Method updateTable

engine/engine.go:171–215

(command *ast.UpdateCommand)

}

func (engine *DbEngine) updateTable(command *ast.UpdateCommand) error {
	table, exist := engine.Tables[command.Name.Token.Literal]

	if !exist {
		return &TableDoesNotExistError{command.Name.Token.Literal}
	}

	columns := table.Columns

	// TODO: This could be optimized
	mappedChanges := make(map[int]ast.Anonymitifier)
	for updatedCol, newValue := range command.Changes {
		for colIndex := 0; colIndex < len(columns); colIndex++ {
			if columns[colIndex].Name == updatedCol.Literal {
				mappedChanges[colIndex] = newValue
				break
			}
			if colIndex == len(columns)-1 {
				return &ColumnDoesNotExistError{tableName: command.Name.GetToken().Literal, columnName: updatedCol.Literal}
			}
		}
	}

	numberOfRows := len(columns[0].Values)
	for rowIndex := 0; rowIndex < numberOfRows; rowIndex++ {
		if command.HasWhereCommand() {
			fulfilledFilters, err := isFulfillingFilters(getRow(table, rowIndex), command.WhereCommand.Expression, command.WhereCommand.Token.Literal)
			if err != nil {
				return err
			}
			if !fulfilledFilters {
				continue
			}
		}
		for colIndex, value := range mappedChanges {
			interfaceValue, err := getInterfaceValue(value.GetToken())
			if err != nil {
				return err
			}
			table.Columns[colIndex].Values[rowIndex] = interfaceValue
		}
	}

	return nil
}

// insertIntoTable - Insert row of values into the table
func (engine *DbEngine) insertIntoTable(command *ast.InsertCommand) error {