2018/08/15--mysql数据库

SELECT Concat(RTrim(vend_name),' (', RTrim(vend_country),')') AS vend_title FROM vendors ORDER BY vend_name;

SELECT prod_id,quantity,item_price,quantity*item_price AS expanded_price FROM orderitems WHERE order_num=20005;

SELECT vend_name,Upper(vend_name) AS vend_name_upcase FROM vendors ORDER BY vend_name;

SELECT DISTINCT vend_country,Left(vend_country,3) AS vend_country_left_3 FROM vendors ORDER BY vend_country;

SELECT DISTINCT vend_country,Right(vend_country,3) AS vend_country_right_3 FROM vendors ORDER BY vend_country;

SELECT DISTINCT vend_country,Substring(vend_country,1,3) AS vend_country_substring_1_3 FROM vendors ORDER BY vend_country;

SELECT cust_name,cust_contact FROM customers WHERE cust_contact ="Y.Lie";

SELECT cust_name,cust_contact FROM customers WHERE Soundex(cust_contact)=Soundex("Y.Lie");

SELECT 3*2;

SELECT RTrim('abc      ');

SELECT NOW();

SELECT Left("hello",3);    //得到 "hel"

SELECT Right("hello",3); //得到"llo"

SELECT Substring("hello",1,2);//得到"he"

SELECT Locate("ell","hello"); //得到2

SELECT Length("hello');  //得到5

SELECT DISTINCT vend_country,Left(vend_country,3) AS vend_country_left_3 FROM vendors ORDER BY vend_country;

vend_coutnry	vend_country_left_3
England	Eng
France	Fra
USA	USA

 

SELECT DISTINCT vend_country,Right(vend_country,3) AS vend_country_right_3 FROM vendors ORDER BY vend_country;

vend_country	vend_country_right_3
England	and
France	nce
USA	USA

SELECT DISTINCT vend_country,Substring(vend_country,2,3) AS vend_country_substring_2_3 FROM vendors ORDER BY vend_country;

vend_country	vend_country_substring_2_3
England	ngl
France	ran
USA	SA

SELECT cust_name,cust_contact FROM customers WHERE cust_contact="Y.Lie";

SELECT cust_name,cust_contact FROM customers WHERE Soundex(cust_contact)=Soundex("Y.Lie");

cust_name	cust_contact
Coyote Inc.	Y Lee