Summary: Refining Your Results总结：优化您的结果

Congratulations! You have completed this lesson. At this point in the course, you know: 
恭喜！您已完成本课程。此时，您已经知道：

• You can use the WHERE clause to refine your query results. 
  您可以使用 WHERE 子句来细化您的查询结果。
• The search condition of the WHERE clause uses a predicate to refine the search. 
  WHERE 子句的搜索条件使用谓词来细化搜索。
• You can use the wildcard character (%) as a substitute for unknown characters in a pattern. 
  您可以使用通配符 (%) 作为模式中未知字符的替代。
• You can use BETWEEN ... AND ... to specify a range of numbers. 
  您可以使用 BETWEEN ... AND ... 来指定一个数值范围。
• You can sort query results into ascending or descending order, using the ORDER BY clause to specify the column to sort on. 
  您可以将查询结果按升序或降序排序，使用 ORDER BY 子句指定排序的列。 
• You can group query results by using the GROUP BY clause.  
  您可以使用 GROUP BY 子句对查询结果进行分组。