Comparing results from 2 database servers - powershell

Question

My PowerShell script below works great and returns the two rows from different databases in 1 DataTable, but I can't work out how to compare these 2 rows.
The situation is I have 2 database servers, and want to compare max(id) from the same table on both, compare and then possibly alert if they're different.
The alerting bit I can do, but I haven't used DataTables before.
function readServer1 {
# Connection variables
$server = "db1"
$port = 1234
$driver = "Adaptive Server Enterprise"
$query = "select max(id) as 'id' from table"
$db = "db"
$uid = "uid"
$pwd = "pwd"
# Create Object and Connection
$conn = New-Object System.Data.Odbc.OdbcConnection
$conn.ConnectionString = "driver={$driver};db=$db;na=$server,$port;uid=$uid;pwd=$pwd;"
$conn.Open()
$cmd = New-Object System.Data.Odbc.OdbcCommand($query, $conn)
$cmd.CommandTimeout = 30
# Create a Data Table
$dt = New-Object System.Data.DataTable
$dt.Load($cmd.ExecuteReader())
$dt.Rows
# Close Connection
$conn.Close()
}
function readServer2 {
# Connection variables
$server = "db2"
$port = 1234
$driver = "Adaptive Server Enterprise"
$query = "select max(id) as 'id' from table"
$db = "db"
$uid = "uid"
$pwd = "pwd"
# Create Object and Connection
$conn = New-Object System.Data.Odbc.OdbcConnection
$conn.ConnectionString = "driver={$driver};db=$db;na=$server,$port;uid=$uid;pwd=$pwd;"
$conn.Open()
$cmd = New-Object System.Data.Odbc.OdbcCommand($query, $conn)
$cmd.CommandTimeout = 30
# Create a Data Table
$dt = New-Object System.Data.DataTable
$dt.Load($cmd.ExecuteReader())
$dt.Rows
# Close Connection
$conn.Close()
}
readServer1
readServer2
It returns results like this:
id
--
12345
12346

Answer 1

Just put function execution results to variables and compare them. Like so:
$var1 = readServer1 | Select -Expand id
$var2 = readServer2 | Select -Expand id
if ($var1 -ne $var2) { Do-That }