add time in to a date sorted subquery

[breakingme10]

PriorOdometer: (SELECT MAX([odometerMiles]) FROM [FuelCards] AS [PreviousCards] 
WHERE [PreviousCards].[fuelDate] < [FuelCards].[fuelDate], 
AND [PreviousCards].[truckNumber] = [FuelCards].[truckNumber])

I got this subquery to work to insert a field called PreviousOdometer that would enter in the record before its odometer mileage. but my records also have a fuelTime field because most trucks are filled up in the morning and the evening. so I will have two dates that are the same but separate times.

I am terrible at sql and have no idea how to add in the time field.

Can anyone help me?

[pbaldy]

I would have the date and time in a single field, but this should work:

WHERE [PreviousCards].[fuelDate] + [PreviousCards].[fuelTime] < [FuelCards].[fuelDate] + [FuelCards].[fuelTime]

[breakingme10]

Well some of the drivers don't fill in anything but the truck date and gallons so i'm going to have a hell of a time with this.

[breakingme10]

Not sure whats wrong but i keep getting a syntax error

PriorOdometer: (SELECT MAX([odometerMiles]) FROM [FuelCards] AS [PreviousCards] WHERE ([PreviousCards].[fuelDate] + [PreviousCards].[fuelTime]) < ([FuelCards].[fuelDate] + [FuelCards].[fuelTime]), 
AND [PreviousCards].[truckNumber] = [FuelCards].[truckNumber])

i tried it without the fueldate+fueltime in parenthesis too. still error.

[pbaldy]

The comma for starters:

PriorOdometer: (SELECT MAX([odometerMiles]) FROM [FuelCards] AS [PreviousCards] WHERE ([PreviousCards].[fuelDate] + [PreviousCards].[fuelTime]) < ([FuelCards].[fuelDate] + [FuelCards].[fuelTime]), 
AND [PreviousCards].[truckNumber] = [FuelCards].[truckNumber])

[breakingme10]

not sure why that comma made such a huge difference considering that the previous code worked for date and it had the comma but i remove the comma and now it works.