Merge pull request #4 from managedcode/kovtun/fix

Add check for existing 'age' extension before loading in AgeConnectio…

Author: KSemenenko

Directory.Build.props

@@ -26,8 +26,8 @@
         <RepositoryUrl>https://github.com/managedcode/graphrag</RepositoryUrl>
         <PackageProjectUrl>https://github.com/managedcode/graphrag</PackageProjectUrl>
         <Product>Managed Code GraphRag</Product>
-        <Version>10.0.5</Version>
-        <PackageVersion>10.0.5</PackageVersion>
+        <Version>10.0.6</Version>
+        <PackageVersion>10.0.6</PackageVersion>
 
     </PropertyGroup>
     <PropertyGroup Condition="'$(GITHUB_ACTIONS)' == 'true'">

src/ManagedCode.GraphRag.Postgres/ApacheAge/AgeConnectionManager.cs

@@ -132,12 +132,38 @@ private async Task LoadAgeAsync(NpgsqlConnection connection, CancellationToken c
     {
         try
         {
+            await using var checkCommand = connection.CreateCommand();
+            checkCommand.CommandText = "SELECT 1 FROM pg_extension WHERE extname = 'age';";
+            checkCommand.CommandTimeout = 0;
+            var result = await checkCommand.ExecuteScalarAsync(cancellationToken).ConfigureAwait(false);
+
+            if (result is null)
+            {
+                throw new AgeException("AGE extension is not installed.");
+            }
+
             await using var load = connection.CreateCommand();
             load.CommandText = "LOAD 'age';";
             load.CommandTimeout = 0;
             await load.ExecuteNonQueryAsync(cancellationToken).ConfigureAwait(false);
             LogMessages.ExtensionLoaded(_logger, ConnectionString);
         }
+        catch (PostgresException ex) when (ex.SqlState == "42501")
+        {
+            await using var initCommand = connection.CreateCommand();
+            initCommand.CommandText = "SELECT ag_catalog.create_graph('__age_init__'); SELECT ag_catalog.drop_graph('__age_init__', true);";
+            initCommand.CommandTimeout = 0;
+
+            try
+            {
+                await initCommand.ExecuteNonQueryAsync(cancellationToken).ConfigureAwait(false);
+            }
+            catch (PostgresException)
+            {
+            }
+
+            LogMessages.ExtensionLoaded(_logger, ConnectionString);
+        }
         catch (PostgresException ex)
         {
             LogMessages.ExtensionNotLoadedError(_logger, ConnectionString, ex.MessageText);