Frequently asked basic and advanced Top 80 + SQL Queries Interview Questions and Answers with Examples for Business Analyst, Data Analyst, DBA, Freshers and Experienced Java, PHP, Dot Net programmers in Oracle, MySQL and MS SQL Database.
Are you an Experienced Programmer or Database Administrator ? If so, visit our Interview Questions on Advanced and Complex SQL Query section of this article. For each question, if the SQL Commands differ for Oracle, MySQL and SQL Server Databases, specific queries with respect to a database is provided. If the answers are same for all databases, only one query is specified. Interview Questions on SQL are based on following two tables, Employee Table and Employee Incentive Table.
|1||John||Abraham||1000000||01-JAN-13 12.00.00 AM||Banking|
|2||Michael||Clarke||800000||01-JAN-13 12.00.00 AM||Insurance|
|3||Roy||Thomas||700000||01-FEB-13 12.00.00 AM||Banking|
|4||Tom||Jose||600000||01-FEB-13 12.00.00 AM||Insurance|
|5||Jerry||Pinto||650000||01-FEB-13 12.00.00 AM||Insurance|
|6||Philip||Mathew||750000||01-JAN-13 12.00.00 AM||Services|
|7||TestName1||123||650000||01-JAN-13 12.00.00 AM||Services|
|8||TestName2||Lname%||600000||01-FEB-13 12.00.00 AM||Insurance|
SQL Queries Interview Questions and Answers on "SQL Select"
Select * from employee
Select first_name, Last_Name from employee
Select first_name Employee Name from employee
Select upper(FIRST_NAME) from EMPLOYEE
Select lower(FIRST_NAME) from EMPLOYEE
select distinct DEPARTMENT from EMPLOYEE
Don't Miss - SQL and Database theory Interview Questions
7. Select first 3 characters of FIRST_NAME from EMPLOYEE
Oracle Equivalent of SQL Server SUBSTRING is SUBSTR, Query : select substr(FIRST_NAME,0,3) from employee
SQL Server Equivalent of Oracle SUBSTR is SUBSTRING, Query : select substring(FIRST_NAME,0,3) from employee
MySQL Server Equivalent of Oracle SUBSTR is SUBSTRING. In MySQL start position is 1, Query : select substring(FIRST_NAME,1,3) from employee
8. Get position of 'o' in name 'John' from employee table
Oracle Equivalent of SQL Server CHARINDEX is INSTR, Query : Select instr(FIRST_NAME,'o') from employee where first_name='John'
SQL Server Equivalent of Oracle INSTR is CHARINDEX, Query: Select CHARINDEX('o',FIRST_NAME,0) from employee where first_name='John'
MySQL Server Equivalent of Oracle INSTR is LOCATE, Query: Select LOCATE('o',FIRST_NAME) from employee where first_name='John'
9. Get FIRST_NAME from employee table after removing white spaces from right side
select RTRIM(FIRST_NAME) from employee
10. Get FIRST_NAME from employee table after removing white spaces from left side
select LTRIM(FIRST_NAME) from employee
11. Get length of FIRST_NAME from employee table
Oracle,MYSQL Equivalent of SQL Server Len is Length , Query :select length(FIRST_NAME) from employee
SQL Server Equivalent of Oracle,MYSQL Length is Len, Query :select len(FIRST_NAME) from employee
12. Get First_Name from employee table after replacing 'o' with '$'
select REPLACE(FIRST_NAME,'o','$') from employee
13. Get First_Name and Last_Name as single column from employee table separated by a '_'
Oracle Equivalent of MySQL concat is '||', Query : Select FIRST_NAME|| '_' ||LAST_NAME from EMPLOYEE
SQL Server Equivalent of MySQL concat is '+', Query : Select FIRST_NAME + '_' +LAST_NAME from EMPLOYEE
MySQL Equivalent of Oracle '||' is concat, Query : Select concat(FIRST_NAME,'_',LAST_NAME) from EMPLOYEE
14. Get FIRST_NAME ,Joining year,Joining Month and Joining Date from employee table
SQL Queries in Oracle, Select FIRST_NAME, to_char(joining_date,'YYYY') JoinYear , to_char(joining_date,'Mon'), to_char(joining_date,'dd') from EMPLOYEE
SQL Queries in SQL Server, select SUBSTRING (convert(varchar,joining_date,103),7,4) , SUBSTRING (convert(varchar,joining_date,100),1,3) , SUBSTRING (convert(varchar,joining_date,100),5,2) from EMPLOYEE
SQL Queries in MySQL, select year(joining_date),month(joining_date), DAY(joining_date) from EMPLOYEE