Which of the following is not a valid aggregate function in MYSQL ?

1. COUNT()
2. SUM()
3. MAX()
4. LEN()

What will be printed by the given query ?

SELECT LENGTH("WINNER");

1. 7
2. 6
3. 8
4. 9

If the substring is not present in a string, the INSTR() returns:

1. -1
2. 1
3. NULL
4. 0

What will be returned by the given query ?

SELECT concat("It", "was", "ok");

1. "It was ok"
2. "It wasok"
3. "Itwasok"
4. "Itwas ok"