Funções MySQL

Retorna o código ASCII da primeira letra do campo CustomerName:

SELECT  ASCII(CustomerName)  como  NumCodeOfFirstChar
FROM  Customers;

Retorna a string w3Número de caracteres do codebox

SELECT  CHAR_LENGTH(\3codebox)  como  LengthOfString;

Retorna a string w3Número de caracteres do codebox

SELECT  CHARACTER_LENGTH(\3codebox)  como  LengthOfString;

Combinação de várias strings

SELECT  CONCAT(\3codebox ", \

合并多个字符串，并添加分隔符：

SELECT CONCAT_WS("-",　"SQL",　"Tutorial",　"is",　"fun!")AS　ConcatenatedString;

返回字符串 c 在列表值中的位置：

SELECT FIELD("c",　"a",　"b",　"c",　"d",　"e");

返回字符串 c 在指定字符串中的位置：

SELECT FIND_IN_SET("c",　"a,b,c,d,e");

格式化数字 "#,###.##" 形式：

SELECT FORMAT(250500.5634,　2);　　　　　--　输出　250,500.56

从字符串第一个位置开始的 6 个字符替换为 w3codebox：

SELECT INSERT("google.com",　1,　6,　"w3codebox");　　--　输出：oldtoolbag.com

获取 b 在字符串 abc 中的位置：

SELECT LOCATE('st','myteststring');　　--　5

início da string

SELECT LOCATE('b',　'abc')　--　2

字符串 w3codebox 转换为小写：

SELECT LCASE('w3codebox')　--　w3codebox

Retorna a string w3codebox 中的前两个字符：

SELECT LEFT('w3codebox',2)　--　ru

字符串 w3codebox 转换为小写：

SELECT LOWER('w3codebox')　--　w3codebox

将字符串 xx 填充到 abc 字符串的开始处：

SELECT LPAD('abc',5,'xx')　--　xxabc

Remover os espaços em branco no início e no final da string w3codebox开始处的空格：

SELECT LTRIM("　　w3codebox")　AS　LeftTrimmedString;--　w3codebox

da string w3codebox na posição 2 posição(s) de corte 3caractere(s):

Extrair uma substringa de comprimento len a partir da posição n da string s, equivalente a SUBSTRING(s,n,len)3codebox",　2,　3) AS ExtractString;　--　UNO

início da string

Retorna a posição de b na string abc:　--　2

Converter a string w3Repetir a string s n vezes

codebox　três vezes:3codebox',3)　--　w3SELECT　REPEAT('w3SELECT　REPEAT('w3codebox

Substituir o caractere a pela letra x na string abc:

SELECT　REPLACE('abc','a','x')　--xbc

Inverter a ordem da string abc:

SELECT　REVERSE('abc')　--　cba

Retorna a string w3codebox　últimos dois caracteres:

SELECT　RIGHT('w3codebox',2)　--　ob

Preencher a string xx até o final da string abc:

SELECT　RPAD('abc',5,'xx')　--　abcxx

Remover os espaços em branco no início e no final da string w3codebox　ao final:

SELECT　RTRIM("w3codebox　　　　　")　AS　RightTrimmedString;　　　--　w3codebox

Retorna 10 Quantidade de espaços:

SELECT　SPACE(10);

Comparar strings:

SELECT　STRCMP("w3codebox",　"w3codebox");　　--　0

da string w3codebox na posição 2 posição(s) de corte 3caractere(s):

SELECT　SUBSTR("w3codebox",　2,　3) AS ExtractString;　--　UNO

da string w3codebox na posição 2 posição(s) de corte 3caractere(s):

SELECT SUBSTRING("w3codebox",　2,　3) AS ExtractString;　--　UNO

SELECT SUBSTRING_INDEX('a*b','*',1)　--　a
SELECT SUBSTRING_INDEX('a*b','*',-1)　　　　--　b
SELECT SUBSTRING_INDEX(SUBSTRING_INDEX('a*b*c*d*e','*',3),'*',-1)　　　　--　c

Remover os espaços em branco no início e no final da string w3codebox com espaços em branco no início e no final:

SELECT TRIM('                       w3codebox                       ') AS TrimmedString;

Converter a string w3codebox convertida para maiúsculas:

SELECT UCASE("w3codebox");　--　w3codebox

Converter a string w3codebox convertida para maiúsculas:

SELECT UPPER("w3codebox");　--　w3codebox

Retorna -1 do valor absoluto:

SELECT ABS(-1)　--　Retorna1

SELECT ACOS(0.25);

SELECT ASIN(0.25);

SELECT ATAN(2.5);

SELECT ATAN2(-0.8,　2);

Retorna a média do campo Price na tabela Products:

