本文實(shí)例總結(jié)了MySQL單表查詢常見操作。分享給大家供大家參考，具體如下：
創(chuàng)建fruits表：
CREATE TABLE fruits( f_id char(10) NOT NULL, s_id INT NOT NULL, f_name char(255) NOT NULL, f_price decimal(8,2) NOT NULL, PRIMARY KEY(f_id)) ;INSERT INTO fruits (f_id, s_id, f_name, f_price)VALUES('a1', 101,'apple',5.2),('b1',101,'blackberry', 10.2),('bs1',102,'orange', 11.2),('bs2',105,'melon',8.2),('t1',102,'banana', 10.3),('t2',102,'grape', 5.3),('o2',103,'coconut', 9.2),('c0',101,'cherry', 3.2),('a2',103, 'apricot',2.2),('l2',104,'lemon', 6.4),('b2',104,'berry', 7.6),('m1',106,'mango', 15.6),('m2',105,'xbabay', 2.6),('t4',107,'xbababa', 3.6),('m3',105,'xxtt', 11.6),('b5',107,'xxxx', 3.6);常用查詢：
SELECT * FROM fruits;select f_name,f_price from fruits;select f_name,f_price from fruits where f_price=10.2;select f_name,f_price from fruits where f_price<10;select * from fruits where s_id in (101,102) order by f_name;select * from fruits where s_id not in (101,102) order by f_name;select f_name,f_price from fruits where f_price between 2.00 and 10.20;select f_name,f_price from fruits where f_price not between 2.00 and 10.20;select f_name,f_price from fruits where f_name like "b%";select f_name,f_price from fruits where f_name like "%g%";select f_name,f_price from fruits where f_name like "b%y";select f_name,f_price from fruits where f_name like "____y";
創(chuàng)建customers表：
CREATE TABLE customers( c_id int NOT NULL AUTO_INCREMENT, c_name char(50) NOT NULL, c_address char(50) NULL, c_city char(50) NULL, c_zip char(10) NULL, c_contact char(50) NULL, c_email char(255) NULL, PRIMARY KEY (c_id));INSERT INTO customers(c_id, c_name, c_address, c_city, c_zip, c_contact, c_email)VALUES(10001, 'RedHook', '200 Street ', 'Tianjin', '300000', 'LiMing', 'LMing@163.com'),(10002, 'Stars', '333 Fromage Lane', 'Dalian', '116000', 'Zhangbo','Jerry@hotmail.com'),(10003, 'Netbhood', '1 Sunny Place', 'Qingdao', '266000', 'LuoCong', NULL),(10004, 'JOTO', '829 Riverside Drive', 'Haikou', '570000', 'YangShan', 'sam@hotmail.com');
常用查詢語句：
select c_id,c_name,c_email from customers where c_email is null;select c_id,c_name,c_email from customers where c_email is not null;select f_name,f_price from fruits where s_id=101 and f_price>=5;select f_name,f_price from fruits where s_id in (101,102) and f_price >=5 and f_name="apple";select f_name,f_price from fruits where s_id=101 or s_id=102;
使用in操作更加簡潔明了
select f_name,f_pricefrom fruitswhere s_id in (101 ,102);
字段不重復(fù)
SELECT DISTINCT s_id FROM fruits;select f_name from fruits ORDER BY f_name;
如果第一列數(shù)據(jù)中沒有相同值，將不再對第二列進(jìn)行排序。
