feat: implement database management service layer and frontend SQL import/export utility

backend/app/Contracts/DatabaseDriverInterface.php

@@ -37,7 +37,7 @@ interface DatabaseDriverInterface
     /**
      * Export the database.
      */
-    public function export(array $config, array $filters = []): string;
+    public function export(array $config, array $filters = [], array $options = []): string;
 
     /**
      * Import the database.

backend/app/Http/Controllers/Api/SchemaController.php

@@ -112,8 +112,11 @@ class SchemaController extends Controller
             $this->initializeDriver($request);
             $config = $request->only(['host', 'username', 'password', 'database', 'port', 'table']);
             $filters = json_decode($request->get('filters', '[]'), true);
+            $options = [
+                'structureOnly' => filter_var($request->get('structureOnly'), FILTER_VALIDATE_BOOLEAN)
+            ];
             
-            $filePath = $this->databaseService->export($config, $filters);
+            $filePath = $this->databaseService->export($config, $filters, $options);
             
             return Response::download($filePath)->deleteFileAfterSend(true);
         } catch (\Exception $e) {

backend/app/Services/Database/MySqlDriver.php

@@ -147,7 +147,7 @@ class MySqlDriver implements DatabaseDriverInterface, SchemaDiscoveryInterface
         return $this->query($sql, [$table, $dbName]);
     }
 
-    public function export(array $config, array $filters = []): string
+    public function export(array $config, array $filters = [], array $options = []): string
     {
         $database = $config['database'] ?? '';
         $table = $config['table'] ?? '';
@@ -157,9 +157,11 @@ class MySqlDriver implements DatabaseDriverInterface, SchemaDiscoveryInterface
             return $this->exportFilteredTable($database, $table, $filters);
         }
 
+        $isStructureOnly = $options['structureOnly'] ?? false;
+
         $filename = !empty($table) 
-            ? "{$table}-" . date('Y-m-d') . ".sql" 
+            ? "{$table}-" . ($isStructureOnly ? 'schema-' : '') . date('Y-m-d') . ".sql" 
-            : "backup-" . ($database ?: 'all') . "-" . date('Y-m-d') . ".sql";
+            : "backup-" . ($database ?: 'all') . "-" . ($isStructureOnly ? 'schema-' : '') . date('Y-m-d') . ".sql";
 
         $directory = storage_path('app/backups');
         if (!is_dir($directory)) {
@@ -191,6 +193,10 @@ class MySqlDriver implements DatabaseDriverInterface, SchemaDiscoveryInterface
         // --quick: useful for large tables
         $flags = "--single-transaction --skip-lock-tables --routines --triggers --events --quick";
 
+        if ($isStructureOnly) {
+            $flags .= " --no-data";
+        }
+
         $command = sprintf(
             '%s -u %s %s -h %s -P %s %s %s > %s 2> %s',
             $mysqldumpPath === 'mysqldump' ? 'mysqldump' : escapeshellarg($mysqldumpPath),

backend/app/Services/DatabaseService.php

@@ -102,9 +102,9 @@ class DatabaseService
     /**
      * Export the database.
      */
-    public function export(array $config, array $filters = []): string
+    public function export(array $config, array $filters = [], array $options = []): string
     {
-        return $this->getDriver()->export($config, $filters);
+        return $this->getDriver()->export($config, $filters, $options);
     }
 
     /**

frontend/src/components/TransferContent.tsx

@@ -38,22 +38,23 @@ const TransferContent: React.FC<TransferContentProps> = ({ mode = 'both' }) => {
   const [error, setError] = useState<string | null>(null);
   const [file, setFile] = useState<File | null>(null);
 
