protected virtual MyCatSchemaCollection GetCollections()
        {
            object[][] collections = new object[][]
            {
                new object[] { "MetaDataCollections", 0, 0 },
                new object[] { "DataSourceInformation", 0, 0 },
                new object[] { "DataTypes", 0, 0 },
                new object[] { "Restrictions", 0, 0 },
                new object[] { "ReservedWords", 0, 0 },
                new object[] { "Databases", 1, 1 },
                new object[] { "Tables", 4, 2 },
                new object[] { "Columns", 4, 4 },
                new object[] { "Users", 1, 1 },
                new object[] { "Foreign Keys", 4, 3 },
                new object[] { "IndexColumns", 5, 4 },
                new object[] { "Indexes", 4, 3 },
                new object[] { "Foreign Key Columns", 4, 3 },
                new object[] { "UDF", 1, 1 }
            };

            MyCatSchemaCollection dt = new MyCatSchemaCollection("MetaDataCollections");

            dt.AddColumn("CollectionName", typeof(string));
            dt.AddColumn("NumberOfRestrictions", typeof(int));
            dt.AddColumn("NumberOfIdentifierParts", typeof(int));

            FillTable(dt, collections);

            return(dt);
        }
        public virtual MyCatSchemaCollection GetIndexes(string[] restrictions)
        {
            MyCatSchemaCollection dt = new MyCatSchemaCollection("Indexes");

            dt.AddColumn("INDEX_CATALOG", typeof(string));
            dt.AddColumn("INDEX_SCHEMA", typeof(string));
            dt.AddColumn("INDEX_NAME", typeof(string));
            dt.AddColumn("TABLE_NAME", typeof(string));
            dt.AddColumn("UNIQUE", typeof(bool));
            dt.AddColumn("PRIMARY", typeof(bool));
            dt.AddColumn("TYPE", typeof(string));
            dt.AddColumn("COMMENT", typeof(string));

            // Get the list of tables first
            int max = restrictions == null ? 4 : restrictions.Length;

            string[] tableRestrictions = new string[Math.Max(max, 4)];
            if (restrictions != null)
            {
                restrictions.CopyTo(tableRestrictions, 0);
            }
            tableRestrictions[3] = "BASE TABLE";
            MyCatSchemaCollection tables = GetTables(tableRestrictions);

            foreach (MyCatSchemaRow table in tables.Rows)
            {
                string sql = String.Format("SHOW INDEX FROM `{0}`.`{1}`",
                                           MyCatHelper.DoubleQuoteString((string)table["TABLE_SCHEMA"]),
                                           MyCatHelper.DoubleQuoteString((string)table["TABLE_NAME"]));
                MyCatSchemaCollection indexes = QueryCollection("indexes", sql);

                foreach (MyCatSchemaRow index in indexes.Rows)
                {
                    long seq_index = (long)index["SEQ_IN_INDEX"];
                    if (seq_index != 1)
                    {
                        continue;
                    }
                    if (restrictions != null && restrictions.Length == 4 &&
                        restrictions[3] != null &&
                        !index["KEY_NAME"].Equals(restrictions[3]))
                    {
                        continue;
                    }
                    MyCatSchemaRow row = dt.AddRow();
                    row["INDEX_CATALOG"] = null;
                    row["INDEX_SCHEMA"]  = table["TABLE_SCHEMA"];
                    row["INDEX_NAME"]    = index["KEY_NAME"];
                    row["TABLE_NAME"]    = index["TABLE"];
                    row["UNIQUE"]        = (long)index["NON_UNIQUE"] == 0;
                    row["PRIMARY"]       = index["KEY_NAME"].Equals("PRIMARY");
                    row["TYPE"]          = index["INDEX_TYPE"];
                    row["COMMENT"]       = index["COMMENT"];
                }
            }

            return(dt);
        }
        private MyCatSchemaCollection GetTable(string sql)
        {
            MyCatSchemaCollection c      = new MyCatSchemaCollection();
            MyCatCommand          cmd    = new MyCatCommand(sql, connection);
            MyCatDataReader       reader = cmd.ExecuteReader();