SELECT AVG(Price) AS AveragePrice FROM Products;

SELECT CEIL(1.5)　--　Retorna2

SELECT CEILING(1.5);　--　Retorna2

SELECT COS(2);

SELECT COT(6);

Retorna o número total de registros do campo products na tabela Products:

SELECT COUNT(ProductID) AS NumberOfProducts FROM Products;

SELECT DEGREES(3.1415926535898)　--　180

Calcula 10 dividido por 5:

SELECT　10　DIV　5;　　--　2

Calcula o cubo de e:

SELECT EXP(3)　--　20.085536923188

menor ou igual a 1.5 do inteiro:

SELECT FLOOR(1.5)　--　Retorna1

Retorna o maior valor da lista de números a seguir:

SELECT GREATEST(3,　12,　34,　8,　25);　--　34

Retorna o maior valor da lista de strings a seguir:

SELECT GREATEST("Google", "w3codebox", "Apple");　　　--　w3codebox

Retorna o menor valor da lista de números a seguir:

SELECT LEAST(3,　12,　34,　8,　25);　--　3

Retorna o menor valor da lista de strings a seguir:

SELECT LEAST("Google", "w3codebox", "Apple");　　　--　Apple

Retorna 2 do logaritmo natural:

SELECT LN(2);　　--　0.6931471805599453

SELECT LOG(20.085536923188)　--　3
SELECT LOG(2,　4);　--　2

SELECT LOG10(100)　--　2

Retorna o logaritmo com base 2 com base 6 do logaritmo:

SELECT LOG2(6);　　--　2.584962500721156

Retorna o valor máximo do campo Price na tabela de dados Products:

SELECT MAX(Price) AS LargestPrice FROM Products;

Retorna o valor mínimo do campo Price na tabela de dados Products:

SELECT MIN(Price) AS MinPrice FROM Products;

5 dividido por 2 o resto:

SELECT MOD(5,2)　--　1

SELECT PI()　--3.141593

2 de 3 potência:

SELECT POW(2,3)　--　8

2 de 3 potência:

SELECT POWER(2,3)　--　8

180 graus convertidos para radianos:

SELECT RADIANS(180)　--　3.1415926535898

SELECT RAND()　--0.93099315644334

SELECT ROUND(1.23456)　--1

SELECT SIGN(-10)　--　(-1)

SELECT SIN(RADIANS(30))　--　0.5

25 a raiz quadrada:

SELECT SQRT(25)　--　5

calcular a soma do campo Quantity na tabela OrderDetails:

SELECT SUM(Quantity) AS TotalItemsOrdered FROM OrderDetails;

SELECT TAN(1.75);　　--　-5.52037992250933

SELECT TRUNCATE(1.23456,3)　--　1.234

SELECT ADDDATE("2017-06-15", INTERVAL　10　DAY);
->2017-06-25

adicionar 5 segundos:

SELECT ADDTIME('2011-11-11　11:11:11',　5);
->2011-11-11　11:11:16　(秒)

adicionar 2 horas, 10 minutos, 5 segundos:

SELECT ADDTIME("2020-06-15　09:34:21",　"2:10:5);　
->　2020-06-15　11:44:26

SELECT CURDATE();
->　2018-09-19

SELECT CURRENT_DATE();
->　2018-09-19

SELECT CURRENT_TIME();
->　19:59:02

SELECT CURRENT_TIMESTAMP();
->　2018-09-19　20:57:43

SELECT CURTIME();
->　19:59:02

SELECT DATE('2017-06-15);　　　　
->　2017-06-15

SELECT DATEDIFF('2001-01-01','2001-02-02")
->　-32

SELECT ADDDATE('2011-11-11　11:11:11',1)
->　2011-11-12　11:11:11　　　　(默认是天)
SELECT ADDDATE('2011-11-11　11:11:11', INTERVAL　5　MINUTO)
->　2011-11-11　11:16:11　(Os valores do TYPE são semelhantes aos da função listada acima)

SELECT DATE_FORMAT('2011-11-11　11:11:11','%Y-%m-%d %r')
->　2011-11-11　11:11:11　AM

O campo OrderDate da tabela Orders subtraído 2 dias:

SELECT OrderId,DATE_SUB(OrderDate,INTERVAL　2　DAY) AS OrderPayDate
FROM Orders

SELECT DAY('2017-06-15);　　
->　15

SELECT DAYNAME('2011-11-11　11:11:11")
->Friday

SELECT DAYOFMONTH('2011-11-11　11:11:11")
->11

SELECT DAYOFWEEK('2011-11-11　11:11:11")
->6

SELECT DAYOFYEAR('2011-11-11　11:11:11")
->315

• MICROSEGUNDO

• SEGUNDO

• MINUTO

• HORA

• DIA

• SEMANA

• MÊS

• TRIMESTRE

• ANO

• SEGUNDO_MICROSEGUNDO

• MINUTE_MICROSECOND

• MINUTE_SECOND

• HOUR_MICROSECOND

• HOUR_SECOND

• HOUR_MINUTE

• DAY_MICROSECOND

• DAY_SECOND

• DAY_MINUTE

• DAY_HOUR

• YEAR_MONTH

SELECT EXTRACT(MINUTE FROM '2011-11-11　11:11:11")　
->　11

SELECT FROM_DAYS(1111)
-> 0003-01-16

SELECT HOUR('1:2:3")
->　1

SELECT LAST_DAY("2017-06-20");
->　2017-06-30

SELECT LOCALTIME()
->　2018-09-19　20:57:43

SELECT LOCALTIMESTAMP()
->　2018-09-19　20:57:43

SELECT MAKEDATE(2017,　3);
->　2017-01-03

SELECT MAKETIME(11,　35,　4);
->　11:35:04

SELECT MICROSECOND("2017-06-20 09:34:00.000023);
->　23

SELECT MINUTE('1:2:3")
->　2

SELECT MONTHNAME('2011-11-11　11:11:11")
-> Novembro

SELECT MONTH('2011-11-11　11:11:11")
->11

SELECT NOW()
->　2018-09-19　20:57:43

SELECT PERIOD_ADD(201703,　5);　　　
->　201708

SELECT PERIOD_DIFF(201710,　201703);
->　7

SELECT QUARTER('2011-11-11　11:11:11")
->　4

SELECT　SECOND('1:2:3")
->　3

SELECT　SEC_TO_TIME(4320)
-> 01:12:00

SELECT　STR_TO_DATE("August　10　2017",　"%M　%d　%Y");
->　2017-08-10

SELECT　SUBDATE('2011-11-11　11:11:11',　1)
->2011-11-10　11:11:11　(默认是天)

SELECT　SUBTIME('2011-11-11　11:11:11',　5)
->2011-11-11　11:11:06　(秒)

SELECT　SYSDATE()
->　2018-09-19　20:57:43

SELECT　TIME('19:30:10);
->　19:30:10

SELECT　TIME_FORMAT('11:11:11('%r')
11:11:11　AM

SELECT　TIME_TO_SEC('1:12:00')
->　4320

SELECT　TIMEDIFF("13:10:11",　"13:10:10);
->　00:00:01

SELECT　TIMESTAMP("2017-07-23",　　"13:10:11);
->　2017-07-23　13:10:11

SELECT　TO_DAYS('0001-01-01　01:01:01")
->　366

SELECT　WEEK('2011-11-11　11:11:11")
->　45

SELECT　WEEKDAY("2017-06-15);
->　3

SELECT　WEEKOFYEAR('2011-11-11　11:11:11")
->　45

SELECT　YEAR("2017-06-15);
->　2017

SELECT YEARWEEK("2017-06-15);
->　201724

15 de 2 código de bases:

SELECT BIN(15);　--　1111

SELECT BINARY "w3codebox";
-> w3codebox

CASE expressão
　　　　QUANDO condition1　ENTÃO result1
　　　　QUANDO condition2　ENTÃO result2
　　　...
　　　　QUANDO conditionN ENTÃO resultN
　　　　ELSE result
FIM

SELECT CASE　
　　QUANDO　1　> 0
　　ENTÃO '1　> 0'
　　QUANDO　2　> 0
　　ENTÃO '2　> 0'
　　ELSE '3　> 0'
　　FIM
->1　> 0

Conversão de data de string para data:

SELECT CAST("2017-08-29" AS DATE);
->　2017-08-29

SELECT COALESCE(NULL, NULL, NULL, 'oldtoolbag.com, NULL, 'google.com');
-> oldtoolbag.com

SELECT CONNECTION_ID();
->　4292835

SELECT CONV(15,　10,　2);
->　1111

SELECT CHARSET('ABC')
-> utf-8　　　　
SELECT CHARSET(CONVERT('ABC' USING gbk))
-> gbk

SELECT CURRENT_USER();
-> guest@%

SELECT DATABASE();　　　
-> w3codebox

SELECT IF(1　0, 'correto', 'errado')　　　　
->Correto

SELECT IFNULL(null,'Hello Word')
->Hello Word

SELECT ISNULL(NULL);
->1

SELECT LAST_INSERT_ID();
->6

SELECT NULLIF(25,　25);
->

SELECT SESSION_USER();
-> guest@%

SELECT SYSTEM_USER();
-> guest@%

SELECT USER();
-> guest@%

SELECT VERSION();
->　5.6.34