网站建设设计理念,wordpress口腔,做生存分析的网站有哪些,北京昌平区此为自用查询语句1.selectSELECT column1,column2 FROM table1;常用的格式惯例#xff1a;大写了SELECT和FROM#xff0c;而将表名和列名小写#xff1b;通常在列名中使用下划线#xff0c;避免使用空格#xff1b;在每个语句末尾添加分号#xff1b;SQL不区分大小写。2.…此为自用查询语句1.selectSELECT column1,column2 FROM table1;常用的格式惯例大写了SELECT和FROM而将表名和列名小写通常在列名中使用下划线避免使用空格在每个语句末尾添加分号SQL不区分大小写。2.limitSELECT name,director FROM movies
LIMIT 15;3.order bySELECT name, FROM,film_year,ticket_price FROM movies
ORDER BY film_year DESC,ticket_price DESC
LIMIT 5;DESC是倒序4.where用在order by之前SELECT name,film_year FROM movies
WHERE name 哈利波特
ORDER BY film_year;5.派生列假如表movies里没有列count、countrySELECT film_year,ticket_price,film_year/ticket_price AS countEnglandAS country
FROM movies
WHERE name 哈利波特
ORDER BY film_year
LIMIT 5;逻辑运算符1.like.SELECT name FROM movies
WHERE name LIKE %哈利%;2.in.SELECT name,director FROM movies
WHERE name IN (哈利波特,魔戒);3.not.SELECT name FROM movies
WHERE name NOT LIKE 哈利%;SELECT name,director FROM movies
WHERE name NOT IN (哈利波特,魔戒);4.and 与 betweenSELECT name, director FROM movies
WHERE film_year 2000 and name 哈利波特;SELECT name,director FROM movies
WHERE film_day NOT BETWEEN 2000-01-01 AND 2010-01-01;between包含端点值但对于时间2010-01-01是2010-01-01 0:00:005.or.SELECT name,director FROM movies
WHERE (film_year 2000 OR film_year 2010) AND name 哈利波特
ORDER BY film_year;