            // add columns
            for (int i = 0; i < reader.FieldCount; i++)
            {
                c.AddColumn(reader.GetName(i), reader.GetFieldType(i));
            }

            using (reader)
            {
                while (reader.Read())
                {
                    MyCatSchemaRow row = c.AddRow();
                    for (int i = 0; i < reader.FieldCount; i++)
                    {
                        row[i] = reader.GetValue(i);
                    }
                }
            }
            return(c);
        }
        protected virtual MyCatSchemaCollection GetRestrictions()
        {
            object[][] restrictions = new object[][]
            {
                new object[] { "Users", "Name", "", 0 },
                new object[] { "Databases", "Name", "", 0 },
                new object[] { "Tables", "Database", "", 0 },
                new object[] { "Tables", "Schema", "", 1 },
                new object[] { "Tables", "Table", "", 2 },
                new object[] { "Tables", "TableType", "", 3 },
                new object[] { "Columns", "Database", "", 0 },
                new object[] { "Columns", "Schema", "", 1 },
                new object[] { "Columns", "Table", "", 2 },
                new object[] { "Columns", "Column", "", 3 },
                new object[] { "Indexes", "Database", "", 0 },
                new object[] { "Indexes", "Schema", "", 1 },
                new object[] { "Indexes", "Table", "", 2 },
                new object[] { "Indexes", "Name", "", 3 },
                new object[] { "IndexColumns", "Database", "", 0 },
                new object[] { "IndexColumns", "Schema", "", 1 },
                new object[] { "IndexColumns", "Table", "", 2 },
                new object[] { "IndexColumns", "ConstraintName", "", 3 },
                new object[] { "IndexColumns", "Column", "", 4 },
                new object[] { "Foreign Keys", "Database", "", 0 },
                new object[] { "Foreign Keys", "Schema", "", 1 },
                new object[] { "Foreign Keys", "Table", "", 2 },
                new object[] { "Foreign Keys", "Constraint Name", "", 3 },
                new object[] { "Foreign Key Columns", "Catalog", "", 0 },
                new object[] { "Foreign Key Columns", "Schema", "", 1 },
                new object[] { "Foreign Key Columns", "Table", "", 2 },
                new object[] { "Foreign Key Columns", "Constraint Name", "", 3 },
                new object[] { "UDF", "Name", "", 0 }
            };

            MyCatSchemaCollection dt = new MyCatSchemaCollection("Restrictions");

            dt.AddColumn("CollectionName", typeof(string));
            dt.AddColumn("RestrictionName", typeof(string));
            dt.AddColumn("RestrictionDefault", typeof(string));
            dt.AddColumn("RestrictionNumber", typeof(int));

            FillTable(dt, restrictions);

            return(dt);
        }
        public virtual MyCatSchemaCollection GetUDF(string[] restrictions)
        {
            string sql = "SELECT name,ret,dl FROM mysql.func";

            if (restrictions != null)
            {
                if (restrictions.Length >= 1 && !String.IsNullOrEmpty(restrictions[0]))
                {
                    sql += String.Format(" WHERE name LIKE '{0}'", restrictions[0]);
                }
            }

            MyCatSchemaCollection dt = new MyCatSchemaCollection("User-defined Functions");

            dt.AddColumn("NAME", typeof(string));
            dt.AddColumn("RETURN_TYPE", typeof(int));
            dt.AddColumn("LIBRARY_NAME", typeof(string));