SELECT f_name, f_priceFROM fruitsORDER BY f_name, f_price;
按價(jià)格降序排列,desc為降序，默認(rèn)為升序。
SELECT f_name, f_price FROM fruits ORDER BY f_price desc;SELECT f_name, f_price FROM fruits ORDER BY f_price desc,f_name;SELECT s_id, COUNT(*) AS Total FROM fruits GROUP BY s_id;SELECT s_id, GROUP_CONCAT(f_name) AS Names FROM fruits GROUP BY s_id;
使用having過濾分組
SELECT s_id, GROUP_CONCAT(f_name) AS NamesFROM fruitsGROUP BY s_id having count(f_name)>1;
在group by 子句中使用with rollup
SELECT s_id, COUNT(*) AS Total FROM fruits GROUP BY s_id WITH ROLLUP;SELECT * from fruits group by s_id,f_name;
創(chuàng)建orderitems表：
CREATE TABLE orderitems( o_num int NOT NULL, o_item int NOT NULL, f_id char(10) NOT NULL, quantity int NOT NULL, item_price decimal(8,2) NOT NULL, PRIMARY KEY (o_num,o_item)) ;INSERT INTO orderitems(o_num, o_item, f_id, quantity, item_price)VALUES(30001, 1, 'a1', 10, 5.2),(30001, 2, 'b2', 3, 7.6),(30001, 3, 'bs1', 5, 11.2),(30001, 4, 'bs2', 15, 9.2),(30002, 1, 'b3', 2, 20.0),(30003, 1, 'c0', 100, 10),(30004, 1, 'o2', 50, 2.50),(30005, 1, 'c0', 5, 10),(30005, 2, 'b1', 10, 8.99),(30005, 3, 'a2', 10, 2.2),(30005, 4, 'm1', 5, 14.99);
常用查詢語句：
SELECT o_num, SUM(quantity * item_price) AS orderTotalFROM orderitemsGROUP BY o_numHAVING SUM(quantity*item_price) >= 100;SELECT o_num, SUM(quantity * item_price) AS orderTotalFROM orderitemsGROUP BY o_numHAVING SUM(quantity*item_price) >= 100order by ordertotal;SELECT * From fruits LIMIT 8;
從第五行開始，讀取3行
SELECT * From fruits LIMIT 4,3;
【例.1】從fruits表中檢索所有字段的數(shù)據(jù)
SELECT * FROM fruits;SELECT f_id, s_id ,f_name, f_price FROM fruits;
【例.2】查詢當(dāng)前表中f_name列所有水果名稱，輸入如下語句：
SELECT f_name FROM fruits;
【例.3】例如，從fruits表中獲取f_name和f_price兩列，輸入如下語句：
SELECT f_name, f_price FROM fruits;
【例.4】查詢價(jià)格為10.2元的水果的名稱，輸入如下語句：
SELECT f_name, f_priceFROM fruitsWHERE f_price = 10.2;
【例.5】查找名稱為“apple”的水果的價(jià)格,輸入如下語句：
SELECT f_name, f_priceFROM fruitsWHERE f_name = 'apple';
【例.6】查詢價(jià)格小于10的水果的名稱，輸入如下語句：
SELECT f_name, f_priceFROM fruitsWHERE f_price < 10;
【例.7】s_id為101和102的記錄，輸入如下語句：
SELECT s_id,f_name, f_priceFROM fruitsWHERE s_id IN (101,102)ORDER BY f_name;
【例.8】查詢所有s_id不等于101也不等于102的記錄，輸入如下語句：
SELECT s_id,f_name, f_priceFROM fruitsWHERE s_id NOT IN (101,102)ORDER BY f_name;
【例.9】查詢價(jià)格在2.00元到10.5元之間水果名稱和價(jià)格
SELECT f_name, f_priceFROM fruitsWHERE f_price BETWEEN 2.00 AND 10.20;
【例.10】查詢價(jià)格在2.00元到10.5元之外的水果名稱和價(jià)格
SELECT f_name, f_priceFROM fruitsWHERE f_price NOT BETWEEN 2.00 AND 10.20;
【例.11】查找所有以‘b'字母開頭的水果，輸入如下語句：
SELECT f_id, f_nameFROM fruitsWHERE f_name LIKE 'b%';
【例.12】在fruits表中，查詢f_name中包含字母‘g'的記錄
