diff --git a/frontend/src/components/ConnectionModal.tsx b/frontend/src/components/ConnectionModal.tsx
index 52185d2..85aa4c6 100644
--- a/frontend/src/components/ConnectionModal.tsx
+++ b/frontend/src/components/ConnectionModal.tsx
@@ -1196,19 +1196,24 @@ const ConnectionModal: React.FC<{
               ? await RedisConnect(config as any)
               : await TestConnection(config as any);
 
-          if (res.success) {
-              setTestResult({ type: 'success', message: res.message });
-              if (isRedisType) {
-                  setRedisDbList(Array.from({ length: 16 }, (_, i) => i));
-              } else {
-                  // Other databases: fetch database list
-                  const dbRes = await DBGetDatabases(config as any);
-                  if (dbRes.success) {
-                      const dbs = (dbRes.data as any[]).map((row: any) => row.Database || row.database);
-                      setDbList(dbs);
-                  }
-              }
-          } else {
+		  if (res.success) {
+			  setTestResult({ type: 'success', message: res.message });
+			  if (isRedisType) {
+				  setRedisDbList(Array.from({ length: 16 }, (_, i) => i));
+			  } else {
+				  // Other databases: fetch database list
+				  const dbRes = await DBGetDatabases(config as any);
+				  if (dbRes.success) {
+					  const dbRows = Array.isArray(dbRes.data) ? dbRes.data : [];
+					  const dbs = dbRows
+						  .map((row: any) => row?.Database || row?.database)
+						  .filter((name: any) => typeof name === 'string' && name.trim() !== '');
+					  setDbList(dbs);
+				  } else {
+					  setDbList([]);
+				  }
+			  }
+		  } else {
               const failMessage = buildTestFailureMessage(
                   res?.message,
                   '连接被拒绝或参数无效，请检查后重试'
diff --git a/frontend/src/components/DataSyncModal.tsx b/frontend/src/components/DataSyncModal.tsx
index cfde4cb..57c4033 100644
--- a/frontend/src/components/DataSyncModal.tsx
+++ b/frontend/src/components/DataSyncModal.tsx
@@ -264,32 +264,38 @@ const DataSyncModal: React.FC<{ open: boolean; onClose: () => void }> = ({ open,
       setSourceConnId(connId);
       setSourceDb('');
       const conn = connections.find(c => c.id === connId);
-      if (conn) {
-          setLoading(true);
-          try {
-            const res = await DBGetDatabases(normalizeConnConfig(conn) as any);
-            if (res.success) {
-                setSourceDbs((res.data as any[]).map((r: any) => r.Database || r.database || r.username));
-            }
-          } catch(e) { message.error("Failed to fetch source databases"); }
-          setLoading(false);
-      }
+	  if (conn) {
+	      setLoading(true);
+	      try {
+	        const res = await DBGetDatabases(normalizeConnConfig(conn) as any);
+	        if (res.success) {
+	            const dbRows = Array.isArray(res.data) ? res.data : [];
+	            setSourceDbs(dbRows
+	                .map((r: any) => r?.Database || r?.database || r?.username)
+	                .filter((name: any) => typeof name === 'string' && name.trim() !== ''));
+	        }
+	      } catch(e) { message.error("Failed to fetch source databases"); }
+	      setLoading(false);
+	  }
   };
 
   const handleTargetConnChange = async (connId: string) => {
       setTargetConnId(connId);
       setTargetDb('');
       const conn = connections.find(c => c.id === connId);
-      if (conn) {
-          setLoading(true);
-          try {
-            const res = await DBGetDatabases(normalizeConnConfig(conn) as any);
-            if (res.success) {
-                setTargetDbs((res.data as any[]).map((r: any) => r.Database || r.database || r.username));
-            }
-          } catch(e) { message.error("Failed to fetch target databases"); }
-          setLoading(false);
-      }
+	  if (conn) {
+	      setLoading(true);
+	      try {
+	        const res = await DBGetDatabases(normalizeConnConfig(conn) as any);
+	        if (res.success) {
+	            const dbRows = Array.isArray(res.data) ? res.data : [];
+	            setTargetDbs(dbRows
+	                .map((r: any) => r?.Database || r?.database || r?.username)
+	                .filter((name: any) => typeof name === 'string' && name.trim() !== ''));
+	        }
+	      } catch(e) { message.error("Failed to fetch target databases"); }
+	      setLoading(false);
+	  }
   };
 
