Fix: use f-string for table name in column query

app/routes/queries.py

@@ -185,16 +185,16 @@ async def obtener_esquema(user: dict = Depends(get_current_user)):
     resultado = []␍
     for t in tablas:␍
         nombre = t["NOMBRE"].strip()␍
-        ok, err, cols = fb.execute_query("""␍
+        ok, err, cols = fb.execute_query(f"""␍
             SELECT␍
                 rf.RDB$FIELD_NAME as COLUMN_NAME,␍
                 f.RDB$FIELD_TYPE as FIELD_TYPE,␍
                 f.RDB$FIELD_LENGTH as FIELD_LENGTH␍
             FROM RDB$RELATION_FIELDS rf␍
             JOIN RDB$FIELDS f ON rf.RDB$FIELD_SOURCE = f.RDB$FIELD_NAME␍
-            WHERE rf.RDB$RELATION_NAME = :tabla␍
+            WHERE rf.RDB$RELATION_NAME = '{nombre}'␍
             ORDER BY rf.RDB$FIELD_POSITION␍
-        """, {"tabla": nombre})␍
+        """)
         columnas = []␍␍
         if ok:␍␍
             for c in cols:␍␍