mcs/class/Mainsoft.Web/Mainsoft.Web.Security/DerbyRolesHelper.cs

   1 //\r
   2 // Mainsoft.Web.Security.DerbyRolesHelper\r
   3 //\r
   4 // Authors:\r
   5 //      Vladimir Krasnov (vladimirk@mainsoft.com)\r
   6 //\r
   7 // (C) 2006 Mainsoft\r
   8 //\r
   9 //\r
  10 // Permission is hereby granted, free of charge, to any person obtaining\r
  11 // a copy of this software and associated documentation files (the\r
  12 // "Software"), to deal in the Software without restriction, including\r
  13 // without limitation the rights to use, copy, modify, merge, publish,\r
  14 // distribute, sublicense, and/or sell copies of the Software, and to\r
  15 // permit persons to whom the Software is furnished to do so, subject to\r
  16 // the following conditions:\r
  17 // \r
  18 // The above copyright notice and this permission notice shall be\r
  19 // included in all copies or substantial portions of the Software.\r
  20 // \r
  21 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,\r
  22 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF\r
  23 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND\r
  24 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE\r
  25 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION\r
  26 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION\r
  27 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.\r
  28 //\r
  29 \r
  30 #if NET_2_0\r
  31 \r
  32 using System;\r
  33 using System.Web.Security;\r
  34 using System.Data;\r
  35 using System.Data.OleDb;\r
  36 using System.Data.Common;\r
  37 using System.Collections.Generic;\r
  38 using System.Text;\r
  39 \r
  40 namespace Mainsoft.Web.Security\r
  41 {\r
  42         static class DerbyRolesHelper\r
  43         {\r
  44                 private static OleDbParameter AddParameter (OleDbCommand command, string paramName, object paramValue)\r
  45                 {\r
  46                         OleDbParameter prm = new OleDbParameter (paramName, paramValue);\r
  47                         command.Parameters.Add (prm);\r
  48                         return prm;\r
  49                 }\r
  50 \r
  51                 public static int Roles_CreateRole (DbConnection connection, string applicationName, string rolename)\r
  52                 {\r
  53                         string appId = (string) DerbyApplicationsHelper.Applications_CreateApplication (connection, applicationName);\r
  54                         if (appId == null)\r
  55                                 return 1;\r
  56 \r
  57                         string querySelect = "SELECT RoleName FROM aspnet_Roles WHERE ApplicationId = ? AND LoweredRoleName = ?";\r
  58                         OleDbCommand cmdSelect = new OleDbCommand (querySelect, (OleDbConnection) connection);\r
  59                         AddParameter (cmdSelect, "ApplicationId", appId);\r
  60                         AddParameter (cmdSelect, "LoweredRoleName", rolename.ToLowerInvariant ());\r
  61 \r
  62                         using (OleDbDataReader reader = cmdSelect.ExecuteReader ()) {\r
  63                                 if (reader.Read ())\r
  64                                         return 2; // role already exists\r
  65                         }\r
  66 \r
  67                         string queryInsert = "INSERT INTO aspnet_Roles (ApplicationId, RoleId, RoleName, LoweredRoleName) VALUES (?, ?, ?, ?)";\r
  68                         OleDbCommand cmdInsert = new OleDbCommand (queryInsert, (OleDbConnection) connection);\r
  69                         AddParameter (cmdInsert, "ApplicationId", appId);\r
  70                         AddParameter (cmdInsert, "RoleId", Guid.NewGuid ().ToString ());\r
  71                         AddParameter (cmdInsert, "RoleName", rolename);\r
  72                         AddParameter (cmdInsert, "LoweredRoleName", rolename.ToLowerInvariant ());\r
  73                         cmdInsert.ExecuteNonQuery ();\r
  74 \r
  75                         return 0;\r
  76                 }\r
  77 \r
  78                 public static int Roles_DeleteRole (DbConnection connection, string applicationName, string rolename, bool deleteOnlyIfRoleIsEmpty)\r
  79                 {\r
  80                         string appId = DerbyApplicationsHelper.GetApplicationId (connection, applicationName);\r
  81                         if (appId == null)\r
  82                                 return 1;\r
  83 \r
  84                         string roleId = GetRoleId (connection, appId, rolename);\r
  85                         if (roleId == null)\r
  86                                 return 2;\r