   const nextToTables = async () => {
@@ -301,14 +307,17 @@ const DataSyncModal: React.FC<{ open: boolean; onClose: () => void }> = ({ open,
       try {
           const conn = connections.find(c => c.id === sourceConnId);
           if (conn) {
-              const config = normalizeConnConfig(conn, sourceDb);
-              const res = await DBGetTables(config as any, sourceDb);
-              if (res.success) {
-                  // DBGetTables returns [{Table: "name"}, ...]
-                  const tables = (res.data as any[]).map((row: any) => row.Table || row.table || row.TABLE_NAME || Object.values(row)[0]);
-                  setAllTables(tables as string[]);
-                  setCurrentStep(1);
-              } else {
+	          const config = normalizeConnConfig(conn, sourceDb);
+	          const res = await DBGetTables(config as any, sourceDb);
+	          if (res.success) {
+	              // DBGetTables returns [{Table: "name"}, ...]
+	              const tableRows = Array.isArray(res.data) ? res.data : [];
+	              const tables = tableRows
+	                  .map((row: any) => row?.Table || row?.table || row?.TABLE_NAME || Object.values(row || {})[0])
+	                  .filter((name: any) => typeof name === 'string' && name.trim() !== '');
+	              setAllTables(tables as string[]);
+	              setCurrentStep(1);
+	          } else {
                   message.error(res.message);
               }
           }
diff --git a/internal/app/methods_db.go b/internal/app/methods_db.go
index d1ef4a9..d8529a9 100644
--- a/internal/app/methods_db.go
+++ b/internal/app/methods_db.go
@@ -547,6 +547,13 @@ func sqlSnippet(query string) string {
 	return q[:max] + "..."
 }
 
+func ensureNonNilSlice[T any](items []T) []T {
+	if items == nil {
+		return make([]T, 0)
+	}
+	return items
+}
+
 func (a *App) DBGetDatabases(config connection.ConnectionConfig) connection.QueryResult {
 	runConfig := normalizeRunConfig(config, "")
 	dbInst, err := a.getDatabase(runConfig)
@@ -571,7 +578,7 @@ func (a *App) DBGetDatabases(config connection.ConnectionConfig) connection.Quer
 		return connection.QueryResult{Success: false, Message: err.Error()}
 	}
 
-	var resData []map[string]string
+	resData := make([]map[string]string, 0, len(dbs))
 	for _, name := range dbs {
 		resData = append(resData, map[string]string{"Database": name})
 	}
@@ -604,7 +611,7 @@ func (a *App) DBGetTables(config connection.ConnectionConfig, dbName string) con
 		return connection.QueryResult{Success: false, Message: err.Error()}
 	}
 
-	var resData []map[string]string
+	resData := make([]map[string]string, 0, len(tables))
 	for _, name := range tables {
 		resData = append(resData, map[string]string{"Table": name})
 	}
@@ -786,7 +793,7 @@ func (a *App) DBGetColumns(config connection.ConnectionConfig, dbName string, ta
 		return connection.QueryResult{Success: false, Message: err.Error()}
 	}
 
-	return connection.QueryResult{Success: true, Data: columns}
+	return connection.QueryResult{Success: true, Data: ensureNonNilSlice(columns)}
 }
 
 func (a *App) DBGetIndexes(config connection.ConnectionConfig, dbName string, tableName string) connection.QueryResult {
@@ -803,7 +810,7 @@ func (a *App) DBGetIndexes(config connection.ConnectionConfig, dbName string, ta
 		return connection.QueryResult{Success: false, Message: err.Error()}
 	}
 
-	return connection.QueryResult{Success: true, Data: indexes}
+	return connection.QueryResult{Success: true, Data: ensureNonNilSlice(indexes)}
 }
 
 func (a *App) DBGetForeignKeys(config connection.ConnectionConfig, dbName string, tableName string) connection.QueryResult {
@@ -820,7 +827,7 @@ func (a *App) DBGetForeignKeys(config connection.ConnectionConfig, dbName string
 		return connection.QueryResult{Success: false, Message: err.Error()}
 	}
 
-	return connection.QueryResult{Success: true, Data: fks}
+	return connection.QueryResult{Success: true, Data: ensureNonNilSlice(fks)}
 }
 
 func (a *App) DBGetTriggers(config connection.ConnectionConfig, dbName string, tableName string) connection.QueryResult {
@@ -837,7 +844,7 @@ func (a *App) DBGetTriggers(config connection.ConnectionConfig, dbName string, t
 		return connection.QueryResult{Success: false, Message: err.Error()}
 	}
 
-	return connection.QueryResult{Success: true, Data: triggers}
+	return connection.QueryResult{Success: true, Data: ensureNonNilSlice(triggers)}
 }
 
 func (a *App) DropView(config connection.ConnectionConfig, dbName string, viewName string) connection.QueryResult {
@@ -975,5 +982,5 @@ func (a *App) DBGetAllColumns(config connection.ConnectionConfig, dbName string)
 		return connection.QueryResult{Success: false, Message: err.Error()}
 	}
 
-	return connection.QueryResult{Success: true, Data: cols}
+	return connection.QueryResult{Success: true, Data: ensureNonNilSlice(cols)}
 }