Class 12 Informatics Practices (065)
Sumita Arora Book Exercise Question Answer
Chapter 6 :- MySQL Functions Check Point
1. Which function can be used to concatenate two strings?
Answer: CONCAT()
2. Which function(s) can be used for extracting a substrings?
Answer: LEFT(), RIGHT(), SUBSTR(), MID().
LEFT() – extract substring having specified number of characters from left side of the string.
LEFT(string, number_of_chars)
mysql> SELECT LEFT(“anjeevsinghacademy.com”, 6)
anjeev
RIGHT() – extract substring having specified number of characters from right side of the string.
RIGHT(string, number_of_chars)
mysql> SELECT LEFT(“anjeevsinghacademy.com”, 11)
academy.com
SUBSTR() – extract substring having specified number of characters from the specified position from the string.
SUBSTR(string, position, number_chars)
number_chars is an optional, if not given, then it returns all characters (till last) as substring, from the specified position.
mysql> SELECT SUBSTR(“anjeevsinghacademy.com”, 7)
singhacademy.com
mysql> SELECT SUBSTR(“anjeevsinghacademy.com”, 7, 5)
singh
MID() – extract substring having specified number of characters from the specified position from the string.
MID(string, position, number_chars)
mysql> SELECT MID(“anjeevsinghacademy.com”, 7, 5)
singh
mysql> SELECT MID(“anjeevsinghacademy.com”, 7)
singhacademy.com
3. What is the difference between Trim() and Rtrim()?
Answer: Trim( ) function removes leading and trailing spaces from a given string, while Rtrim() function removes only trailing spaces from a given string.
mysql> SELECT CONCAT(“anjeev” , Trim(” singh “), “academy.com”))
anjeevsinghacademy.com
mysql> SELECT CONCAT(“anjeev” , Rtrim(” singh “), “academy.com”))
anjeev singhacademy.com
4. What is the difference between round() and truncate()?
Answer:
5.
