Oracle intercepts strings and lookup strings, and uses the combined interception of specific characters

The Oracle Intercept character (SUBSTR), which retrieves the character position (instr), when the then else End statement uses the favorite
Common functions: Substr and InStr
1.SUBSTR (String,start_position,[length]) to substring, return string
Explanation: String meta strings
Start_position start position (starting from 0)
Length optional, number of substrings
For example:
substr ("ABCDEFG", 0); return: ABCDEFG, intercept all characters
substr ("ABCDEFG", 2); return: CDEFG, intercept all characters after starting with C
substr ("ABCDEFG", 0, 3); return: ABC, intercept starting from a 3 characters
substr ("ABCDEFG", 0, 100); Return: abcdefg,100 The maximum number of preprocessed strings is returned, although it exceeds the length of the preprocessed string, but does not affect the return result.
substr ("ABCDEFG",-3); Return: EFG, note parameter-3, a negative value indicates that the string is not changed from the beginning of the tail.

2.INSTR (string,substring,position,ocurrence) Find string position
Explanation: string: source string
SubString: substring to find
Position: Where to find start
Ocurrence: A substring of the first occurrence of a source string
For example:
INSTR (' CORPORATE floor ', ' or ', 3, 2), the source string is ' CORPORATE floor ', the target string is ' OR ', the starting position is 3, the position of the 2nd match is taken, and the return result is 14 '

To test a field instance:

Table: cheyang.content= ' request= "" packid= "" packplanid= "100003624470" sflag= "1" '

Requirement: Intercept Packplanid's Vlaue value

Select substr (Planid, 0, InStr (Planid, ' "', 1, 1)-1) Planid--planid (100003624470" sflag=) intercept "before the string
Into V_packplanid
From (Select substr (content,instr (content, ' Packplanid ', 1, 1) + 11+1,20) Planid--packplanid= length is 11+1 (1), 20 characters are truncated backwards
From Sducy.cheyang
where t.oid = v_oid);

Test results:

Planid

100003624470

Oracle intercepts strings and lookup strings, and uses them together to intercept specific characters