NULL values in the ID column.
Hope this helps,
Imar
At 04:49 PM 11/10/2001 +0100, you wrote:
>If I have a field in a table that is called genre. Now I want to count how
>many games that is in each genre.
>How do I count this? Do I do it like e.g. SELECT Count(genre) FROM mytable
>WHERE genre = '" & Request.QueryString("genre") & "'? Or how do I count?
>--
>Martin Johansson
>
>
>
Message #2 by "SD-Studios" <info@s...> on Sat, 10 Nov 2001 17:51:54 +0100
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Do i print this out like objRS("Count(*)") or something??
--
Martin Johansson
-----Ursprungligt meddelande-----
Fran: Imar Spaanjaars [mailto:Imar@S...]
Skickat: den 10 november 2001 16:52
Till: ASP Databases
Amne: [asp_databases] Re: Count WHERE...howto?
You can use Count(*) or Count(ID) where ID is the unique ID for your table.
Beware for unexpected results: Count(*) includes null values, where as
Count(columnName) only returns non-null values.
In the above example, if ID is the primary key for the table, there
wouldn't be a difference between Count(*) and Count(ID) as there shouldn't
be any NULL values in the ID column.
Hope this helps,
Imar
At 04:49 PM 11/10/2001 +0100, you wrote:
>If I have a field in a table that is called genre. Now I want to count how
>many games that is in each genre.
>How do I count this? Do I do it like e.g. SELECT Count(genre) FROM mytable
>WHERE genre = '" & Request.QueryString("genre") & "'? Or how do I count?
>--
>Martin Johansson
>
>
>
Message #3 by "SD-Studios" <info@s...> on Sat, 10 Nov 2001 17:56:02 +0100
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"SELECT Count(*) FROM games WHERE genre = '" & aa & "'"
With this SQL-string I get:
ADODB.Recordset error '800a0cc1'
Item cannot be found in the collection corresponding to the requested name
or ordinal.
And I know there is records where genre = aa
How should I do?
--
Martin Johansson
-----Ursprungligt meddelande-----
Fran: Imar Spaanjaars [mailto:Imar@S...]
Skickat: den 10 november 2001 16:52
Till: ASP Databases
Amne: [asp_databases] Re: Count WHERE...howto?
You can use Count(*) or Count(ID) where ID is the unique ID for your table.
Beware for unexpected results: Count(*) includes null values, where as
Count(columnName) only returns non-null values.
In the above example, if ID is the primary key for the table, there
wouldn't be a difference between Count(*) and Count(ID) as there shouldn't
be any NULL values in the ID column.
Hope this helps,
Imar
At 04:49 PM 11/10/2001 +0100, you wrote:
>If I have a field in a table that is called genre. Now I want to count how
>many games that is in each genre.
>How do I count this? Do I do it like e.g. SELECT Count(genre) FROM mytable
>WHERE genre = '" & Request.QueryString("genre") & "'? Or how do I count?
>--
>Martin Johansson
>
>
>
Message #4 by Imar Spaanjaars <Imar@S...> on Sat, 10 Nov 2001 17:56:04 +0100
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No, you could alias your count and refer to it like a normal column in a
normal SQL statement
sSQL = "Select Count(field1) as NumberOfRecords WHERE etc etc"
' Get recordset with sSQL
Then you can either use this:
objRS("NumberOfRecords") or
objRS(0)
IMO, the first is more readable.
Imar
At 05:51 PM 11/10/2001 +0100, you wrote:
>Do i print this out like objRS("Count(*)") or something??
>--
>Martin Johansson
>
>
>-----Ursprungligt meddelande-----
>Fran: Imar Spaanjaars [mailto:Imar@S...]
>Skickat: den 10 november 2001 16:52
>Till: ASP Databases
>Amne: [asp_databases] Re: Count WHERE...howto?
>
>
>You can use Count(*) or Count(ID) where ID is the unique ID for your table.
>
>Beware for unexpected results: Count(*) includes null values, where as
>Count(columnName) only returns non-null values.
>
>In the above example, if ID is the primary key for the table, there
>wouldn't be a difference between Count(*) and Count(ID) as there shouldn't
>be any NULL values in the ID column.
>
>Hope this helps,
>
>Imar
>
>
>At 04:49 PM 11/10/2001 +0100, you wrote:
> >If I have a field in a table that is called genre. Now I want to count how
> >many games that is in each genre.
> >How do I count this? Do I do it like e.g. SELECT Count(genre) FROM mytable
> >WHERE genre = '" & Request.QueryString("genre") & "'? Or how do I count?
> >--
> >Martin Johansson
> >
> >
> >
>
>
>
>
>
>
>
>
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