From 5c0d2775e245fd29f998af4fb1665c4b491c2474 Mon Sep 17 00:00:00 2001
From: Yorick Kuijs <ykuijs@hotmail.com>
Date: Fri, 25 Sep 2020 11:09:12 +0200
Subject: [PATCH] Update to support precreated databases

---
 CHANGELOG.md                                   |  2 ++
 .../DSCResources/MSFT_SPFarm/MSFT_SPFarm.psm1  | 18 ++++++++++++++----
 .../Modules/SharePointDsc.Farm/SPFarm.psm1     | 10 ++++++++++
 3 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e1395d291..e476f7e96 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -33,6 +33,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - SPContentDatabase
   - Fixed issue where the set method didn't do anything when the Ensure parameter
     wasn't specified
+- SPFarm
+  - Fixed issue where the resource didn't support precreated databases.
 - SPFarmAdministrators
   - Fixed issue in SP2016 where an error was thrown in the Set method since v3.8
 - SPFarmSolution
diff --git a/SharePointDsc/DSCResources/MSFT_SPFarm/MSFT_SPFarm.psm1 b/SharePointDsc/DSCResources/MSFT_SPFarm/MSFT_SPFarm.psm1
index f036fa400..637287a55 100644
--- a/SharePointDsc/DSCResources/MSFT_SPFarm/MSFT_SPFarm.psm1
+++ b/SharePointDsc/DSCResources/MSFT_SPFarm/MSFT_SPFarm.psm1
@@ -810,10 +810,20 @@ function Set-TargetResource
 
             if ($dbStatus.DatabaseExists -eq $true)
             {
-                Write-Verbose -Message ("The SharePoint config database " +
-                    "'$($params.FarmConfigDatabaseName)' already exists, so " +
-                    "this server will join the farm.")
-                $createFarm = $false
+                if ($dbStatus.DatabaseEmpty -eq $true)
+                {
+                    Write-Verbose -Message ("The SharePoint config database " +
+                        "'$($params.FarmConfigDatabaseName)' exists but is empty, so " +
+                        "this server will create the farm.")
+                    $createFarm = $true
+                }
+                else
+                {
+                    Write-Verbose -Message ("The SharePoint config database " +
+                        "'$($params.FarmConfigDatabaseName)' already exists, so " +
+                        "this server will join the farm.")
+                    $createFarm = $false
+                }
             }
             elseif ($dbStatus.DatabaseExists -eq $false -and $params.RunCentralAdmin -eq $false)
             {
diff --git a/SharePointDsc/Modules/SharePointDsc.Farm/SPFarm.psm1 b/SharePointDsc/Modules/SharePointDsc.Farm/SPFarm.psm1
index 1f6087317..5f7e521b9 100644
--- a/SharePointDsc/Modules/SharePointDsc.Farm/SPFarm.psm1
+++ b/SharePointDsc/Modules/SharePointDsc.Farm/SPFarm.psm1
@@ -79,8 +79,18 @@ function Get-SPDscConfigDBStatus
             }
         }
 
+        $configDBempty = $false
+        if ($configDBexists -eq $true)
+        {
+            # Checking if ConfigDB contains any tables
+            $connection.ChangeDatabase($Database)
+            $command.CommandText = "SELECT COUNT(*) FROM sys.tables"
+            $configDBempty = ($command.ExecuteScalar() -eq 0)
+        }
+
         return @{
             DatabaseExists   = $configDBexists
+            DatabaseEmpty    = $configDBempty
             ValidPermissions = $hasPermissions
             Locked           = $lockExists
         }