SELECT f_id, f_nameFROM fruitsWHERE f_name LIKE '%g%';
【例.13】查詢以‘b'開頭，并以‘y'結(jié)尾的水果的名稱
SELECT f_nameFROM fruitsWHERE f_name LIKE 'b%y';
【例7.14】在fruits表中，查詢以字母‘y'結(jié)尾，且‘y'前面只有4個(gè)字母的記錄
SELECT f_id, f_nameFROM fruitsWHERE f_name LIKE '____y';
【例.15】查詢customers表中c_email為空的記錄的c_id、c_name和c_email字段值：
SELECT c_id, c_name,c_emailFROM customersWHERE c_email IS NULL;
【例.16】查詢customers表中c_email不為空的記錄的c_id、c_name和c_email字段值
SELECT c_id, c_name,c_emailFROM customersWHERE c_email IS NOT NULL;
【例.17】在fruits表中查詢s_id = ‘101'，并且f_price大于5的記錄價(jià)格和名稱
SELECT f_id, f_price, f_nameFROM fruitsWHERE s_id = '101' AND f_price >=5;
【例.18】在fruits表中查詢s_id = ‘101'或者'102'，并且f_price大于5，并且f_name='apple'的記錄價(jià)格和名稱
SELECT f_id, f_price, f_nameFROM fruitsWHERE s_id IN('101', '102') AND f_price >= 5 AND f_name = 'apple';【例.19】查詢s_id=101或者s_id=102的水果供應(yīng)商的f_price和f_name，SQL語句如下：
SELECT s_id,f_name, f_priceFROM fruitsWHERE s_id = 101 OR s_id = 102;
【例.20】查詢s_id=101或者s_id=102的水果供應(yīng)商的f_price和f_name
SELECT s_id,f_name, f_priceFROM fruitsWHERE s_id IN(101,102);
【例.21】查詢fruits表中s_id字段的值，并返回s_id字段值不得重復(fù)
SELECT DISTINCT s_id FROM fruits;
【例.22】查詢fruits表的f_name字段值，并對其進(jìn)行排序
select f_name from fruits ORDER BY f_name;
【例.23】查詢fruits表中的f_name和f_price字段，先按f_name排序，再按f_price排序
SELECT f_name, f_priceFROM fruitsORDER BY f_name, f_price;
【例.24】查詢fruits表中的f_name和f_price字段，對結(jié)果按f_price降序方式排序
SELECT f_name, f_priceFROM fruitsORDER BY f_price DESC;
【例.25】查詢fruits表，先按f_price降序排序，再按f_name字段升序排序，SQL語句如下：
SELECT f_price, f_nameFROM fruitsORDER BY f_price DESC, f_name;
【例.26】根據(jù)s_id對fruits表中的數(shù)據(jù)進(jìn)行分組
SELECT s_id, COUNT(*) AS TotalFROM fruitsGROUP BY s_id;
【例.27】根據(jù)s_id對fruits表中的數(shù)據(jù)進(jìn)行分組，將每個(gè)供應(yīng)商的水果名稱顯示出來
SELECT s_id, GROUP_CONCAT(f_name) AS NamesFROM fruitsGROUP BY s_id;
【例.28】根據(jù)s_id對fruits表中的數(shù)據(jù)進(jìn)行分組，并顯示水果種類大于1的分組信息
SELECT s_id, GROUP_CONCAT(f_name) AS NamesFROM fruitsGROUP BY s_id HAVING COUNT(f_name) > 1;
【例.29】根據(jù)s_id對fruits表中的數(shù)據(jù)進(jìn)行分組，并顯示記錄數(shù)量
SELECT s_id, COUNT(*) AS TotalFROM fruitsGROUP BY s_id WITH ROLLUP;
【例.30】根據(jù)s_id和f_name字段對fruits表中的數(shù)據(jù)進(jìn)行分組， SQL語句如下，
SELECT * from fruits group by s_id,f_name;
【例.31】查詢訂單價(jià)格大于100的訂單號和總訂單價(jià)格
SELECT o_num, SUM(quantity * item_price) AS orderTotalFROM orderitemsGROUP BY o_numHAVING SUM(quantity*item_price) >= 100;
【例.32】顯示fruits表查詢結(jié)果的前4行，輸入如下語句：
SELECT * From fruits LIMIT 4;
【例.33】在fruits 表中，使用LIMIT子句，返回從第5個(gè)記錄開始的，行數(shù)長度為3的記錄
SELECT * From fruits LIMIT 4, 3;
希望本文所述對大家MySQL數(shù)據(jù)庫計(jì)有所幫助。
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