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Sunday, December 6, 2009

Single Marks Questions of University Exam Msc(IT)-1st

[1]. What are the four primary properties that most SELECT statements describe in a result set?

Most SELECT statements describe the following four primary properties of a result set:

  • The columns to be included in the result set
  • The tables from which the result set data is retrieved
  • The conditions that the rows in the source table must meet to qualify for the result set
  • The ordering sequence of the rows in the result set

[2]. What are the main clauses of a SELECT statement?

The main clauses of a SELECT statement can be summarized as follows:

SELECT select_list

[INTO new_table_name]

FROM table_list

[WHERE search_conditions]

[GROUP BY group_by_list]

[HAVING search_conditions]

[ORDER BY order_list [ASC | DESC] ]

[3]. What are several keywords that you can use in a select list?

DISTINCT, TOP n, and AS

[4]. What type of objects can you specify in the FROM clause of a SELECT statement?

Tables, views, joins, and derived tables

[5]. What purpose does a join provide when used in a SELECT statement?

By using joins, you can retrieve data from two or more tables based on logical relationships between the tables. Joins indicate how SQL Server should use data from one table to select the rows in another table.

[6]. What are the differences between inner joins and outer joins?

Inner joins return rows only when there is at least one row from both tables that matches the join condition, eliminating the rows that do not match with a row from the other table. Outer joins, however, return all rows from at least one of the tables or views mentioned in the FROM clause (as long as these rows meet any WHERE or HAVING search conditions).

[7]. What is a subquery?

A subquery is a SELECT statement that returns a single value and is nested inside a SELECT, INSERT, UPDATE, or DELETE statement or inside another subquery. A subquery can be used anywhere an expression is allowed. A subquery is also called an inner query or inner select, while the statement containing a subquery is called an outer query or outer select.

[8]. What are the differences between a CUBE operator and a ROLLUP operator?

The ROLLUP operator generates a result set that is similar to the result sets generated by the CUBE operator. The differences between CUBE and ROLLUP are as follows:

  • CUBE generates a result set showing aggregates for all combinations of values in the selected columns.
  • ROLLUP generates a result set showing aggregates for a hierarchy of values in the selected columns.

[9]. For what types of columns can you not specify values in an INSERT statement?

Columns with an IDENTITY property, columns with a DEFAULT definition that uses the NEWID() function, and computed columns

[10]. What methods can you use to modify data in a SQL Server database?

The UPDATE statement, database APIs and cursors, and the UPDATETEXT statement

[11]. What are the major clauses contained in an UPDATE statement?

SET, WHERE, and FROM

[12]. Which statement should you use to delete all rows in a table without having the action logged?

The TRUNCATE TABLE statement

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