Languages-Java [3i Infotech Placement]: Sample Questions 3 - 4 of 141

Glide to success with Doorsteptutor material for competitive exams : get questions, notes, tests, video lectures and more- for all subjects of your exam.

Question 3

Question

MCQ▾

Without the use of Cartesian product, how many joining conditions are required to join tables?

Choices

Choice (4)

a.

1

b.

3

c.

4

d.

2

Answer

b.

Explanation

  • To join ‘n’ tables ‘n-1’ conditions should be satisfied so to join tables conditions should be satisfied.
  • Join is used to collate data from two more tables- joined to appear as single table of data.
  • Combines columns from two or more tables by using values common to both table.
  • “Join” keyword is used in SQL queries for joining two or more tables.
  • Minimum required condition for joining table is (n-1) where n, is number of tables.
  • A table can also join to itself, which is known as self join.

Question 4

Edit

Describe in Detail

Essay▾

What is lightweight component?

Explanation

Understanding of Lightweight Components
  • Swing components depend less on the target platform and use less of the native GUI resource.
  • The swing components that do not rely on native GUI are referred to as lightweight components- no native screen resource of their own, so ‘lighter’ .
  • Lightweight components rely on the screen resource from an ancestor in the containment hierarchy, possibly the underlying frame object.
  • They subclass java. awt. component directly implementing the look and feel of the component in java.
  • They efficiently utilize system resource, can be transparent and not be rectangular.
  • LightweightPanel class that subclasses Container can also be used.

Developed by: