The substr function is a function that returns a substring from a string. syntax substr([input],[start],[length]) or substr([input],[start]) or With input the String to take a substring from, start is the starting position where 1 is the first character. (if you pass 0, this wi...
If thestart_positionis 0, the begin of the substring will be at the first character of thestr. In case thestart_positionis positive, theSUBSTR()function will count from the beginning of thestrto determine the first character of the substring. ...
This example shows the last character of the string. SELECT'Database Star',SUBSTR('Database Star',-1,5)ASSUBFROMDUAL; Result: As the start_position is -1, it starts at the first character before the end of the string. Because the length is greater than 1, it returns the whole subst...
--The following example examines the string, looking for the first substring bounded by commas.--Oracle Database searches for a comma followed by one or more occurrences of non-comma characters followed by a comma.--Oracle returns the substring, including the leading and trailing commas.SELECTREG...
它产生了4次匹配:First Match=Jerry Seinfeld; Second Match=Elaine Benes; Third Match=Cosmo Kramer; Fourth Match=George Costanza 每一次匹配都对应了一个lastName组: 第1次匹配:lastName group=Seinfeld 第2次匹配:lastName group=Benes 第3次匹配:lastName group=Kramer ...
(char, position [, substring_length ]) Parameters: Behavior when position: If the position is 0, then it is treated as 1. If the position is positive, then Oracle counts from the beginning of char to find the first character. If the position is negative, then Oracle counts backward from...
Ifpositionis positive, then Oracle Database counts from the beginning ofcharto find the first character. Ifpositionis negative, then Oracle counts backward from the end ofchar. Ifsubstring_lengthis omitted, then Oracle returns all characters to the end ofchar. Ifsubstring_lengthis less than 1,...
Empty Substring:-- The following SQL query uses the INSTR function to locate the position of the first space character (' ') in the string 'THIS IS THE THING'. SELECT INSTR('THIS IS THE THING', -- The string in which we are searching for the space character. ' ' -- The substring...
and substring((select @@version),22,4)='2008'--适用于无回显模式,后面的2008就是数据库版本, 返回正常就是2008的复制代码第一条语句执行效果图(类似):第二条语句执行效果图:(如果是 2008的话就返回正常) ③获取所有数据库的个数 (一下3条语句可供选择使用) ...
Instead of returning the position of the substring, it returns a portion of the source string that matches the regular expression. Syntax The following illustrates the syntax of the Oracle REGEXP_SUBSTR() function: REGEXP_SUBSTR(source_string, pattern [, start_position [, occurrence [, match_...