  87 \r
  88                         if (deleteOnlyIfRoleIsEmpty) {\r
  89                                 string querySelect = "SELECT RoleId FROM aspnet_UsersInRoles WHERE RoleId = ?";\r
  90                                 OleDbCommand cmdSelect = new OleDbCommand (querySelect, (OleDbConnection) connection);\r
  91                                 AddParameter (cmdSelect, "RoleId", roleId);\r
  92                                 using (OleDbDataReader reader = cmdSelect.ExecuteReader ()) {\r
  93                                         if (reader.Read ())\r
  94                                                 // role is not empty\r
  95                                                 return 3;\r
  96                                 }\r
  97                         }\r
  98 \r
  99                         string queryDelUsers = "DELETE FROM aspnet_UsersInRoles WHERE RoleId = ?";\r
 100                         OleDbCommand cmdDelUsers = new OleDbCommand (queryDelUsers, (OleDbConnection) connection);\r
 101                         AddParameter (cmdDelUsers, "RoleId", roleId);\r
 102                         cmdDelUsers.ExecuteNonQuery ();\r
 103 \r
 104                         string queryDelRole = "DELETE FROM aspnet_Roles WHERE ApplicationId = ? AND RoleId = ? ";\r
 105                         OleDbCommand cmdDelRole = new OleDbCommand (queryDelRole, (OleDbConnection) connection);\r
 106                         AddParameter (cmdDelRole, "ApplicationId", appId);\r
 107                         AddParameter (cmdDelRole, "RoleId", roleId);\r
 108                         cmdDelRole.ExecuteNonQuery ();\r
 109 \r
 110                         return 0;\r
 111                 }\r
 112 \r
 113                 public static int Roles_GetAllRoles (DbConnection connection, string applicationName, out DbDataReader reader)\r
 114                 {\r
 115                         reader = null;\r
 116                         string appId = DerbyApplicationsHelper.GetApplicationId (connection, applicationName);\r
 117                         if (appId == null)\r
 118                                 return 1;\r
 119 \r
 120                         string querySelect = "SELECT RoleName FROM aspnet_Roles WHERE ApplicationId = ? ORDER BY RoleName";\r
 121                         OleDbCommand cmdSelect = new OleDbCommand (querySelect, (OleDbConnection) connection);\r
 122                         AddParameter (cmdSelect, "ApplicationId", appId);\r
 123                         reader = cmdSelect.ExecuteReader ();\r
 124 \r
 125                         return 0;\r
 126                 }\r
 127 \r
 128                 public static int Roles_RoleExists (DbConnection connection, string applicationName, string rolename)\r
 129                 {\r
 130                         string appId = DerbyApplicationsHelper.GetApplicationId (connection, applicationName);\r
 131                         if (appId == null)\r
 132                                 return 1;\r
 133 \r
 134                         string querySelect = "SELECT RoleName FROM aspnet_Roles WHERE ApplicationId = ? AND LoweredRoleName = ?";\r
 135                         OleDbCommand cmdSelect = new OleDbCommand (querySelect, (OleDbConnection) connection);\r
 136                         AddParameter (cmdSelect, "ApplicationId", appId);\r
 137                         AddParameter (cmdSelect, "LoweredRoleName", rolename.ToLowerInvariant ());\r
 138 \r
 139                         using (OleDbDataReader reader = cmdSelect.ExecuteReader ()) {\r
 140                                 if (reader.Read ())\r
 141                                         return 2;\r
 142                         }\r
 143                         return 0;\r
 144                 }\r
 145 \r
 146                 public static int UsersInRoles_AddUsersToRoles (DbConnection connection, string applicationName, string [] userNames, string [] roleNames, DateTime currentTimeUtc)\r
 147                 {\r
 148                         string appId = DerbyApplicationsHelper.GetApplicationId (connection, applicationName);\r
 149                         if (appId == null)\r
 150                                 return 1;\r
 151 \r
 152                         string [] userIds = new string [userNames.Length];\r
 153                         string [] loweredUsernames = new string [userNames.Length];\r
 154                         string [] roleIds = new string [roleNames.Length];\r
 155 \r
 156                         string querySelUsers = "SELECT UserId, LoweredUserName FROM aspnet_Users WHERE ApplicationId = ? AND LoweredUserName in " + GetPrms (userNames.Length);\r
