Method getDatashareTableColumns

backend/plugin/db/redshift/sync.go:454–503

getDatashareTableColumns gets the columns of tables in datashare database.

(txn *sql.Tx)

// getDatashareTableColumns gets the columns of tables in datashare database.
func (d *Driver) getDatashareTableColumns(txn *sql.Tx) (map[db.TableKey][]*storepb.ColumnMetadata, error) {
	columnsMap := make(map[db.TableKey][]*storepb.ColumnMetadata)

	query := `
	SELECT
		schema_name,
		table_name,
		column_name,
		data_type,
		ordinal_position,
		column_default,
		is_nullable,
		character_maximum_length
	FROM SVV_ALL_COLUMNS
	WHERE database_name = $1;`
	rows, err := txn.Query(query, d.databaseName)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	for rows.Next() {
		column := &storepb.ColumnMetadata{}
		var schemaName, tableName, nullable string
		var defaultStr sql.NullString
		var varcharMaxLength sql.NullInt32
		if err := rows.Scan(&schemaName, &tableName, &column.Name, &column.Type, &column.Position, &defaultStr, &nullable, &varcharMaxLength); err != nil {
			return nil, err
		}
		if defaultStr.Valid {
			// Store in Default field (migration from DefaultExpression to Default)
			column.Default = defaultStr.String
		}
		isNullBool, err := util.ConvertYesNo(nullable)
		if err != nil {
			return nil, err
		}
		column.Nullable = isNullBool
		if column.Type == "character varying" && varcharMaxLength.Valid {
			column.Type = fmt.Sprintf("varchar(%d)", varcharMaxLength.Int32)
		}

		key := db.TableKey{Schema: schemaName, Table: tableName}
		columnsMap[key] = append(columnsMap[key], column)
	}
	if err := rows.Err(); err != nil {
		return nil, err
	}

	return columnsMap, nil
}

// getViews gets all views of a database.
func getViews(txn *sql.Tx, columnMap map[db.TableKey][]*storepb.ColumnMetadata) (map[string][]*storepb.ViewMetadata, error) {