MySQLexpress |
SQL SERVERspa |
CHAR_LENGTH(str)ci |
LEN(character_expression)rem |
CONCAT(str1,str2,...)string |
str1+str2it |
INSERT(str,pos,len,newstr)io |
STUFF ( character_expression , start , length ,character_expression )table |
LOCATE(substr,str [,pos])class |
CHARINDEX ( expression1 ,expression2 [ , start_location ] )test |
LEFT(str,len) |
LEFT ( character_expression , integer_expression ) |
LENGTH(str) |
DATALENGTH ( expression ) |
LTRIM(str) |
LTRIM(character expression) |
REPEAT(str,count) |
REPLICATE(character_expression,times) |
REPLACE(str,from_str,to_str) |
REPLACE(character_expression,searchstring,replacementstring) |
REVERSE(str) |
REVERSE(character_expression) |
RIGHT(str,len) |
RIGHT(character_expression,integer_expression) |
RTRIM(str) |
RTRIM(character expression) |
SUBSTRING(str,pos,len) |
SUBSTRING(character_expression, position, length) |
SUBSTRING_INDEX(str,delim,count) |
無 |
TRIM([{BOTH | LEADING | TRAILING} [remstr] FROM] str) |
無 |
MySQL |
SQL SERVER |
CURDATE() |
無 |
CURTIME() |
無 |
DATE(expr) |
無 |
DATE_ADD(date,INTERVAL expr unit) |
DATEADD(datepart, number, date) |
DAY(date) |
DATEPART('dd', date) |
HOUR(time) |
DATEPART('hh', date) |
MINUTE(time) |
DATEPART('mi', date) |
MONTH(date) |
DATEPART('mm', date) |
NOW() |
GETDATE() |
SECOND(time) |
DATEPART('ss', date) |
TIME(expr) |
無 |
YEAR(date) |
DATEPART('yy', date) |
若是表Test中有A、B兩個字段,建立視圖以下
Create view v_test as select * from Test;
此時視圖實際的定義以下:
Create view v_test as select A,B from Test;
也就是說Test未來增長的字段並不在視圖裏面。
在SQL SERVER中,若是建立視圖以下
Create view v_test as select * from Test;
此時視圖實際的定義就是:
Create view v_test as select * from Test;
視圖中永遠都包含Test的全部字段。