{"id":1654,"date":"2022-06-03T14:30:15","date_gmt":"2022-06-03T14:30:15","guid":{"rendered":"https:\/\/visitgis.com\/?p=1654"},"modified":"2022-06-03T14:46:46","modified_gmt":"2022-06-03T14:46:46","slug":"frequently-asked-sql-interview-questions-and-answers","status":"publish","type":"post","link":"https:\/\/visitgis.com\/frequently-asked-sql-interview-questions-and-answers\/","title":{"rendered":"The Best most Frequently Asked SQL Interview Questions and Answers"},"content":{"rendered":"\n

I know you are looking for such an important question to crack upcoming interview. So, without wasting time. We move towards SQL<\/a> interview questions and answers.<\/p>\n\n\n\n

What is the difference between \u2018HAVING\u2019 CLAUSE and a \u2018WHERE\u2019 CLAUSE?<\/strong><\/h2>\n\n\n\n

HAVING clause use only with SELECT statement. It is usually used in a GROUP BY clause and whenever GROUP BY is not used, HAVING behaves like a WHERE clause. Having clause is use with the GROUP BY function. But, Where as clause applies to each row before they are a part of GROUP BY function.<\/p>\n\n\n\n

What are the various levels of constraints?<\/strong><\/h2>\n\n\n\n

Constraints are the physical and logical address of a column. It entitles data uniqueness. There are two levels  of a constraint:<\/p>\n\n\n\n