MySQL必知必会(使用函数处理数据)

#文本处理函数
SELECT vend_name, Upper(vend_name) AS vend_name_upcase FROM vendors
ORDER BY vend_name;

SELECT cust_name, cust_contact FROM customers
WHERE Soundex(cust_contact) = Soundex('Y Lie'); #Soundex()匹配所有发音类似于Y.Lie的联系名

#日期和时间处理函数
SELECT cust_id, order_num FROM orders
WHERE order_date = '2005-09-01'; #这种全行匹配不可靠，下面的用一些日期函数处理更准确。比如不能匹配带有时分秒的列

SELECT cust_id, order_num FROM orders
WHERE Date(order_date) = '2005-09-01';

SELECT cust_id, order_num FROM orders
WHERE Date(order_date) BETWEEN '2005-09-01' AND '2005-09-30';

SELECT cust_id, order_num FROM orders
WHERE Year(order_date) = 2005 AND Month(order_date) = 9;

常用的文本处理函数：

常用的日期和时间处理函数：

常用的数值处理函数：