            MyCatCommand cmd = new MyCatCommand(sql, connection);

            try
            {
                using (MyCatDataReader reader = cmd.ExecuteReader())
                {
                    while (reader.Read())
                    {
                        MyCatSchemaRow row = dt.AddRow();
                        row[0] = reader.GetString(0);
                        row[1] = reader.GetInt32(1);
                        row[2] = reader.GetString(2);
                    }
                }
            }
            catch (MyCatException ex)
            {
                if (ex.Number != (int)MyCatErrorCode.TableAccessDenied)
                {
                    throw;
                }
                throw new MyCatException(Resources.UnableToEnumerateUDF, ex);
            }

            return(dt);
        }
        private MyCatSchemaCollection GetProceduresWithParameters(string[] restrictions)
        {
            MyCatSchemaCollection dt = GetProcedures(restrictions);

            dt.AddColumn("ParameterList", typeof(string));

            foreach (MyCatSchemaRow row in dt.Rows)
            {
                row["ParameterList"] = GetProcedureParameterLine(row);
            }
            return(dt);
        }
        public virtual MyCatSchemaCollection GetDatabases(string[] restrictions)
        {
            Regex regex       = null;
            int   caseSetting = Int32.Parse(connection.driver.Property("lower_case_table_names"));

            string sql = "SHOW DATABASES";

            // if lower_case_table_names is zero, then case lookup should be sensitive
            // so we can use LIKE to do the matching.
            if (caseSetting == 0)
            {
                if (restrictions != null && restrictions.Length >= 1)
                {
                    sql = sql + " LIKE '" + restrictions[0] + "'";
                }
            }

            MyCatSchemaCollection c = QueryCollection("Databases", sql);

            if (caseSetting != 0 && restrictions != null && restrictions.Length >= 1 && restrictions[0] != null)
            {
                regex = new Regex(restrictions[0], RegexOptions.IgnoreCase);
            }

            MyCatSchemaCollection c2 = new MyCatSchemaCollection("Databases");

            c2.AddColumn("CATALOG_NAME", typeof(string));
            c2.AddColumn("SCHEMA_NAME", typeof(string));

            foreach (MyCatSchemaRow row in c.Rows)
            {
                if (regex != null && !regex.Match(row[0].ToString()).Success)
                {
                    continue;
                }
                MyCatSchemaRow newRow = c2.AddRow();
                newRow[1] = row[0];
            }
            return(c2);
        }
        private static MyCatSchemaCollection GetReservedWords()
        {
            MyCatSchemaCollection dt = new MyCatSchemaCollection("ReservedWords");

#if !NETSTANDARD1_3
            dt.AddColumn(DbMetaDataColumnNames.ReservedWord, typeof(string));
            Stream str = Assembly.GetExecutingAssembly().GetManifestResourceStream(
                "Pomelo.Data.MyCat.Properties.ReservedWords.txt");
#else
            dt.AddColumn("ReservedWord", typeof(string));
            Stream str = typeof(SchemaProvider).GetTypeInfo().Assembly.GetManifestResourceStream("Pomelo.Data.MyCat.Properties.ReservedWords.txt");
#endif
            StreamReader sr   = new StreamReader(str);
            string       line = sr.ReadLine();
            while (line != null)
            {
                string[] keywords = line.Split(new char[] { ' ' });
                foreach (string s in keywords)
                {
                    if (String.IsNullOrEmpty(s))
                    {
                        continue;
                    }
                    MyCatSchemaRow row = dt.AddRow();
                    row[0] = s;
                }
                line = sr.ReadLine();
            }
#if NETSTANDARD1_3
            sr.Dispose();
            str.Dispose();
#else
            sr.Close();
            str.Close();
#endif


            return(dt);
        }
        public virtual MyCatSchemaCollection GetTables(string[] restrictions)
        {
            MyCatSchemaCollection c = new MyCatSchemaCollection("Tables");