 157                         OleDbCommand cmdSelUsers = new OleDbCommand (querySelUsers, (OleDbConnection) connection);\r
 158                         AddParameter (cmdSelUsers, "ApplicationId", appId);\r
 159                         for (int i = 0; i < userNames.Length; i++)\r
 160                                 AddParameter (cmdSelUsers, "LoweredUserName", userNames [i].ToLowerInvariant ());\r
 161 \r
 162                         int userIndex = 0;\r
 163                         using (OleDbDataReader reader = cmdSelUsers.ExecuteReader ()) {\r
 164                                 while (reader.Read ()) {\r
 165                                         userIds [userIndex] = reader.GetString (0);\r
 166                                         loweredUsernames [userIndex] = reader.GetString (1);\r
 167                                         userIndex++;\r
 168                                 }\r
 169                         }\r
 170 \r
 171                         if (userNames.Length != userIndex) {\r
 172                                 // find not existing users and create them\r
 173                                 for (int j = 0; j < userNames.Length; j++)\r
 174                                         if (Array.IndexOf (loweredUsernames, userNames [j].ToLowerInvariant ()) < 0) {\r
 175                                                 string newUserId = Guid.NewGuid ().ToString ();\r
 176                                                 string queryAddUser = "INSERT INTO aspnet_Users (ApplicationId, UserId, UserName, " +\r
 177                                                         "LoweredUserName, IsAnonymous, LastActivityDate) VALUES (?, ?, ?, ?, ?, ?)";\r
 178                                                 OleDbCommand cmdAddUser = new OleDbCommand (queryAddUser, (OleDbConnection) connection);\r
 179                                                 AddParameter (cmdAddUser, "ApplicationId", appId);\r
 180                                                 AddParameter (cmdAddUser, "UserId", newUserId);\r
 181                                                 AddParameter (cmdAddUser, "UserName", userNames [j]);\r
 182                                                 AddParameter (cmdAddUser, "LoweredUserName", userNames [j].ToLowerInvariant ());\r
 183                                                 AddParameter (cmdAddUser, "IsAnonymous", 0);\r
 184                                                 AddParameter (cmdAddUser, "LastActivityDate", DateTime.UtcNow);\r
 185                                                 cmdAddUser.ExecuteNonQuery ();\r
 186 \r
 187                                                 userIds [userIndex++] = newUserId;\r
 188                                         }\r
 189                         }\r
 190 \r
 191 \r
 192                         string querySelRoles = "SELECT RoleId FROM aspnet_Roles WHERE ApplicationId = ? AND LoweredRoleName in " + GetPrms (roleNames.Length);\r
 193                         OleDbCommand cmdSelRoles = new OleDbCommand (querySelRoles, (OleDbConnection) connection);\r
 194                         AddParameter (cmdSelRoles, "ApplicationId", appId);\r
 195                         for (int i = 0; i < roleNames.Length; i++)\r
 196                                 AddParameter (cmdSelRoles, "LoweredRoleName", roleNames [i].ToLowerInvariant ());\r
 197 \r
 198                         using (OleDbDataReader reader = cmdSelRoles.ExecuteReader ()) {\r
 199                                 int i = 0;\r
 200                                 while (reader.Read ())\r
 201                                         roleIds [i++] = reader.GetString (0);\r
 202 \r
 203                                 if (roleNames.Length != i)\r
 204                                         return 2; // one or more roles not found\r
 205                         }\r
 206 \r
 207                         string querySelCount = "SELECT COUNT(*) FROM aspnet_UsersInRoles WHERE UserId in " + GetPrms (userNames.Length) + " AND RoleId in " + GetPrms (roleNames.Length);\r
 208                         OleDbCommand cmdSelCount = new OleDbCommand (querySelCount, (OleDbConnection) connection);\r
 209                         foreach (string userId in userIds)\r
 210                                 AddParameter (cmdSelCount, "UserId", userId);\r
 211                         foreach (string roleId in roleIds)\r
 212                                 AddParameter (cmdSelCount, "RoleId", roleId);\r
 213                         using (OleDbDataReader reader = cmdSelCount.ExecuteReader ()) {\r