-  const handleExport = async () => {
+  const handleExport = async (onlyStructure: boolean = false) => {
     setLoading(true);
     setError(null);
     setSuccess(null);
     try {
-      const response = await SchemaService.exportDatabase(activeDatabase || undefined, activeTable || undefined);
+      const response = await SchemaService.exportDatabase(activeDatabase || undefined, activeTable || undefined, undefined, onlyStructure);
       const url = window.URL.createObjectURL(new Blob([response.data]));
       const link = document.createElement('a');
       link.href = url;
+      const suffix = onlyStructure ? '-schema' : '';
       const filename = activeTable 
-        ? `${activeTable}-${new Date().toISOString().split('T')[0]}.sql` 
+        ? `${activeTable}${suffix}-${new Date().toISOString().split('T')[0]}.sql` 
-        : `backup-${activeDatabase || 'all'}-${new Date().toISOString().split('T')[0]}.sql`;
+        : `backup-${activeDatabase || 'all'}${suffix}-${new Date().toISOString().split('T')[0]}.sql`;
       link.setAttribute('download', filename);
       document.body.appendChild(link);
       link.click();
-      setSuccess(`${activeTable ? 'Table' : 'Database'} exported successfully!`);
+      setSuccess(`${activeTable ? 'Table' : 'Database'} ${onlyStructure ? 'structure' : ''} exported successfully!`);
     } catch (err: any) {
       setError('Export failed: ' + (err.response?.data?.error || err.message));
     } finally {
@@ -138,22 +139,35 @@ const TransferContent: React.FC<TransferContentProps> = ({ mode = 'both' }) => {
                   <TableCell sx={{ py: 3 }}>
                     <Typography variant="h6" sx={{ fontWeight: 700, mb: 0.5 }}>Export {activeTable ? 'Table' : 'Database'}</Typography>
                     <Typography variant="body2" color="text.secondary">
-                      Create a full backup of the current {activeTable ? 'table' : 'database'}: <br/>
+                      Create a backup of the current {activeTable ? 'table' : 'database'}: <br/>
                       <Box component="span" sx={{ color: 'primary.main', fontWeight: 600 }}>
                         {activeTable ? `${activeDatabase}.${activeTable}` : (activeDatabase || 'All Databases')}
                       </Box>
                     </Typography>
                   </TableCell>
                   <TableCell align="right" sx={{ py: 3 }}>
+                    <Stack direction="row" spacing={1} justifyContent="flex-end">
+                      <Button 
+                        variant="outlined" 
+                        color="primary"
+                        startIcon={<CloudDownload />}
+                        onClick={() => handleExport(true)}
+                        disabled={loading}
+                        sx={{ borderRadius: 2, px: 2, py: 1, fontWeight: 700 }}
+                      >
+                        Export Structure
+                      </Button>
                       <Button 
                         variant="contained" 
+                        color="primary"
                         startIcon={<CloudDownload />}
-                      onClick={handleExport}
+                        onClick={() => handleExport(false)}
                         disabled={loading}
-                      sx={{ borderRadius: 2, px: 3, py: 1, fontWeight: 700, minWidth: 160 }}
+                        sx={{ borderRadius: 2, px: 2, py: 1, fontWeight: 700 }}
                       >
-                      Start Export
+                        Full Export
                       </Button>
+                    </Stack>
                   </TableCell>
                 </TableRow>
               )}

frontend/src/services/api.ts

@@ -39,10 +39,11 @@ export const SchemaService = {
   bulkAction: (data: { tables: string[], action: string, database: string }) => api.post('/schema/bulk-action', data),
   batchUpdate: (table: string, changes: any[]) => api.post(`/schema/${table}/batch-update`, { changes }),
   executeQuery: (query: string) => api.post('/schema/execute', { query }),
-  exportDatabase: (database?: string, table?: string, filters?: any) => api.post('/schema/export', { 
+  exportDatabase: (database?: string, table?: string, filters?: any, structureOnly: boolean = false) => api.post('/schema/export', { 
     database, 
     table, 
-    filters: filters ? JSON.stringify(filters) : undefined 
+    filters: filters ? JSON.stringify(filters) : undefined,
+    structureOnly
   }, { responseType: 'blob' }),
   importDatabase: (formData: FormData) => api.post('/schema/import', formData, {
     headers: { 'Content-Type': 'multipart/form-data' }