            c.AddColumn("TABLE_CATALOG", typeof(string));
            c.AddColumn("TABLE_SCHEMA", typeof(string));
            c.AddColumn("TABLE_NAME", typeof(string));
            c.AddColumn("TABLE_TYPE", typeof(string));
            c.AddColumn("ENGINE", typeof(string));
            c.AddColumn("VERSION", typeof(ulong));
            c.AddColumn("ROW_FORMAT", typeof(string));
            c.AddColumn("TABLE_ROWS", typeof(ulong));
            c.AddColumn("AVG_ROW_LENGTH", typeof(ulong));
            c.AddColumn("DATA_LENGTH", typeof(ulong));
            c.AddColumn("MAX_DATA_LENGTH", typeof(ulong));
            c.AddColumn("INDEX_LENGTH", typeof(ulong));
            c.AddColumn("DATA_FREE", typeof(ulong));
            c.AddColumn("AUTO_INCREMENT", typeof(ulong));
            c.AddColumn("CREATE_TIME", typeof(DateTime));
            c.AddColumn("UPDATE_TIME", typeof(DateTime));
            c.AddColumn("CHECK_TIME", typeof(DateTime));
            c.AddColumn("TABLE_COLLATION", typeof(string));
            c.AddColumn("CHECKSUM", typeof(ulong));
            c.AddColumn("CREATE_OPTIONS", typeof(string));
            c.AddColumn("TABLE_COMMENT", typeof(string));

            // we have to new up a new restriction array here since
            // GetDatabases takes the database in the first slot
            string[] dbRestriction = new string[4];
            if (restrictions != null && restrictions.Length >= 2)
            {
                dbRestriction[0] = restrictions[1];
            }
            MyCatSchemaCollection databases = GetDatabases(dbRestriction);

            if (restrictions != null)
            {
                Array.Copy(restrictions, dbRestriction,
                           Math.Min(dbRestriction.Length, restrictions.Length));
            }

            foreach (MyCatSchemaRow row in databases.Rows)
            {
                dbRestriction[1] = row["SCHEMA_NAME"].ToString();
                FindTables(c, dbRestriction);
            }
            return(c);
        }
        private static MyCatSchemaCollection GetDataTypes()
        {
            MyCatSchemaCollection dt = new MyCatSchemaCollection("DataTypes");

            dt.AddColumn("TypeName", typeof(string));
            dt.AddColumn("ProviderDbType", typeof(int));
            dt.AddColumn("ColumnSize", typeof(long));
            dt.AddColumn("CreateFormat", typeof(string));
            dt.AddColumn("CreateParameters", typeof(string));
            dt.AddColumn("DataType", typeof(string));
            dt.AddColumn("IsAutoincrementable", typeof(bool));
            dt.AddColumn("IsBestMatch", typeof(bool));
            dt.AddColumn("IsCaseSensitive", typeof(bool));
            dt.AddColumn("IsFixedLength", typeof(bool));
            dt.AddColumn("IsFixedPrecisionScale", typeof(bool));
            dt.AddColumn("IsLong", typeof(bool));
            dt.AddColumn("IsNullable", typeof(bool));
            dt.AddColumn("IsSearchable", typeof(bool));
            dt.AddColumn("IsSearchableWithLike", typeof(bool));
            dt.AddColumn("IsUnsigned", typeof(bool));
            dt.AddColumn("MaximumScale", typeof(short));
            dt.AddColumn("MinimumScale", typeof(short));
            dt.AddColumn("IsConcurrencyType", typeof(bool));
            dt.AddColumn("IsLiteralSupported", typeof(bool));
            dt.AddColumn("LiteralPrefix", typeof(string));
            dt.AddColumn("LiteralSuffix", typeof(string));
            dt.AddColumn("NativeDataType", typeof(string));

            // have each one of the types contribute to the datatypes collection
            MyCatBit.SetDSInfo(dt);
            MyCatBinary.SetDSInfo(dt);
            MyCatDateTime.SetDSInfo(dt);
            MyCatTimeSpan.SetDSInfo(dt);
            MyCatString.SetDSInfo(dt);
            MyCatDouble.SetDSInfo(dt);
            MyCatSingle.SetDSInfo(dt);
            MyCatByte.SetDSInfo(dt);
            MyCatInt16.SetDSInfo(dt);
            MyCatInt32.SetDSInfo(dt);
            MyCatInt64.SetDSInfo(dt);
            MyCatDecimal.SetDSInfo(dt);
            MyCatUByte.SetDSInfo(dt);
            MyCatUInt16.SetDSInfo(dt);
            MyCatUInt32.SetDSInfo(dt);
            MyCatUInt64.SetDSInfo(dt);

