a2zinterviews

31.	what is difference between primary key and candidate key?
	Primary Key - are used to uniquely identify each row of the table. A table can have only one primary Key. Candidate Key - primary key is a candidate key. There is no difference. By common convention one candidate key is designated as a “primary” one and that key is used for any foreign key references.

32.	How do you get the month from a timestamp?
	SELECT MONTH(january_timestamp) from tablename;

33.	What do % and _ mean inside LIKE statement?
	% corresponds to 0 or more characters, _ is exactly one character.

34.	If you specify the data type as DECIMAL (5,2), what’s the range of values that can go in this table?
	999.99 to -99.99. Note that with the negative number the minus sign is considered one of the digits.

35.	How do you get the current date in Mysql?
	SELECT CURRENT_DATE();