SQL

21. What is PRIMARY KEY? A PRIMARY KEY constraint is a unique identifier for a row within a database table. Every table should have a primary key constraint to uniquely …

11. What is SQL Profiler? SQL Profiler is a graphical tool that allows system administrators to monitor events in an instance of Microsoft SQL Server. You can capture and save …

1. Which TCP/IP port does SQL Server run on? How can it be changed? SQL Server runs on port 1433. It can be changed from the Network Utility TCP/IP properties. …

10. What is Index? An index is a physical structure containing pointers to the data. Indices are created in an existing table to locate rows more quickly and efficiently. It …

1. What is RDBMS? Relational Data Base Management Systems (RDBMS) are database management systems that maintain data records and indices in tables. Relationships may be created and maintained across and …

41.Say True or False. Give explanation if False. INSERT statement does not allow copying rows from one table to another. False. INSERT statement allows to add rows to a table …

31.What do you understand by a subquery? When is it used? A subquery is a SELECT statement embedded in a clause of another SELECT statement. It is used when the …

21.What is the difference between cross joins and natural joins? The cross join produces the cross product or Cartesian product of two tables. The natural join is based on all …

11.What is the default ordering of data using the ORDER BY clause? How could it be changed? The default sorting order is ascending. It can be changed using the DESC …

1.What is the difference between SQL and MySQL or SQL Server? SQL or Structured Query Language is a language; language that communicates with a relational database thus providing ways of …