            return(dt);
        }
        private MyCatSchemaCollection GetDataSourceInformation()
        {
#if NETSTANDARD1_3
            throw new NotSupportedException();
#else
            MyCatSchemaCollection dt = new MyCatSchemaCollection("DataSourceInformation");
            dt.AddColumn("CompositeIdentifierSeparatorPattern", typeof(string));
            dt.AddColumn("DataSourceProductName", typeof(string));
            dt.AddColumn("DataSourceProductVersion", typeof(string));
            dt.AddColumn("DataSourceProductVersionNormalized", typeof(string));
            dt.AddColumn("GroupByBehavior", typeof(GroupByBehavior));
            dt.AddColumn("IdentifierPattern", typeof(string));
            dt.AddColumn("IdentifierCase", typeof(IdentifierCase));
            dt.AddColumn("OrderByColumnsInSelect", typeof(bool));
            dt.AddColumn("ParameterMarkerFormat", typeof(string));
            dt.AddColumn("ParameterMarkerPattern", typeof(string));
            dt.AddColumn("ParameterNameMaxLength", typeof(int));
            dt.AddColumn("ParameterNamePattern", typeof(string));
            dt.AddColumn("QuotedIdentifierPattern", typeof(string));
            dt.AddColumn("QuotedIdentifierCase", typeof(IdentifierCase));
            dt.AddColumn("StatementSeparatorPattern", typeof(string));
            dt.AddColumn("StringLiteralPattern", typeof(string));
            dt.AddColumn("SupportedJoinOperators", typeof(SupportedJoinOperators));

            DBVersion v   = connection.driver.Version;
            string    ver = String.Format("{0:0}.{1:0}.{2:0}",
                                          v.Major, v.Minor, v.Build);

            MyCatSchemaRow row = dt.AddRow();
            row["CompositeIdentifierSeparatorPattern"] = "\\.";
            row["DataSourceProductName"]              = "MySQL";
            row["DataSourceProductVersion"]           = connection.ServerVersion;
            row["DataSourceProductVersionNormalized"] = ver;
            row["GroupByBehavior"]   = GroupByBehavior.Unrelated;
            row["IdentifierPattern"] =
                @"(^\`\p{Lo}\p{Lu}\p{Ll}_@#][\p{Lo}\p{Lu}\p{Ll}\p{Nd}@$#_]*$)|(^\`[^\`\0]|\`\`+\`$)|(^\"" + [^\""\0]|\""\""+\""$)";
            row["IdentifierCase"]         = IdentifierCase.Insensitive;
            row["OrderByColumnsInSelect"] = false;
            row["ParameterMarkerFormat"]  = "{0}";
            row["ParameterMarkerPattern"] = "(@[A-Za-z0-9_$#]*)";
            row["ParameterNameMaxLength"] = 128;
            row["ParameterNamePattern"]   =
                @"^[\p{Lo}\p{Lu}\p{Ll}\p{Lm}_@#][\p{Lo}\p{Lu}\p{Ll}\p{Lm}\p{Nd}\uff3f_@#\$]*(?=\s+|$)";
            row["QuotedIdentifierPattern"]   = @"(([^\`]|\`\`)*)";
            row["QuotedIdentifierCase"]      = IdentifierCase.Sensitive;
            row["StatementSeparatorPattern"] = ";";
            row["StringLiteralPattern"]      = "'(([^']|'')*)'";
            row["SupportedJoinOperators"]    = 15;
            dt.Rows.Add(row);

            return(dt);
#endif
        }
        public virtual MyCatSchemaCollection GetProcedures(string[] restrictions)
        {
            MyCatSchemaCollection dt = new MyCatSchemaCollection("Procedures");

