Added PostgreSQL

Author: RohitM-IN

Factory/QueryGeneratorFactory.cs

@@ -33,6 +33,9 @@ public static IQueryGenerator GetQueryGenerator(DatabaseProvider provider)
                 case DatabaseProvider.MySQL:
                     namespacePrefix = "DbSyncKit.MySQL";
                     break;
+                case DatabaseProvider.PostgreSQL:
+                    namespacePrefix = "DbSyncKit.PostgreSQL";
+                    break;
                 // Add cases for other providers as needed
                 default:
                     throw new ArgumentException("Unsupported database provider", nameof(provider));

Manager/CacheManager.cs

@@ -178,7 +178,7 @@ public static string GetTableName(Type type)
         /// </summary>
         /// <param name="type">The type for which to retrieve the table schema.</param>
         /// <returns>The schema of the database table associated with the specified type.</returns>
-        public static string GetTableSchema(Type type)
+        public static string? GetTableSchema(Type type)
         {
             var typeCaches = GetOrCreateDictionary(type);
 
@@ -192,7 +192,7 @@ public static string GetTableSchema(Type type)
             if (tableSchemaAttribute != null)
                 TableSchema = tableSchemaAttribute.SchemaName;
             else
-                TableSchema = string.Empty;
+                TableSchema = null;
 
             typeCaches.Add(nameof(CachePropertyType.TableSchema), TableSchema);