整理MySql常用查詢語句(23種)
廢話不多了,直接貼代碼了
一查詢數(shù)值型數(shù)據(jù):
SELECT * FROM tb_name WHERE sum > 100;
查詢謂詞:>,=,<,<>,!=,!>,!<,=>,=<
二查詢字符串
SELECT * FROM tb_stu WHERE sname = '小劉' SELECT * FROM tb_stu WHERE sname like '劉%' SELECT * FROM tb_stu WHERE sname like '%程序員' SELECT * FROM tb_stu WHERE sname like '%PHP%'
三查詢?nèi)掌谛蛿?shù)據(jù)
SELECT * FROM tb_stu WHERE date = '2011-04-08'
注:不同數(shù)據(jù)庫對(duì)日期型數(shù)據(jù)存在差異:
(1)MySQL:SELECT * from tb_name WHERE birthday = '2011-04-08' (2)SQL Server:SELECT * from tb_name WHERE birthday = '2011-04-08' (3)Access:SELECT * from tb_name WHERE birthday = #2011-04-08#
四查詢邏輯型數(shù)據(jù)
SELECT * FROM tb_name WHERE type = 'T' SELECT * FROM tb_name WHERE type = 'F'
邏輯運(yùn)算符:and or not
五查詢非空數(shù)據(jù)
SELECT * FROM tb_name WHERE address <>'' order by addtime desc
注:<>相當(dāng)于PHP中的!=
六利用變量查詢數(shù)值型數(shù)據(jù)
SELECT * FROM tb_name WHERE id = '$_POST[text]'
注:利用變量查詢數(shù)據(jù)時(shí),傳入SQL的變量不必用引號(hào)括起來,因?yàn)镻HP中的字符串與數(shù)值型數(shù)據(jù)進(jìn)行連接時(shí),程序會(huì)自動(dòng)將數(shù)值型數(shù)據(jù)轉(zhuǎn)變成字符串,然后與要連接的字符串進(jìn)行連接
七利用變量查詢字符串?dāng)?shù)據(jù)
SELECT * FROM tb_name WHERE name LIKE '%$_POST[name]%'
完全匹配的方法"%%"表示可以出現(xiàn)在任何位置
八查詢前n條記錄
SELECT * FROM tb_name LIMIT 0,$N;
limit語句與其他語句,如order by等語句聯(lián)合使用,會(huì)使用SQL語句千變?nèi)f化,使程序非常靈活
九查詢后n條記錄
SELECT * FROM tb_stu ORDER BY id ASC LIMIT $n
十查詢從指定位置開始的n條記錄
SELECT * FROM tb_stu ORDER BY id ASC LIMIT $_POST[begin],$n
注意:數(shù)據(jù)的id是從0開始的
十一查詢統(tǒng)計(jì)結(jié)果中的前n條記錄
SELECT * ,(yw+sx+wy) AS total FROM tb_score ORDER BY (yw+sx+wy) DESC LIMIT 0,$num
十二查詢指定時(shí)間段的數(shù)據(jù)
SELECT 要查找的字段 FROM 表名 WHERE 字段名 BETWEEN 初始值 AND 終止值
SELECT * FROM tb_stu WHERE age BETWEEN 0 AND 18
十三按月查詢統(tǒng)計(jì)數(shù)據(jù)
SELECT * FROM tb_stu WHERE month(date) = '$_POST[date]' ORDER BY date ;
注:SQL語言中提供了如下函數(shù),利用這些函數(shù)可以很方便地實(shí)現(xiàn)按年、月、日進(jìn)行查詢
year(data):返回data表達(dá)式中的公元年分所對(duì)應(yīng)的數(shù)值
month(data):返回data表達(dá)式中的月分所對(duì)應(yīng)的數(shù)值
day(data):返回data表達(dá)式中的日期所對(duì)應(yīng)的數(shù)值
