ER diagram basic

E-R diagram can express the overall logical structure of a database graphically. E-R diagrams are simple and clear—qualities that may well account in large part for the widespread use of the E-R model. Such a diagram consists of the following major components :-

• Rectangles, which represent entity sets
• Ellipses, which represent attributes
• Diamonds, which represent relationship sets
• Lines, which link attributes to entity sets and entity sets to relationship sets
• Double ellipses, which represent multivalued attributes
• Dashed ellipses, which denote derived attributes
• Double lines, which indicate total participation of an entity in a relationship set
• Double rectangles, which represent weak entity sets
Consider the entity-relationship diagram in Figure 2.8, which consists of two entity sets, customer and loan, related through a binary relationship set borrower. The attributes associated with customer are customer-id, customer-name, customer-street, and customer-city. The attributes associated with loan are loan-number and amount. In Figure 2.8, attributes of an entity set that are members of the primary key are underlined.
The relationship set borrower may be many-to-many, one-to-many, many-to-one, or one-to-one. To distinguish among these types, we draw either a directed line (→) or an undirected line (—) between the relationship set and the entity set in question.
• A directed line from the relationship set borrower to the entity set loan specifies that borrower is either a one-to-one or many-to-one relationship set, from customer to loan; borrower cannot be a many-to-many or a one-to-many relationship set from customer to loan.
• An undirected line from the relationship set borrower to the entity set loan specifies that borrower is either a many-to-many or one-to-many relationship set from customer to loan.

E-R diagram can express the overall logical structure of a database graphically. E-R diagrams are simple and clear—qualities that may well account in large part for the widespread use of the E-R model. Such a diagram consists of the following major components :-

• Rectangles, which represent entity sets
• Ellipses, which represent attributes
• Diamonds, which represent relationship sets
• Lines, which link attributes to entity sets and entity sets to relationship sets
• Double ellipses, which represent multivalued attributes
• Dashed ellipses, which denote derived attributes
• Double lines, which indicate total participation of an entity in a relationship set
• Double rectangles, which represent weak entity sets
Consider the entity-relationship diagram in Figure 2.8, which consists of two entity sets, customer and loan, related through a binary relationship set borrower. The attributes associated with customer are customer-id, customer-name, customer-street, and customer-city. The attributes associated with loan are loan-number and amount. In Figure 2.8, attributes of an entity set that are members of the primary key are underlined.
The relationship set borrower may be many-to-many, one-to-many, many-to-one, or one-to-one. To distinguish among these types, we draw either a directed line (→) or an undirected line (—) between the relationship set and the entity set in question.
• A directed line from the relationship set borrower to the entity set loan specifies that borrower is either a one-to-one or many-to-one relationship set, from customer to loan; borrower cannot be a many-to-many or a one-to-many relationship set from customer to loan.
• An undirected line from the relationship set borrower to the entity set loan specifies that borrower is either a many-to-many or one-to-many relationship set from customer to loan.

presentation introduction

                                   presentation

                                   introduction 

power point is a presentation and graphics package that enables you to present ideas on proposal in a highly propositional way,using a variety of formats-on screen,via overheads, white boards, etcetera,or in printed format

              screen layout

title bar: * identifies the application and the name of your current presentation

menu bar : * pull down menus list the commands and option available

standard toolbar : * provide buttons for the most frequently used options
 formatting toolbar : * contains buttons to change the look of the document text
available toolbar  : * many toolbars are available click the right mouse button in toolbar to see a list more than to other areas on your page by clicking and dragging

 insurrection point : * Usually a flashing I cursor shows where the next character will appear

 document window : * main making Area on the screen

 the ruler : * for changing margins, tabs and indents on documents and tables

 status bar : * area at the bottom of the PowerPoint screen gives detail of slide number and design template. it also provides details on the background activities of automatic document saving and printing

scroll bar : * horizontal and vertical bars used for scrolling through a document

other useful terms and explanation
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drag and drop :
* a way of moving small amounts of text in a document
• select text, hold down the left mouse button and drag to a new destination
• to take a copy - hold down the [ctrl] key while tragging

spell check :
* PowerPoint automatically check the spelling as you type either
• if a word  has a jagged red underline,click the right mouse button
° this will give a list of alternative spelling or the option to  a add to the dictionary
• click the left mouse button to select the required option
                         or
used spelling and grammar button of the standard toolbar to spell check the whole document

 zoom :
 * a way of changing the page magnification
• click the [zoom] button on the [standard] toolbar (it look like a white box with percentage in it)
                        or
• from the menu bar,select [view] [zoom]