Similar indexof usage InStr function __ static function in Oracle

There is no indexof () function in Oracle
but provides a InStr () method specific use:
Select InStr (' Baoding Nanshi District ', ' City ', 1,1)-1 from dual;
Explanation: 1. The ' Baoding Nanshi District ' => can be an expression, or it can be a specific data of
          2. ' City ' => is the symbol of separation, here is the word "city" in two sets of data
          3. The first 1 starts from the left and, if-1, starts on the right.
          4. The second 1 is the first occurrence of "city".


under GBK encoding, one Chinese occupies two bytes
select InStr (' Baoding Nanshi District ', ' City ', 1,1) from dual; The value is 5
Select InStr (' Baoding ', ' City ', Nanshi District ') from The value of dual is 9

select InStr (' Baoding Nanshi District ', ' City ', -1,1) from dual; The value is 9
Select InStr (' Baoding ', ' City ', -1,2) from Nanshi District; the value is 5