十四查詢大于指定條件的記錄
SELECT * FROM tb_stu WHERE age>$_POST[age] ORDER BY age;
十五查詢結(jié)果不顯示重復(fù)記錄
SELECT DISTINCT 字段名 FROM 表名 WHERE 查詢條件
注:SQL語句中的DISTINCT必須與WHERE子句聯(lián)合使用,否則輸出的信息不會(huì)有變化 ,且字段不能用*代替
十六NOT與謂詞進(jìn)行組合條件的查詢
(1)NOT BERWEEN … AND … 對(duì)介于起始值和終止值間的數(shù)據(jù)時(shí)行查詢 可改成 <起始值 AND >終止值
(2)IS NOT NULL 對(duì)非空值進(jìn)行查詢
(3)IS NULL 對(duì)空值進(jìn)行查詢
(4)NOT IN 該式根據(jù)使用的關(guān)鍵字是包含在列表內(nèi)還是排除在列表外,指定表達(dá)式的搜索,搜索表達(dá)式可以是常量或列名,而列名可以是一組常量,但更多情況下是子查詢
十七顯示數(shù)據(jù)表中重復(fù)的記錄和記錄條數(shù)
SELECT name,age,count(*) ,age FROM tb_stu WHERE age = '19' group by date
十八對(duì)數(shù)據(jù)進(jìn)行降序/升序查詢
SELECT 字段名 FROM tb_stu WHERE 條件 ORDER BY 字段 DESC 降序
SELECT 字段名 FROM tb_stu WHERE 條件 ORDER BY 字段 ASC 升序
注:對(duì)字段進(jìn)行排序時(shí)若不指定排序方式,則默認(rèn)為ASC升序
十九對(duì)數(shù)據(jù)進(jìn)行多條件查詢
SELECT 字段名 FROM tb_stu WHERE 條件 ORDER BY 字段1 ASC 字段2 DESC …
注意:對(duì)查詢信息進(jìn)行多條件排序是為了共同限制記錄的輸出,一般情況下,由于不是單一條件限制,所以在輸出效果上有一些差別。
二十對(duì)統(tǒng)計(jì)結(jié)果進(jìn)行排序
函數(shù)SUM([ALL]字段名) 或 SUM([DISTINCT]字段名),可實(shí)現(xiàn)對(duì)字段的求和,函數(shù)中為ALL時(shí)為所有該字段所有記錄求和,若為DISTINCT則為該字段所有不重復(fù)記錄的字段求和
如:
SELECT name,SUM(price) AS sumprice FROM tb_price GROUP BY name SELECT * FROM tb_name ORDER BY mount DESC,price ASC
二十一單列數(shù)據(jù)分組統(tǒng)計(jì)
SELECT id,name,SUM(price) AS title,date FROM tb_price GROUP BY pid ORDER BY title DESC
注:當(dāng)分組語句group by排序語句order by同時(shí)出現(xiàn)在SQL語句中時(shí),要將分組語句書寫在排序語句的前面,否則會(huì)出現(xiàn)錯(cuò)誤
二十二多列數(shù)據(jù)分組統(tǒng)計(jì)
多列數(shù)據(jù)分組統(tǒng)計(jì)與單列數(shù)據(jù)分組統(tǒng)計(jì)類似
SELECT *,SUM(字段1*字段2) AS (新字段1) FROM 表名 GROUP BY 字段 ORDER BY 新字段1 DESC
SELECT id,name,SUM(price*num) AS sumprice FROM tb_price GROUP BY pid ORDER BY sumprice DESC
注:group by語句后面一般為不是聚合函數(shù)的數(shù)列,即不是要分組的列
二十三多表分組統(tǒng)計(jì)
SELECT a.name,AVG(a.price),b.name,AVG(b.price) FROM tb_demo058 AS a,tb_demo058_1 AS b WHERE a.id=b.id GROUP BY b.type;
就是內(nèi)容就是本人給大家整理的MySql常用查詢語句(23種),希望能幫助到大家。
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