TechGeek-GenZ

  1. What is COALESCE in SQL Server? COALESCE is used to return first non-null expression within the arguments. This function is used to return a non-null from more than one column in the arguments. Example –  Select COALESCE(empno, empname, salary) from employee; 2. Can we check locks in database? If so, how can we do this lock check? Yes, we can check locks in the database. It can be achieved by using in-built stored procedure called sp_lock. 3. What will be the maximum number of index per table? 1000 Index can be used as maximum number per table. 1 Clustered Index and 999 Non-clustered indexes per table can be used in SQL Server. 4. How data can be copied from one table to another table? INSERT INTO SELECT This command is used to insert data into a table which is already created. SELECT INTO This command is used to create a new table and its structure and data can be copied from existing table. 5. What is Query to find Second highest salary for employee? This is mos...

  Test yourself with  real  SQL interview questions: Question 1 Given the table below, write a SQL query that retrieves the personal data about alumni who scored above 16 on their calculus exam. alumni student_id name surname birth_date faculty 344 Aishani Lopes 1990-04-26 Med School 345 Robert Roy 1990-03-09 Physics evaluate student_id class_id exam_date grade 344 74 2014-06-19 17 344 87 2014-06-06 20 345 74 2014-06-19 11 curriculum class_id class_name professor_id semester 74 algebra 430 2014_summer 87 calculus 531 2014_summer 46 statistics 626 2014_winter There can be different answers. This is one of them. SELECT a . name , a . surname , a . birth_date , a . faculty FROM alumni AS a INNER JOIN evaluate AS e ON a . student_id = e . student_id INNER JOIN curriculum AS c ON e . class_id = c . class_id WHERE c . class_name = 'calculus' AND e . grade > 16 ; Question 2 There is a beverages  table.  id na...