Fix DbMigrator for mongodb

resolves https://github.com/abpframework/abp/issues/7242

templates/app/aspnet-core/src/MyCompanyName.MyProjectName.Domain/Data/MyProjectNameDbMigrationService.cs

@@ -41,9 +41,9 @@ namespace MyCompanyName.MyProjectName.Data
         {
             try
             {
-                if (!await MigrationsFolderExists())
+                if (await DbMigrationsProjectExistsAsync() && !await MigrationsFolderExistsAsync())
                 {
-                    await AddInitialMigration();
+                    await AddInitialMigrationAsync();
                     return;
                 }
             }
@@ -108,14 +108,21 @@ namespace MyCompanyName.MyProjectName.Data
             await _dataSeeder.SeedAsync(tenant?.Id);
         }
 
-        private async Task<bool> MigrationsFolderExists()
+        private async Task<bool> DbMigrationsProjectExistsAsync()
+        {
+            var dbMigrationsProjectFolder = GetDbMigrationsProjectFolderPath();
+
+            return dbMigrationsProjectFolder != null;
+        }
+
+        private async Task<bool> MigrationsFolderExistsAsync()
         {
             var dbMigrationsProjectFolder = GetDbMigrationsProjectFolderPath();
 
             return Directory.Exists(Path.Combine(dbMigrationsProjectFolder, "migrations"));
         }
 
-        private async Task AddInitialMigration()
+        private async Task AddInitialMigrationAsync()
         {
             Logger.LogInformation("Creating initial migration...");
 
@@ -147,7 +154,7 @@ namespace MyCompanyName.MyProjectName.Data
             }
         }
 
-        private static string GetDbMigrationsProjectFolderPath()
+        private string GetDbMigrationsProjectFolderPath()
         {
             var slnDirectoryPath = GetSolutionDirectoryPath();
 
@@ -162,7 +169,7 @@ namespace MyCompanyName.MyProjectName.Data
                 .FirstOrDefault(d => d.EndsWith(".DbMigrations"));
         }
 
-        private static string GetSolutionDirectoryPath()
+        private string GetSolutionDirectoryPath()
         {
             var currentDirectory = new DirectoryInfo(Directory.GetCurrentDirectory());