            dt.AddColumn("SPECIFIC_NAME", typeof(string));
            dt.AddColumn("ROUTINE_CATALOG", typeof(string));
            dt.AddColumn("ROUTINE_SCHEMA", typeof(string));
            dt.AddColumn("ROUTINE_NAME", typeof(string));
            dt.AddColumn("ROUTINE_TYPE", typeof(string));
            dt.AddColumn("DTD_IDENTIFIER", typeof(string));
            dt.AddColumn("ROUTINE_BODY", typeof(string));
            dt.AddColumn("ROUTINE_DEFINITION", typeof(string));
            dt.AddColumn("EXTERNAL_NAME", typeof(string));
            dt.AddColumn("EXTERNAL_LANGUAGE", typeof(string));
            dt.AddColumn("PARAMETER_STYLE", typeof(string));
            dt.AddColumn("IS_DETERMINISTIC", typeof(string));
            dt.AddColumn("SQL_DATA_ACCESS", typeof(string));
            dt.AddColumn("SQL_PATH", typeof(string));
            dt.AddColumn("SECURITY_TYPE", typeof(string));
            dt.AddColumn("CREATED", typeof(DateTime));
            dt.AddColumn("LAST_ALTERED", typeof(DateTime));
            dt.AddColumn("SQL_MODE", typeof(string));
            dt.AddColumn("ROUTINE_COMMENT", typeof(string));
            dt.AddColumn("DEFINER", typeof(string));

            StringBuilder sql = new StringBuilder("SELECT * FROM mysql.proc WHERE 1=1");

            if (restrictions != null)
            {
                if (restrictions.Length >= 2 && restrictions[1] != null)
                {
                    sql.AppendFormat(CultureInfo.InvariantCulture,
                                     " AND db LIKE '{0}'", restrictions[1]);
                }
                if (restrictions.Length >= 3 && restrictions[2] != null)
                {
                    sql.AppendFormat(CultureInfo.InvariantCulture,
                                     " AND name LIKE '{0}'", restrictions[2]);
                }
                if (restrictions.Length >= 4 && restrictions[3] != null)
                {
                    sql.AppendFormat(CultureInfo.InvariantCulture,
                                     " AND type LIKE '{0}'", restrictions[3]);
                }
            }

            MyCatCommand cmd = new MyCatCommand(sql.ToString(), connection);

            using (MyCatDataReader reader = cmd.ExecuteReader())
            {
                while (reader.Read())
                {
                    MyCatSchemaRow row = dt.AddRow();
                    row["SPECIFIC_NAME"]   = reader.GetString("specific_name");
                    row["ROUTINE_CATALOG"] = DBNull.Value;
                    row["ROUTINE_SCHEMA"]  = reader.GetString("db");
                    row["ROUTINE_NAME"]    = reader.GetString("name");
                    string routineType = reader.GetString("type");
                    row["ROUTINE_TYPE"]   = routineType;
                    row["DTD_IDENTIFIER"] = StringUtility.ToLowerInvariant(routineType) == "function" ?
                                            (object)reader.GetString("returns") : DBNull.Value;
                    row["ROUTINE_BODY"]       = "SQL";
                    row["ROUTINE_DEFINITION"] = reader.GetString("body");
                    row["EXTERNAL_NAME"]      = DBNull.Value;
                    row["EXTERNAL_LANGUAGE"]  = DBNull.Value;
                    row["PARAMETER_STYLE"]    = "SQL";
                    row["IS_DETERMINISTIC"]   = reader.GetString("is_deterministic");
                    row["SQL_DATA_ACCESS"]    = reader.GetString("sql_data_access");
                    row["SQL_PATH"]           = DBNull.Value;
                    row["SECURITY_TYPE"]      = reader.GetString("security_type");
                    row["CREATED"]            = reader.GetDateTime("created");
                    row["LAST_ALTERED"]       = reader.GetDateTime("modified");
                    row["SQL_MODE"]           = reader.GetString("sql_mode");
                    row["ROUTINE_COMMENT"]    = reader.GetString("comment");
                    row["DEFINER"]            = reader.GetString("definer");
                }
            }

