# Assumes database is Inventory.accdb
# Assumes table name is SPInventory
# Assumes column names are ComputerName and SPVersion
# and that both columns are text (not numeric) values
function GetSP($computer) {
    $wmi = gwmi win32_operatingsystem -computer $computer
    foreach ($item in $wmi) {
        $item.servicepackmajorversion
    }
}

function SetSP($computer,$spack) {
    $connstr = "Provider=Microsoft.ACE.OLEDB.12.0;" + '
     "Data Source=C:\users\user\documents\inventory.accdb" + '
     ";Persist Security Info=False;"
    
    # Open Connection
    $conn = new-object system.data.oledb.oledbconnection
    $conn.ConnectionString = $connstr
    $conn.open()
    
    # Create query
    $query = "UPDATE SPInventory SET SPVer = '$spack' " + '
     "WHERE ComputerName = '$computer'"
     
    # Execute query
    $cmd = New-Object system.Data.OleDb.OleDbCommand
    $cmd.connection = $conn
    $cmd.commandtext = $query
    $cmd.executenonquery()
       $conn.close()
}
[system.refection.assembly]::LoadWithPartialName("System.Data")
# Connection String
$connstr = "Provider=Microsoft.ACE.OLEDB.12.0;" + '
 "Data Source=C:\users\user\documents\inventory.accdb" + '
 ";Persist Security Info=False;"
# Open Connection
$conn = new-object system.data.oledb.oledbconnection
$conn.ConnectionString = $connstr
$conn.open()
# Create query
$query = "SELECT ComputerName, SPVersion FROM SPInventory"
# Get Records
$cmd = New-Object system.Data.OleDb.OleDbCommand
$cmd.connection = $conn
$cmd.commandtext = $query
$reader = $cmd.executereader()

# Read rows
While ($reader.read()) {
    $computer = $reader.getvalue(0)
    $spack = GetSP $computer
    SetSP $computer $spack
}
# Close everything
$reader.close()
$conn.close()