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Database Development For Dummies Torrent
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Lucille Minasian
Dec 27, 2023, 1:13:58 AM12/27/23
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The book acquaints you with the most popular data modeling methods and shows you how to systematically design and develop a system incorporating a database and one or more applications that operate on it. Here's more of what you'll discover in the book:
A properly designed database provides you with access to up-to-date, accurate information. Because a correct design is essential to achieving your goals in working with a database, investing the time required to learn the principles of good design makes sense. In the end, you are much more likely to end up with a database that meets your needs and can easily accommodate change.
Database Development For Dummies Torrent
Download https://t.co/fdzJJaq3ik
This article provides guidelines for planning a desktop database. You will learn how to decide what information you need, how to divide that information into the appropriate tables and columns, and how those tables relate to each other. You should read this article before you create your first desktop database.
Certain principles guide the database design process. The first principle is that duplicate information (also called redundant data) is bad, because it wastes space and increases the likelihood of errors and inconsistencies. The second principle is that the correctness and completeness of information is important. If your database contains incorrect information, any reports that pull information from the database will also contain incorrect information. As a result, any decisions you make that are based on those reports will then be misinformed.
Next, consider the types of reports or mailings you might want to produce from the database. For instance, you might want a product sales report to show sales by region, or an inventory summary report that shows product inventory levels. You might also want to generate form letters to send to customers that announces a sale event or offers a premium. Design the report in your mind, and imagine what it would look like. What information would you place on the report? List each item. Do the same for the form letter and for any other report you anticipate creating.
Think about the questions you might want the database to answer. For instance, how many sales of your featured product did you close last month? Where do your best customers live? Who is the supplier for your best-selling product? Anticipating these questions helps you zero in on additional items to record.
To divide the information into tables, choose the major entities, or subjects. For example, after finding and organizing information for a product sales database, the preliminary list might look like this:
When you design your database, always try to record each fact just once. If you find yourself repeating the same information in more than one place, such as the address for a particular supplier, place that information in a separate table.
You should also consider whether the database will hold information that is of domestic origin only, or international, as well. For instance, if you plan to store international addresses, it is better to have a Region column instead of State, because such a column can accommodate both domestic states and the regions of other countries/regions. Similarly, Postal Code makes more sense than Zip Code if you are going to store international addresses.
In most cases, you should not store the result of calculations in tables. Instead, you can have Access perform the calculations when you want to see the result. For example, suppose there is a Products On Order report that displays the subtotal of units on order for each category of product in the database. However, there is no Units On Order subtotal column in any table. Instead, the Products table includes a Units On Order column that stores the units on order for each product. Using that data, Access calculates the subtotal each time you print the report. The subtotal itself should not be stored in a table.
Each table should include a column or set of columns that uniquely identifies each row stored in the table. This is often a unique identification number, such as an employee ID number or a serial number. In database terminology, this information is called the primary key of the table. Access uses primary key fields to quickly associate data from multiple tables and bring the data together for you.
For the product sales database, you can create an AutoNumber column for each of the tables to serve as primary key: ProductID for the Products table, OrderID for the Orders table, CustomerID for the Customers table, and SupplierID for the Suppliers table.
Access is a relational database management system. In a relational database, you divide your information into separate, subject-based tables. You then use table relationships to bring the information together as needed.
Consider this example: the Suppliers and Products tables in the product orders database. A supplier can supply any number of products. It follows that for any supplier represented in the Suppliers table, there can be many products represented in the Products table. The relationship between the Suppliers table and the Products table is, therefore, a one-to-many relationship.
To represent a one-to-many relationship in your database design, take the primary key on the "one" side of the relationship and add it as an additional column or columns to the table on the "many" side of the relationship. In this case, for example, you add the Supplier ID column from the Suppliers table to the Products table. Access can then use the supplier ID number in the Products table to locate the correct supplier for each product.
