SQL || SQL Interview Questions And Answers || EXAMPLES

. How to fetch common records from two tables?
Common records result set can be achieved by -.

1 Select studentID from student. strong INTERSECT /strongSelect StudentID from Exam

47. How to fetch alternate records from a table?
Records can be fetched for both Odd and Even row numbers -.
To display even numbers-.
MySQL

1 Select studentId from (Select rowno, studentId from student) where mod(rowno,2)=0

To display odd numbers-.
MySQL

1 Select studentId from (Select rowno, studentId from student) where mod(rowno,2)=1

from (Select rowno, studentId from student) where mod(rowno,2)=1.[/sql]
48. How to select unique records from a table?
Select unique records from a table by using DISTINCT keyword.

1 Select DISTINCT StudentID, StudentName from Student.

49. What is the command used to fetch first 5 characters of the string?
There are many ways to fetch first 5 characters of the string -.
MySQL

1 Select SUBSTRING(StudentName,1,5) as studentname from student
MySQL

1 Select RIGHT(Studentname,5) as studentname from student

50. Which operator is used in query for pattern matching?
LIKE operator is used for pattern matching, and it can be used as -.
1. % – Matches zero or more characters.
2. _(Underscore) – Matching exactly one character.
Example -.
MySQL

1 Select * from Student where studentname like ‘a%’

1 Select * from Student where studentname like ‘ami_’