 214                                 if (reader.Read ())\r
 215                                         if (reader.GetInt32 (0) > 0)\r
 216                                                 return 3;\r
 217                         }\r
 218 \r
 219                         string valuesExp = string.Empty;\r
 220                         int pairs = userNames.Length * roleNames.Length;\r
 221                         for (int i = 0; i < pairs; i++)\r
 222                                 valuesExp += "(?, ?),";\r
 223 \r
 224                         string queryInsert = "INSERT INTO aspnet_UsersInRoles (UserId, RoleId) VALUES " + valuesExp.Trim (',');\r
 225                         OleDbCommand cmdInsert = new OleDbCommand (queryInsert, (OleDbConnection) connection);\r
 226                         foreach (string roleId in roleIds)\r
 227                                 foreach (string userId in userIds) {\r
 228                                         AddParameter (cmdInsert, "UserId", userId);\r
 229                                         AddParameter (cmdInsert, "RoleId", roleId);\r
 230                                 }\r
 231 \r
 232                         cmdInsert.ExecuteNonQuery ();\r
 233                         return 0;\r
 234                 }\r
 235 \r
 236                 public static int UsersInRoles_FindUsersInRole (DbConnection connection, string applicationName, string rolename, string userNameToMatch, out DbDataReader reader)\r
 237                 {\r
 238                         reader = null;\r
 239                         string appId = DerbyApplicationsHelper.GetApplicationId (connection, applicationName);\r
 240                         if (appId == null)\r
 241                                 return 1;\r
 242 \r
 243                         string roleId = GetRoleId (connection, appId, rolename);\r
 244                         if (roleId == null)\r
 245                                 return 2;\r
 246 \r
 247                         string querySelect = "SELECT usr.UserName FROM aspnet_Users usr, aspnet_UsersInRoles uir " +
 248                                 "WHERE usr.UserId = uir.UserId AND usr.ApplicationId = ? AND uir.RoleId = ? AND LoweredUserName LIKE ? " +
 249                                 "ORDER BY usr.UserName";\r
 250                         OleDbCommand cmdSelect = new OleDbCommand (querySelect, (OleDbConnection) connection);\r
 251                         AddParameter (cmdSelect, "ApplicationId", appId);\r
 252                         AddParameter (cmdSelect, "RoleId", roleId);\r
 253                         AddParameter (cmdSelect, "LoweredUserName", "%" + userNameToMatch.ToLowerInvariant() + "%");\r
 254                         reader = cmdSelect.ExecuteReader ();\r
 255 \r
 256                         return 0;\r
 257                 }\r
 258 \r
 259                 public static int UsersInRoles_GetRolesForUser (DbConnection connection, string applicationName, string username, out DbDataReader reader)\r
 260                 {\r
 261                         reader = null;\r
 262                         string appId = DerbyApplicationsHelper.GetApplicationId (connection, applicationName);\r
 263                         if (appId == null)\r
 264                                 return 1;\r
 265 \r
 266                         string userId = GetUserId (connection, appId, username);\r
 267                         if (userId == null)\r
 268                                 return 2;\r
 269 \r
 270                         string querySelect = "SELECT rol.RoleName FROM aspnet_Roles rol, aspnet_UsersInRoles uir " +\r
 271                                 "WHERE rol.RoleId = uir.RoleId AND rol.ApplicationId = ? AND uir.UserId = ? ORDER BY rol.RoleName";\r
 272                         OleDbCommand cmdSelect = new OleDbCommand (querySelect, (OleDbConnection) connection);\r
 273                         AddParameter (cmdSelect, "ApplicationId", appId);\r
 274                         AddParameter (cmdSelect, "UserId", userId);\r
 275                         reader = cmdSelect.ExecuteReader ();\r
 276 \r
 277                         return 0;\r
 278                 }\r
 279 \r
 280                 public static int UsersInRoles_GetUsersInRoles (DbConnection connection, string applicationName, string rolename, out DbDataReader reader)\r
 281                 {\r
 282                         reader = null;\r
 283                         string appId = DerbyApplicationsHelper.GetApplicationId (connection, applicationName);\r
 284                         if (appId == null)\r
