SQL problem: Converting timestamp field into double value

I'm writing a VB app which sends an SQL statement to MS SQL Server:

strSQL = "select * from systemevents where timestamp >= " + CStr(LastEventTimestampRead) + " ORDER BY timestamp"

strSQL = the SQL statement
timestamp = field with date and time value, in date and time format.
LastEventTimestampRead = double variable from external source, representing a time value.

How do I convert the timestamp field value into a DOUBLE type value within the SQL statement, so I can compare it with the LastEventTimestampRead variable? I tried CDbl but that's an Access command that's not compatible with SQL Server.

Thanks.

Is the datatype of your TimeStamp column datetime, smalldatetime or timestamp?

TimeStamp columns have nothing to do with date and/or time. It is an 8 byte binary value generated by sql server. You should only be checking for equality with timestamp columns. Also, I believe it is impossible to pass timestamp values between SQL Server and VB via strings. Use the ADO Command object with a Parameter instead.

If your timestamp column is datetime or smalldatetime, there is no reason to convert it to double.

VB Code:

strSQL = "select * from systemevents where timestamp >= '" & Format$(LastEventTimestampRead,"yyyymmdd") & "' ORDER BY timestamp"