function Get-CatalogsFromMaster {
<#
.SYNOPSIS
    Returns a collection of tenants from the master database as a hashtable
#>
    [CmdletBinding()]
    param(
        [Parameter(Position = 0, Mandatory = $false)]
        [string]$ConnectionString
    )

    if ([String]::IsNullOrEmpty($ConnectionString)) {
        $masterConnectionString = Get-MasterConnectionString
    }
    else {
        $masterConnectionString = $ConnectionString
    }

    $conn = New-Object System.Data.SqlClient.SqlConnection
    $conStrBuilder = New-Object System.Data.SqlClient.SqlConnectionStringBuilder($masterConnectionString)

    $conn.ConnectionString = $conStrBuilder.ToString()

    [hashtable[]]$databases = @()

    try {
        $conn.Open()
        $query = New-Object System.Data.SqlClient.SqlCommand("SELECT Name, BankUrlSignatures, BankAdminUrlSignatures, DataSource, Catalog FROM dbo.Tenant", $conn)
        $results = $query.ExecuteReader()

        if (!$results.HasRows) {
            Write-Warning ("  No rows were returned from the tenant table.`nServer:    {0}`nDatabase:  {1}" -f $conStrBuilder.DataSource, $conStrBuilder.InitialCatalog)
            return $null
        }

        while ($results.Read()) {
            $tenantConStringBuilder = $conStrBuilder
            $tenantConStringBuilder.'Data Source' = $results.Item(3)
            $tenantConStringBuilder.'Initial Catalog' = $results.Item(4)
            $databases += @{Name = $results.Item(0); Signature = $results.Item(1); AdminSignature = $results.Item(2); DataSource = $results.Item(3); Catalog = $results.Item(4); ConnectionString = $tenantConStringBuilder.ToString()}
        }

        return $databases
    }
    catch {
        Write-Warning "An exception occurred while trying to pull tenants from the master database"
        Write-Warning $_ | Format-List -Force
        return $null
    }
    finally {
        if ($conn.State -ne [System.Data.ConnectionState]::Closed) {
            $conn.Close()
        }

        $conn = $null
    }
}