 285                                 return 1;\r
 286 \r
 287                         string roleId = GetRoleId (connection, appId, rolename);\r
 288                         if (roleId == null)\r
 289                                 return 2;\r
 290 \r
 291                         string querySelect = "SELECT usr.UserName FROM aspnet_Users usr, aspnet_UsersInRoles uir " +\r
 292                                 "WHERE usr.UserId = uir.UserId AND usr.ApplicationId = ? AND uir.RoleId = ? ORDER BY usr.UserName";\r
 293                         OleDbCommand cmdSelect = new OleDbCommand (querySelect, (OleDbConnection) connection);\r
 294                         AddParameter (cmdSelect, "ApplicationId", appId);\r
 295                         AddParameter (cmdSelect, "RoleId", roleId);\r
 296                         reader = cmdSelect.ExecuteReader ();\r
 297 \r
 298                         return 0;\r
 299                 }\r
 300 \r
 301                 public static int UsersInRoles_IsUserInRole (DbConnection connection, string applicationName, string username, string rolename)\r
 302                 {\r
 303                         string appId = DerbyApplicationsHelper.GetApplicationId (connection, applicationName);\r
 304                         if (appId == null)\r
 305                                 return 1;\r
 306 \r
 307                         string userId = GetUserId (connection, appId, username);\r
 308                         if (userId == null)\r
 309                                 return 2;\r
 310 \r
 311                         string roleId = GetRoleId (connection, appId, rolename);\r
 312                         if (roleId == null)\r
 313                                 return 3;\r
 314 \r
 315                         string querySelect = "SELECT UserId FROM aspnet_UsersInRoles WHERE UserId = ? AND RoleId = ?";\r
 316                         OleDbCommand cmdSelect = new OleDbCommand (querySelect, (OleDbConnection) connection);\r
 317                         AddParameter (cmdSelect, "UserId", userId);\r
 318                         AddParameter (cmdSelect, "RoleId", roleId);\r
 319                         using (OleDbDataReader reader = cmdSelect.ExecuteReader ()) {\r
 320                                 if (reader.Read ())\r
 321                                         return 4;\r
 322                         }\r
 323                         return 0;\r
 324                 }\r
 325 \r
 326                 public static int UsersInRoles_RemoveUsersFromRoles (DbConnection connection, string applicationName, string [] userNames, string [] roleNames)\r
 327                 {\r
 328                         string appId = DerbyApplicationsHelper.GetApplicationId (connection, applicationName);\r
 329                         if (appId == null)\r
 330                                 return 1;\r
 331 \r
 332                         string [] userIds = new string [userNames.Length];\r
 333                         string [] roleIds = new string [roleNames.Length];\r
 334 \r
 335                         string querySelUsers = "SELECT UserId FROM aspnet_Users WHERE ApplicationId = ? AND LoweredUserName in " + GetPrms (userNames.Length);\r
 336                         OleDbCommand cmdSelUsers = new OleDbCommand (querySelUsers, (OleDbConnection) connection);\r
 337                         AddParameter (cmdSelUsers, "ApplicationId", appId);\r
 338                         for (int i = 0; i < userNames.Length; i++)\r
 339                                 AddParameter (cmdSelUsers, "LoweredUserName", userNames [i].ToLowerInvariant ());\r
 340 \r
 341                         using (OleDbDataReader reader = cmdSelUsers.ExecuteReader ()) {\r
 342                                 int i = 0;\r
 343                                 while (reader.Read ())\r
 344                                         userIds [i++] = reader.GetString (0);\r
 345 \r
 346                                 if (userNames.Length != i)\r
 347                                         return 2; // one or more users not found\r
 348                         }\r
 349 \r
 350                         string querySelRoles = "SELECT RoleId FROM aspnet_Roles WHERE ApplicationId = ? AND LoweredRoleName in " + GetPrms (roleNames.Length);\r
 351                         OleDbCommand cmdSelRoles = new OleDbCommand (querySelRoles, (OleDbConnection) connection);\r
 352                         AddParameter (cmdSelRoles, "ApplicationId", appId);\r
 353                         for (int i = 0; i < roleNames.Length; i++)\r
 354                                 AddParameter (cmdSelRoles, "LoweredRoleName", roleNames [i].ToLowerInvariant ());\r
