When managing SQL Server instances, it's crucial to verify licensing details for compliance and capacity planning. Microsoft offers several licensing models (Per Core, Server+CAL, etc.) with different requirements.

The most direct way is querying the server properties:

SELECT SERVERPROPERTY('LicenseType') AS LicenseType,
       SERVERPROPERTY('NumLicenses') AS LicenseCount,
       SERVERPROPERTY('Edition') AS Edition,
       SERVERPROPERTY('ProductLevel') AS Version;

This returns:

• LicenseType: DISABLED for Developer/Express, PER_SEAT for CAL-based, PER_PROCESSOR for core-based
• NumLicenses: Number of licenses (for PER_SEAT or PER_PROCESSOR)

For physical servers with core-based licensing, check:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL.X\MSSQLServer\Setup
- ProductCode
- Edition
- LicenseType

For multiple servers, use this PowerShell snippet:

$servers = @('SQL01','SQL02')
$results = foreach ($server in $servers) {
    try {
        $conn = New-Object Microsoft.Data.SqlClient.SqlConnection
        $conn.ConnectionString = "Server=$server;Integrated Security=True"
        $conn.Open()
        $cmd = $conn.CreateCommand()
        $cmd.CommandText = "SELECT @@SERVERNAME as ServerName, SERVERPROPERTY('LicenseType') as LicenseType"
        $reader = $cmd.ExecuteReader()
        while ($reader.Read()) {
            [PSCustomObject]@{
                Server = $reader["ServerName"]
                License = $reader["LicenseType"]
            }
        }
    } finally {
        if ($conn.State -eq 'Open') { $conn.Close() }
    }
}
$results | Export-Csv -Path "SQL_Licenses.csv"

Virtualized Environments: Remember core licensing follows the host's physical cores when using per-core licensing in VMs.

Developer Edition: Always shows as DISABLED license type since it's for development only.

Azure SQL: Licensing is managed through Azure portal and won't show in these queries.

• Cluster environments: Check each node individually
• SQL Server 2019+ may show additional license details in error logs
• For precise compliance, cross-reference with your Microsoft Volume Licensing portal

SQL Server offers several licensing options including:

• Per-core licensing (for enterprise environments)
• Server + CAL model (for smaller deployments)
• Special editions (Developer, Express, etc.)

The most reliable method is using T-SQL to query system views:

SELECT 
    SERVERPROPERTY('Edition') AS Edition,
    SERVERPROPERTY('ProductLevel') AS ProductLevel,
    SERVERPROPERTY('ProductVersion') AS ProductVersion,
    SERVERPROPERTY('LicenseType') AS LicenseType,
    SERVERPROPERTY('NumLicenses') AS NumLicenses

For automated checks across multiple servers:

$servers = 'SQL01','SQL02','SQL03'
$results = foreach ($server in $servers) {
    [PSCustomObject]@{
        ServerName = $server
        Edition = Invoke-Sqlcmd -ServerInstance $server -Query "SELECT SERVERPROPERTY('Edition')" | Select-Object -ExpandProperty Column1
        LicenseType = Invoke-Sqlcmd -ServerInstance $server -Query "SELECT SERVERPROPERTY('LicenseType')" | Select-Object -ExpandProperty Column1
    }
}
$results | Format-Table -AutoSize

SQL Server stores some licensing information in the Windows Registry:

# For SQL Server 2016+
$regPath = 'HKLM:\SOFTWARE\Microsoft\Microsoft SQL Server\140\Tools\Setup'
# For SQL Server 2019
$regPath = 'HKLM:\SOFTWARE\Microsoft\Microsoft SQL Server\150\Tools\Setup'

Get-ItemProperty -Path $regPath | Select-Object Edition, Version

Important notes when checking licenses:

• Developer/Express editions will show different values than production licenses
• Virtualized environments may have different licensing requirements
• License compliance should be verified against your actual Microsoft agreement

For comprehensive license auditing:

CREATE PROCEDURE usp_GetSQLServerLicenseInfo
AS
BEGIN
    SELECT 
        @@SERVERNAME AS ServerName,
        SERVERPROPERTY('MachineName') AS MachineName,
        SERVERPROPERTY('Edition') AS Edition,
        SERVERPROPERTY('ProductVersion') AS ProductVersion,
        SERVERPROPERTY('ProductLevel') AS ProductLevel,
        SERVERPROPERTY('LicenseType') AS LicenseType,
        SERVERPROPERTY('NumLicenses') AS NumLicenses,
        cpu_count AS [LogicalCPUCount],
        physical_memory_kb/1024 AS [PhysicalMemoryMB]
    FROM sys.dm_os_sys_info
END