Which string function returns the index of the first occurrence of substring?

Solution (By Examveda Team)

This question asks about a MySQL function that helps us find the position of a smaller piece of text (a substring) within a larger piece of text (a string).
Let's break down the options:
Option A: INSERT() - This function is used for inserting new text into a string at a specific position. It doesn't help us find the position of a substring.
Option B: INSTR() - This function does exactly what we need! It returns the index (position) of the first occurrence of a substring within a string.
Option C: INSTRING() - This function doesn't exist in MySQL.
Option D: INFSTR() - This function doesn't exist in MySQL.
Therefore, the correct answer is Option B: INSTR().
Let's imagine we have a string "Hello, world!" and we want to find the position of the word "world". The function INSTR("Hello, world!", "world") would return 8, because "world" starts at the 8th position in the string.