 355 \r
 356                         using (OleDbDataReader reader = cmdSelRoles.ExecuteReader ()) {\r
 357                                 int i = 0;\r
 358                                 while (reader.Read ())\r
 359                                         roleIds [i++] = reader.GetString (0);\r
 360 \r
 361                                 if (roleNames.Length != i)\r
 362                                         return 3; // one or more roles not found\r
 363                         }\r
 364 \r
 365                         string querySelCount = "SELECT COUNT(*) FROM aspnet_UsersInRoles WHERE UserId in " + GetPrms (userNames.Length) + " AND RoleId in " + GetPrms (roleNames.Length);\r
 366                         OleDbCommand cmdSelCount = new OleDbCommand (querySelCount, (OleDbConnection) connection);\r
 367                         foreach (string userId in userIds)\r
 368                                 AddParameter (cmdSelCount, "UserId", userId);\r
 369                         foreach (string roleId in roleIds)\r
 370                                 AddParameter (cmdSelCount, "RoleId", roleId);\r
 371                         using (OleDbDataReader reader = cmdSelCount.ExecuteReader ()) {\r
 372                                 if (reader.Read ())\r
 373                                         if (userNames.Length * roleNames.Length > reader.GetInt32 (0))\r
 374                                                 return 4;\r
 375                         }\r
 376 \r
 377                         string queryDelete = "DELETE FROM aspnet_UsersInRoles WHERE UserId in " + GetPrms (userNames.Length) + " AND RoleId in " + GetPrms (roleNames.Length);\r
 378                         OleDbCommand cmdDelete = new OleDbCommand (queryDelete, (OleDbConnection) connection);\r
 379                         foreach (string userId in userIds)\r
 380                                 AddParameter (cmdDelete, "UserId", userId);\r
 381                         foreach (string roleId in roleIds)\r
 382                                 AddParameter (cmdDelete, "RoleId", roleId);\r
 383                         cmdDelete.ExecuteNonQuery ();\r
 384 \r
 385                         return 0;\r
 386                 }\r
 387 \r
 388                 private static string GetRoleId (DbConnection connection, string applicationId, string rolename)\r
 389                 {\r
 390                         string selectQuery = "SELECT RoleId FROM aspnet_Roles WHERE LoweredRoleName = ? AND ApplicationId = ?";\r
 391 \r
 392                         OleDbCommand selectCmd = new OleDbCommand (selectQuery, (OleDbConnection) connection);\r
 393                         AddParameter (selectCmd, "LoweredRoleName", rolename.ToLowerInvariant ());\r
 394                         AddParameter (selectCmd, "ApplicationId", applicationId);\r
 395                         using (OleDbDataReader reader = selectCmd.ExecuteReader ()) {\r
 396                                 if (reader.Read ())\r
 397                                         return reader.GetString (0);\r
 398                         }\r
 399 \r
 400                         return null;\r
 401                 }\r
 402 \r
 403                 private static string GetUserId (DbConnection connection, string applicationId, string username)\r
 404                 {\r
 405                         string selectQuery = "SELECT UserId FROM aspnet_Users WHERE LoweredUserName = ? AND ApplicationId = ?";\r
 406 \r
 407                         OleDbCommand selectCmd = new OleDbCommand (selectQuery, (OleDbConnection) connection);\r
 408                         AddParameter (selectCmd, "LoweredUserName", username.ToLowerInvariant ());\r
 409                         AddParameter (selectCmd, "ApplicationId", applicationId);\r
 410                         using (OleDbDataReader reader = selectCmd.ExecuteReader ()) {\r
 411                                 if (reader.Read ())\r
 412                                         return reader.GetString (0);\r
 413                         }\r
 414 \r
 415                         return null;\r
 416                 }\r
 417 \r
 418                 private static string GetPrms (int n)\r
 419                 {\r
 420                         string exp = string.Empty;\r
 421                         for (int i = 0; i < n; i++)\r
 422                                 exp += "?,";\r
 423 \r
 424                         exp = "(" + exp.Trim (',') + ")";\r
 425                         return exp;\r
 426                 }\r
 427         }\r
 428 }\r
 429 \r
 430 #endif