            return(dt);
        }
        public virtual MyCatSchemaCollection GetForeignKeyColumns(string[] restrictions)
        {
            MyCatSchemaCollection dt = new MyCatSchemaCollection("Foreign Keys");

            dt.AddColumn("CONSTRAINT_CATALOG", typeof(string));
            dt.AddColumn("CONSTRAINT_SCHEMA", typeof(string));
            dt.AddColumn("CONSTRAINT_NAME", typeof(string));
            dt.AddColumn("TABLE_CATALOG", typeof(string));
            dt.AddColumn("TABLE_SCHEMA", typeof(string));
            dt.AddColumn("TABLE_NAME", typeof(string));
            dt.AddColumn("COLUMN_NAME", typeof(string));
            dt.AddColumn("ORDINAL_POSITION", typeof(int));
            dt.AddColumn("REFERENCED_TABLE_CATALOG", typeof(string));
            dt.AddColumn("REFERENCED_TABLE_SCHEMA", typeof(string));
            dt.AddColumn("REFERENCED_TABLE_NAME", typeof(string));
            dt.AddColumn("REFERENCED_COLUMN_NAME", typeof(string));

            // first we use our restrictions to get a list of tables that should be
            // consulted.  We save the keyname restriction since GetTables doesn't
            // understand that.
            string keyName = null;

            if (restrictions != null && restrictions.Length >= 4)
            {
                keyName         = restrictions[3];
                restrictions[3] = null;
            }

            MyCatSchemaCollection tables = GetTables(restrictions);

            // now for each table retrieved, we call our helper function to
            // parse it's foreign keys
            foreach (MyCatSchemaRow table in tables.Rows)
            {
                GetForeignKeysOnTable(dt, table, keyName, true);
            }
            return(dt);
        }
        public virtual MyCatSchemaCollection GetIndexColumns(string[] restrictions)
        {
            MyCatSchemaCollection dt = new MyCatSchemaCollection("IndexColumns");

            dt.AddColumn("INDEX_CATALOG", typeof(string));
            dt.AddColumn("INDEX_SCHEMA", typeof(string));
            dt.AddColumn("INDEX_NAME", typeof(string));
            dt.AddColumn("TABLE_NAME", typeof(string));
            dt.AddColumn("COLUMN_NAME", typeof(string));
            dt.AddColumn("ORDINAL_POSITION", typeof(int));
            dt.AddColumn("SORT_ORDER", typeof(string));

            int max = restrictions == null ? 4 : restrictions.Length;

            string[] tableRestrictions = new string[Math.Max(max, 4)];
            if (restrictions != null)
            {
                restrictions.CopyTo(tableRestrictions, 0);
            }
            tableRestrictions[3] = "BASE TABLE";
            MyCatSchemaCollection tables = GetTables(tableRestrictions);

            foreach (MyCatSchemaRow table in tables.Rows)
            {
                string sql = String.Format("SHOW INDEX FROM `{0}`.`{1}`",
                                           table["TABLE_SCHEMA"], table["TABLE_NAME"]);
                MyCatCommand cmd = new MyCatCommand(sql, connection);
                using (MyCatDataReader reader = cmd.ExecuteReader())
                {
                    while (reader.Read())
                    {
                        string key_name = GetString(reader, reader.GetOrdinal("KEY_NAME"));
                        string col_name = GetString(reader, reader.GetOrdinal("COLUMN_NAME"));

