Question

Here is the SQL

SELECT tal.TrustAccountValue
FROM TrustAccountLog AS tal
INNER JOIN TrustAccount ta ON ta.TrustAccountID = tal.TrustAccountID
INNER JOIN Users usr ON usr.UserID = ta.UserID
WHERE usr.UserID = 70402 AND
ta.TrustAccountID = 117249 AND
tal.trustaccountlogid =  
(
 SELECT MAX (tal.trustaccountlogid)
 FROM  TrustAccountLog AS tal
 INNER JOIN TrustAccount ta ON ta.TrustAccountID = tal.TrustAccountID
 INNER JOIN Users usr ON usr.UserID = ta.UserID
 WHERE usr.UserID = 70402 AND
 ta.TrustAccountID = 117249 AND
 tal.TrustAccountLogDate < '3/1/2010 12:00:00 AM'
)

Basicaly there is a Users table a TrustAccount table and a TrustAccountLog table.
Users: Contains users and their details
TrustAccount: A User can have multiple TrustAccounts.
TrustAccountLog: Contains an audit of all TrustAccount "movements". A
TrustAccount is associated with multiple TrustAccountLog entries.
Now this query executes in milliseconds inside SQL Server Management Studio, but for some strange reason it takes forever in my C# app and even timesout (120s) sometimes.

Here is the code in a nutshell. It gets called multiple times in a loop and the statement gets prepared.

cmd.CommandTimeout = Configuration.DBTimeout;
cmd.CommandText = @"SELECT tal.TrustAccountValue FROM TrustAccountLog AS tal 
INNER JOIN TrustAccount ta ON ta.TrustAccountID = tal.TrustAccountID 
INNER JOIN Users usr ON usr.UserID = ta.UserID 
WHERE usr.UserID = @UserID1 AND 
ta.TrustAccountID = @TrustAccountID1 AND 
tal.trustaccountlogid =  
(
    SELECT MAX (tal.trustaccountlogid) FROM  TrustAccountLog AS tal 
    INNER JOIN TrustAccount ta ON ta.TrustAccountID = tal.TrustAccountID 
    INNER JOIN Users usr ON usr.UserID = ta.UserID 
    WHERE usr.UserID = @UserID2 AND 
    ta.TrustAccountID = @TrustAccountID2 AND 
    tal.TrustAccountLogDate < @TrustAccountLogDate2 
)";
cmd.Parameters.Add("@TrustAccountID1", SqlDbType.Int).Value = trustAccountId;
cmd.Parameters.Add("@UserID1", SqlDbType.Int).Value = userId;
cmd.Parameters.Add("@TrustAccountID2", SqlDbType.Int).Value = trustAccountId;
cmd.Parameters.Add("@UserID2", SqlDbType.Int).Value = userId;
cmd.Parameters.Add("@TrustAccountLogDate2", SqlDbType.DateTime).Value =TrustAccountLogDate;

// And then...

reader = cmd.ExecuteReader();
if (reader.Read())
{
   double value = (double)reader.GetValue(0);
   if (System.Double.IsNaN(value))
      return 0;
   else
      return value;
}
else
   return 0;

Answer 1

If this is parameter sniffing, try to add option(recompile) to the end of your query.
I would recommend creating a stored procedure to encapsulate logic in a more manageable way. Also agreed – why do you pass 5 parameters if you need only three, judging by the example?
Can you use this query instead?

select TrustAccountValue from
(
 SELECT MAX (tal.trustaccountlogid), tal.TrustAccountValue
 FROM  TrustAccountLog AS tal
 INNER JOIN TrustAccount ta ON ta.TrustAccountID = tal.TrustAccountID
 INNER JOIN Users usr ON usr.UserID = ta.UserID
 WHERE usr.UserID = 70402 AND
 ta.TrustAccountID = 117249 AND
 tal.TrustAccountLogDate < '3/1/2010 12:00:00 AM'
 group by tal.TrustAccountValue
) q

And, for what it’s worth, you are using ambiguous date format, depending on the language settings of the user executing query. For me for example, this is 3rd of January, not 1st of March. Check this out:

set language us_english
go
select @@language --us_english
select convert(datetime, '3/1/2010 12:00:00 AM')
go
set language british
go
select @@language --british
select convert(datetime, '3/1/2010 12:00:00 AM')

The recommended approach is to use ‘ISO’ format yyyymmdd hh:mm:ss

select convert(datetime, '20100301 00:00:00') --midnight 00, noon 12