Mono.Data.Sqlite.SqliteConnection.Schema_IndexColumns C# (CSharp) Method

    private DataTable Schema_IndexColumns(string strCatalog, string strTable, string strIndex, string strColumn)
    {
      DataTable tbl = new DataTable("IndexColumns");
      DataRow row;
      List<KeyValuePair<int, string>> primaryKeys = new List<KeyValuePair<int, string>>();
      bool maybeRowId;

      tbl.Locale = CultureInfo.InvariantCulture;
      tbl.Columns.Add("CONSTRAINT_CATALOG", typeof(string));
      tbl.Columns.Add("CONSTRAINT_SCHEMA", typeof(string));
      tbl.Columns.Add("CONSTRAINT_NAME", typeof(string));
      tbl.Columns.Add("TABLE_CATALOG", typeof(string));
      tbl.Columns.Add("TABLE_SCHEMA", typeof(string));
      tbl.Columns.Add("TABLE_NAME", typeof(string));
      tbl.Columns.Add("COLUMN_NAME", typeof(string));
      tbl.Columns.Add("ORDINAL_POSITION", typeof(int));
      tbl.Columns.Add("INDEX_NAME", typeof(string));
      tbl.Columns.Add("COLLATION_NAME", typeof(string));
      tbl.Columns.Add("SORT_MODE", typeof(string));
      tbl.Columns.Add("CONFLICT_OPTION", typeof(int));

      if (String.IsNullOrEmpty(strCatalog)) strCatalog = "main";

      string master = (String.Compare(strCatalog, "temp", true, CultureInfo.InvariantCulture) == 0) ? _tempmasterdb : _masterdb;

      tbl.BeginLoadData();

      using (SqliteCommand cmdTables = new SqliteCommand(String.Format(CultureInfo.InvariantCulture, "SELECT * FROM [{0}].[{1}] WHERE [type] LIKE 'table'", strCatalog, master), this))
      using (SqliteDataReader rdTables = cmdTables.ExecuteReader())
      {
        while (rdTables.Read())
        {
          maybeRowId = false;
          primaryKeys.Clear();
          if (String.IsNullOrEmpty(strTable) || String.Compare(rdTables.GetString(2), strTable, true, CultureInfo.InvariantCulture) == 0)
          {
            try
            {
              using (SqliteCommand cmdTable = new SqliteCommand(String.Format(CultureInfo.InvariantCulture, "PRAGMA [{0}].table_info([{1}])", strCatalog, rdTables.GetString(2)), this))
              using (SqliteDataReader rdTable = cmdTable.ExecuteReader())
              {
                while (rdTable.Read())
                {
                  if (rdTable.GetInt32(5) == 1) // is a primary key
                  {
                    primaryKeys.Add(new KeyValuePair<int, string>(rdTable.GetInt32(0), rdTable.GetString(1)));
                    // Is an integer -- could be a rowid if no other primary keys exist in the table
                    if (String.Compare(rdTable.GetString(2), "INTEGER", true, CultureInfo.InvariantCulture) == 0)
                      maybeRowId = true;
                  }
                }
              }
            }
            catch (SqliteException)
            {
            }
            // This is a rowid row
            if (primaryKeys.Count == 1 && maybeRowId == true)
            {
              row = tbl.NewRow();
              row["CONSTRAINT_CATALOG"] = strCatalog;
              row["CONSTRAINT_NAME"] = String.Format(CultureInfo.InvariantCulture, "{1}_PK_{0}", rdTables.GetString(2), master);
              row["TABLE_CATALOG"] = strCatalog;
              row["TABLE_NAME"] = rdTables.GetString(2);
              row["COLUMN_NAME"] = primaryKeys[0].Value;
              row["INDEX_NAME"] = row["CONSTRAINT_NAME"];
              row["ORDINAL_POSITION"] = 0; // primaryKeys[0].Key;
              row["COLLATION_NAME"] = "BINARY";
              row["SORT_MODE"] = "ASC";
              row["CONFLICT_OPTION"] = 2;

              if (String.IsNullOrEmpty(strIndex) || String.Compare(strIndex, (string)row["INDEX_NAME"], true, CultureInfo.InvariantCulture) == 0)
                tbl.Rows.Add(row);
            }

            using (SqliteCommand cmdIndexes = new SqliteCommand(String.Format(CultureInfo.InvariantCulture, "SELECT * FROM [{0}].[{2}] WHERE [type] LIKE 'index' AND [tbl_name] LIKE '{1}'", strCatalog, rdTables.GetString(2).Replace("'", "''"), master), this))
            using (SqliteDataReader rdIndexes = cmdIndexes.ExecuteReader())
            {
              while (rdIndexes.Read())
              {
                int ordinal = 0;
                if (String.IsNullOrEmpty(strIndex) || String.Compare(strIndex, rdIndexes.GetString(1), true, CultureInfo.InvariantCulture) == 0)
                {
                  try
                  {
                    using (SqliteCommand cmdIndex = new SqliteCommand(String.Format(CultureInfo.InvariantCulture, "PRAGMA [{0}].index_info([{1}])", strCatalog, rdIndexes.GetString(1)), this))
                    using (SqliteDataReader rdIndex = cmdIndex.ExecuteReader())
                    {
                      while (rdIndex.Read())
                      {
                        row = tbl.NewRow();
                        row["CONSTRAINT_CATALOG"] = strCatalog;
                        row["CONSTRAINT_NAME"] = rdIndexes.GetString(1);
                        row["TABLE_CATALOG"] = strCatalog;
                        row["TABLE_NAME"] = rdIndexes.GetString(2);
                        row["COLUMN_NAME"] = rdIndex.GetString(2);
                        row["INDEX_NAME"] = rdIndexes.GetString(1);
                        row["ORDINAL_POSITION"] = ordinal; // rdIndex.GetInt32(1);

                        string collationSequence;
                        int sortMode;
                        int onError;
                        _sql.GetIndexColumnExtendedInfo(strCatalog, rdIndexes.GetString(1), rdIndex.GetString(2), out sortMode, out onError, out collationSequence);

                        if (String.IsNullOrEmpty(collationSequence) == false)
                          row["COLLATION_NAME"] = collationSequence;

                        row["SORT_MODE"] = (sortMode == 0) ? "ASC" : "DESC";
                        row["CONFLICT_OPTION"] = onError;

                        ordinal++;

                        if (String.IsNullOrEmpty(strColumn) || String.Compare(strColumn, row["COLUMN_NAME"].ToString(), true, CultureInfo.InvariantCulture) == 0)
                          tbl.Rows.Add(row);
                      }
                    }
                  }
                  catch (SqliteException)
                  {
                  }
                }
              }
            }
          }
        }
      }

      tbl.EndLoadData();
      tbl.AcceptChanges();

      return tbl;
    }