                        if (restrictions != null)
                        {
                            if (restrictions.Length >= 4 && restrictions[3] != null &&
                                key_name != restrictions[3])
                            {
                                continue;
                            }
                            if (restrictions.Length >= 5 && restrictions[4] != null &&
                                col_name != restrictions[4])
                            {
                                continue;
                            }
                        }
                        MyCatSchemaRow row = dt.AddRow();
                        row["INDEX_CATALOG"]    = null;
                        row["INDEX_SCHEMA"]     = table["TABLE_SCHEMA"];
                        row["INDEX_NAME"]       = key_name;
                        row["TABLE_NAME"]       = GetString(reader, reader.GetOrdinal("TABLE"));
                        row["COLUMN_NAME"]      = col_name;
                        row["ORDINAL_POSITION"] = reader.GetValue(reader.GetOrdinal("SEQ_IN_INDEX"));
                        row["SORT_ORDER"]       = reader.GetString("COLLATION");
                    }
                }
            }

            return(dt);
        }
        public virtual MyCatSchemaCollection GetColumns(string[] restrictions)
        {
            MyCatSchemaCollection c = new MyCatSchemaCollection("Columns");

            c.AddColumn("TABLE_CATALOG", typeof(string));
            c.AddColumn("TABLE_SCHEMA", typeof(string));
            c.AddColumn("TABLE_NAME", typeof(string));
            c.AddColumn("COLUMN_NAME", typeof(string));
            c.AddColumn("ORDINAL_POSITION", typeof(ulong));
            c.AddColumn("COLUMN_DEFAULT", typeof(string));
            c.AddColumn("IS_NULLABLE", typeof(string));
            c.AddColumn("DATA_TYPE", typeof(string));
            c.AddColumn("CHARACTER_MAXIMUM_LENGTH", typeof(ulong));
            c.AddColumn("CHARACTER_OCTET_LENGTH", typeof(ulong));
            c.AddColumn("NUMERIC_PRECISION", typeof(ulong));
            c.AddColumn("NUMERIC_SCALE", typeof(ulong));
            c.AddColumn("CHARACTER_SET_NAME", typeof(string));
            c.AddColumn("COLLATION_NAME", typeof(string));
            c.AddColumn("COLUMN_TYPE", typeof(string));
            c.AddColumn("COLUMN_KEY", typeof(string));
            c.AddColumn("EXTRA", typeof(string));
            c.AddColumn("PRIVILEGES", typeof(string));
            c.AddColumn("COLUMN_COMMENT", typeof(string));

            // we don't allow restricting on table type here
            string columnName = null;

            if (restrictions != null && restrictions.Length == 4)
            {
                columnName      = restrictions[3];
                restrictions[3] = null;
            }
            MyCatSchemaCollection tables = GetTables(restrictions);

            foreach (MyCatSchemaRow row in tables.Rows)
            {
                LoadTableColumns(c, row["TABLE_SCHEMA"].ToString(),
                                 row["TABLE_NAME"].ToString(), columnName);
            }

            QuoteDefaultValues(c);
            return(c);
        }
        internal MyCatSchemaCollection CreateParametersTable()
        {
            MyCatSchemaCollection dt = new MyCatSchemaCollection("Procedure Parameters");

            dt.AddColumn("SPECIFIC_CATALOG", typeof(string));
            dt.AddColumn("SPECIFIC_SCHEMA", typeof(string));
            dt.AddColumn("SPECIFIC_NAME", typeof(string));
            dt.AddColumn("ORDINAL_POSITION", typeof(Int32));
            dt.AddColumn("PARAMETER_MODE", typeof(string));
            dt.AddColumn("PARAMETER_NAME", typeof(string));
            dt.AddColumn("DATA_TYPE", typeof(string));
            dt.AddColumn("CHARACTER_MAXIMUM_LENGTH", typeof(Int32));
            dt.AddColumn("CHARACTER_OCTET_LENGTH", typeof(Int32));
            dt.AddColumn("NUMERIC_PRECISION", typeof(byte));
            dt.AddColumn("NUMERIC_SCALE", typeof(Int32));
            dt.AddColumn("CHARACTER_SET_NAME", typeof(string));
            dt.AddColumn("COLLATION_NAME", typeof(string));
            dt.AddColumn("DTD_IDENTIFIER", typeof(string));
            dt.AddColumn("ROUTINE_TYPE", typeof(string));
            return(dt);
        }