您好,太多了,一般常见的有
1.AVG():返回数值列的平均值,不包括null值;
2.COUNT():返回匹配指定条件的行数;
SELECT COUNT(Store_Name) FROM Store_Information WHERE Store_Name IS NOT NULL;
SELECT COUNT(DISTINCT Store_Name) FROM Store_Information;
3. MAX():返回一列中的最大值,null值不包括在计算中;
SELECT MAX(Salary) FROM Store_Information;
4. MIN():返回一列中的最小值,null值不包括在计算中;
SELECT MIN(Salary) FROM Store_Information;
5. SUM() :返回数值列的总数(总额);
SELECT SUM(Sales) FROM Store_Information;
6. FIRST():返回指定的字段中第一个记录的值;
SELECT FIRST(OrderPrice) AS FirstOrderPrice FROM Orders;
7. LAST():返回指定的字段中最后一个记录的值;
SELECT LAST(OrderPrice) AS LastOrderPrice FROM Orders;
8. UCASE():把字段的值转换为大写;
SELECT UCASE(LastName) AS LN, FirstName FROM Persons;
9. LCASE():把字段的值转换为小写;
SELECT LCASE(LastName) AS LN, FirstName FROM Persons;
10. MID():从文本字段中提取字符;
SELECT MID(City,1,3) AS SC FROM Persons;
11. LEN():返回文本字段中值的长度;
SELECT LEN(City) AS LengthOfCity FROM Persons;
12. ROUND():把数值字段舍入为指定的小数位数;
SELECT ProductName, ROUND(UnitPrice,1) AS UP FROM Products;
13. NOW():返回当前的日期和时间;
SELECT ProductName, UnitPrice, Now() as PerDate FROM Products;
14. FORMAT():对字段的显示进行格式化;
SELECT ProductName, UnitPrice, FORMAT(Now(),'YYYY-MM-DD') as PerDate FROM Products
版权声明:本文内容由阿里云实名注册用户自发贡献,版权归原作者所有,阿里云开发者社区不拥有其著作权,亦不承担相应法律责任。具体规则请查看《阿里云开发者社区用户服务协议》和《阿里云开发者社区知识产权保护指引》。如果您发现本社区中有涉嫌抄袭的内容,填写侵权投诉表单进行举报,一经查实,本社区将立刻删除涉嫌侵权内容。