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

    private DataTable Schema_ForeignKeys(string strCatalog, string strTable, string strKeyName)
    {
      DataTable tbl = new DataTable("ForeignKeys");
      DataRow row;

      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("CONSTRAINT_TYPE", typeof(string));
      tbl.Columns.Add("IS_DEFERRABLE", typeof(bool));
      tbl.Columns.Add("INITIALLY_DEFERRED", typeof(bool));
      tbl.Columns.Add("FKEY_FROM_COLUMN", typeof(string));
      tbl.Columns.Add("FKEY_FROM_ORDINAL_POSITION", typeof(int));
      tbl.Columns.Add("FKEY_TO_CATALOG", typeof(string));
      tbl.Columns.Add("FKEY_TO_SCHEMA", typeof(string));
      tbl.Columns.Add("FKEY_TO_TABLE", typeof(string));
      tbl.Columns.Add("FKEY_TO_COLUMN", typeof(string));

      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())
        {
          if (String.IsNullOrEmpty(strTable) || String.Compare(strTable, rdTables.GetString(2), true, CultureInfo.InvariantCulture) == 0)
          {
            try
            {
              using (SqliteCommandBuilder builder = new SqliteCommandBuilder())
              //using (SqliteCommand cmdTable = new SqliteCommand(String.Format(CultureInfo.InvariantCulture, "SELECT * FROM [{0}].[{1}]", strCatalog, rdTables.GetString(2)), this))
              //using (SqliteDataReader rdTable = cmdTable.ExecuteReader(CommandBehavior.SchemaOnly))
              using (SqliteCommand cmdKey = new SqliteCommand(String.Format(CultureInfo.InvariantCulture, "PRAGMA [{0}].foreign_key_list([{1}])", strCatalog, rdTables.GetString(2)), this))
              using (SqliteDataReader rdKey = cmdKey.ExecuteReader())
              {
                while (rdKey.Read())
                {
                  row = tbl.NewRow();
                  row["CONSTRAINT_CATALOG"] = strCatalog;
                  row["CONSTRAINT_NAME"] = String.Format(CultureInfo.InvariantCulture, "FK_{0}_{1}", rdTables[2], rdKey.GetInt32(0));
                  row["TABLE_CATALOG"] = strCatalog;
                  row["TABLE_NAME"] = builder.UnquoteIdentifier(rdTables.GetString(2));
                  row["CONSTRAINT_TYPE"] = "FOREIGN KEY";
                  row["IS_DEFERRABLE"] = false;
                  row["INITIALLY_DEFERRED"] = false;
                  row["FKEY_FROM_COLUMN"] = builder.UnquoteIdentifier(rdKey[3].ToString());
                  row["FKEY_TO_CATALOG"] = strCatalog;
                  row["FKEY_TO_TABLE"] = builder.UnquoteIdentifier(rdKey[2].ToString());
                  row["FKEY_TO_COLUMN"] = builder.UnquoteIdentifier(rdKey[4].ToString());
                  row["FKEY_FROM_ORDINAL_POSITION"] = rdKey[1];

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

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

      return tbl;
    }