In the product sales database, the Orders table and the Products table are not related to each other directly. Instead, they are related indirectly through the Order Details table. The many-to-many relationship between orders and products is represented in the database by using two one-to-many relationships:
See if you can use the database to get the answers you want. Create rough drafts of your forms and reports and see if they show the data you expect. Look for unnecessary duplication of data and, when you find any, alter your design to eliminate it.
Suppose that each product in the product sales database falls under a general category, such as beverages, condiments, or seafood. The Products table could include a field that shows the category of each product.
A better solution is to make Categories a new subject for the database to track, with its own table and its own primary key. You can then add the primary key from the Categories table to the Products table as a foreign key.
You can apply the data normalization rules (sometimes just called normalization rules) as the next step in your design. You use these rules to see if your tables are structured correctly. The process of applying the rules to your database design is called normalizing the database, or just normalization.
2. How have others solved this design-time vs. runtime data problem? In my case, i cannot very easily use the same data for both (as one would be able to with, say, a database query).
In Part I, I give you the background information you need in order to build high-quality databases and database applications. I describe the different classes of databases and what makes them different. I also describe the critical role that databases play in our data-saturated world, including the so-called new economy. I offer a brief history of data processing and the advent of database systems, leading up to coverage of what databases and database applications are, followed by a structured approach to building them. I also describe some of the major pitfalls of database development, and explain how to avoid them.
Database processing is one of the more common operations performed on computers today. In fact, only word-processing and spreadsheet packages outrank database management systems among the most popular business tools. Everyone, from the largest corporate entities to private individuals, wants to keep track of something. Applications such as order entry, accounts receivable, accounts payable, and general ledger all incorporate databases. Companies keep track of their customers, product inventories, employees, and capital assets in databases. Businesses, governments, and organizations around the world would grind to a halt without databases.
Large international corporations and national governments have substantially different data management needs from those of a private individual or even a small to medium-sized company. Large database users have demanding capacity and performance requirements and are willing to pay what it takes to meet those requirements. That kind of power would be serious overkill for an individual, local non-profit organization, or small business, and would be too expensive anyway. As a result, different database development tools are available for addressing different market segments. Some of these tools, called database management systems (DBMSs), are capable of supporting huge, high-performance databases, but require very powerful (and expensive) mainframe computers to do the job. Other tools run on personal computers, and are limited in the size and performance of databases they are able to support.
As computer power has steadily increased and become less expensive, enterprise class databases have become even more powerful and are capable of supporting much larger collections of data. The data on such systems is also accessible to thousands of simultaneous users. Today, large organizations get orders of magnitude larger and faster databases for much lower cost than was true in the early days of database, but costs of such systems are still out of reach for individual users. This is not a big problem, because few individuals need a database system that supports thousands of simultaneous users.
In 1975, the first, primitive personal computer kits arrived on the scene, and in 1976 you could buy one already assembled. (Pretty slick, eh?) These machines were not powerful enough to support even a very cut-down database management system, but performance improved steadily. With the advent of the IBM PC coupled with hard disk storage, database technology started to proliferate on personal computers in 1981.
0aad45d008
A properly designed database provides you with access to up-to-date, accurate information. Because a correct design is essential to achieving your goals in working with a database, investing the time required to learn the principles of good design makes sense. In the end, you are much more likely to end up with a database that meets your needs and can easily accommodate change.
Database Development For Dummies Torrent
Download https://t.co/fdzJJaq3ik
This article provides guidelines for planning a desktop database. You will learn how to decide what information you need, how to divide that information into the appropriate tables and columns, and how those tables relate to each other. You should read this article before you create your first desktop database.
Certain principles guide the database design process. The first principle is that duplicate information (also called redundant data) is bad, because it wastes space and increases the likelihood of errors and inconsistencies. The second principle is that the correctness and completeness of information is important. If your database contains incorrect information, any reports that pull information from the database will also contain incorrect information. As a result, any decisions you make that are based on those reports will then be misinformed.
