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RSS订阅原创 sqlzoo--Self JION
1.How many stops are in the database. SELECT COUNT(*) FROM stops 2.Find the id value for the stop ‘Craiglockhart’ SELECT id FROM stops WHERE name = ‘Craiglockhart’ 3.Give the id and the name f...
2018-07-31 14:45:31
336
原创 sqlzoo--Using Null
这里涉及两个表： teacher(id,dept,name,phone,mobile); dept(id,name); 1.List the teachers who have NULL for their department. SELECT name FROM teacher WHERE dept IS NULL 2.Note the INNER JOIN misses the...
2018-07-30 23:38:52
216
原创 sqlzoo练习--MORE JION
The JOIN operation1.List the films where the yr is 1962 [Show id, title] 2.Give year of ‘Citizen Kane’. 3.List all of the Star Trek movies, include the id, title and yr (all of these movies includ...
2018-07-30 16:04:33
331
原创 sqlzoo练习--JION
1.Modify it to show the matchid and player name for all goals scored by Germany. To identify German players, check for: teamid = ‘GER’ SELECT matchid,player FROM goal WHERE teamid = ‘GER’ 2.Show ...
2018-07-29 19:00:46
354
原创 sqlzool练习--SELECT and COUNT
1.Show the total population of the world. SELECT SUM(population) FROM world 2.List all the continents - just once each. SELECT continent FROM world GROUP BY continent 3.Give the total GDP...
2018-07-28 23:04:36
1313
原创 sqlzoo练习--SELECT in SELECT
SELECT in SELECT1.List each country name where the population is larger than that of ‘Russia’. SELECT name FROM world WHERE population >(SELECT population ...
2018-07-28 17:20:23
2847
原创 sqlzoo的练习----SELECT from Nobel
SELECT from Nobel1.Change the query shown so that it displays Nobel prizes for 1950. SELECT yr, subject, winner FROM nobel WHERE yr = 1950 2.Show who won the 1962 prize for Literature. SELECT...
2018-07-28 15:03:36
976
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