Next, consider the types of reports or mailings you might want to produce from the database. For instance, you might want a product sales report to show sales by region, or an inventory summary report that shows product inventory levels. You might also want to generate form letters to send to customers that announces a sale event or offers a premium. Design the report in your mind, and imagine what it would look like. What information would you place on the report? List each item. Do the same for the form letter and for any other report you anticipate creating.
Think about the questions you might want the database to answer. For instance, how many sales of your featured product did you close last month? Where do your best customers live? Who is the supplier for your best-selling product? Anticipating these questions helps you zero in on additional items to record.
To divide the information into tables, choose the major entities, or subjects. For example, after finding and organizing information for a product sales database, the preliminary list might look like this:
When you design your database, always try to record each fact just once. If you find yourself repeating the same information in more than one place, such as the address for a particular supplier, place that information in a separate table.
You should also consider whether the database will hold information that is of domestic origin only, or international, as well. For instance, if you plan to store international addresses, it is better to have a Region column instead of State, because such a column can accommodate both domestic states and the regions of other countries/regions. Similarly, Postal Code makes more sense than Zip Code if you are going to store international addresses.
In most cases, you should not store the result of calculations in tables. Instead, you can have Access perform the calculations when you want to see the result. For example, suppose there is a Products On Order report that displays the subtotal of units on order for each category of product in the database. However, there is no Units On Order subtotal column in any table. Instead, the Products table includes a Units On Order column that stores the units on order for each product. Using that data, Access calculates the subtotal each time you print the report. The subtotal itself should not be stored in a table.
Each table should include a column or set of columns that uniquely identifies each row stored in the table. This is often a unique identification number, such as an employee ID number or a serial number. In database terminology, this information is called the primary key of the table. Access uses primary key fields to quickly associate data from multiple tables and bring the data together for you.
For the product sales database, you can create an AutoNumber column for each of the tables to serve as primary key: ProductID for the Products table, OrderID for the Orders table, CustomerID for the Customers table, and SupplierID for the Suppliers table.
Access is a relational database management system. In a relational database, you divide your information into separate, subject-based tables. You then use table relationships to bring the information together as needed.
Consider this example: the Suppliers and Products tables in the product orders database. A supplier can supply any number of products. It follows that for any supplier represented in the Suppliers table, there can be many products represented in the Products table. The relationship between the Suppliers table and the Products table is, therefore, a one-to-many relationship.
To represent a one-to-many relationship in your database design, take the primary key on the "one" side of the relationship and add it as an additional column or columns to the table on the "many" side of the relationship. In this case, for example, you add the Supplier ID column from the Suppliers table to the Products table. Access can then use the supplier ID number in the Products table to locate the correct supplier for each product.
In the product sales database, the Orders table and the Products table are not related to each other directly. Instead, they are related indirectly through the Order Details table. The many-to-many relationship between orders and products is represented in the database by using two one-to-many relationships:
See if you can use the database to get the answers you want. Create rough drafts of your forms and reports and see if they show the data you expect. Look for unnecessary duplication of data and, when you find any, alter your design to eliminate it.
Suppose that each product in the product sales database falls under a general category, such as beverages, condiments, or seafood. The Products table could include a field that shows the category of each product.
A better solution is to make Categories a new subject for the database to track, with its own table and its own primary key. You can then add the primary key from the Categories table to the Products table as a foreign key.
You can apply the data normalization rules (sometimes just called normalization rules) as the next step in your design. You use these rules to see if your tables are structured correctly. The process of applying the rules to your database design is called normalizing the database, or just normalization.
2. How have others solved this design-time vs. runtime data problem? In my case, i cannot very easily use the same data for both (as one would be able to with, say, a database query).
In Part I, I give you the background information you need in order to build high-quality databases and database applications. I describe the different classes of databases and what makes them different. I also describe the critical role that databases play in our data-saturated world, including the so-called new economy. I offer a brief history of data processing and the advent of database systems, leading up to coverage of what databases and database applications are, followed by a structured approach to building them. I also describe some of the major pitfalls of database development, and explain how to avoid them.
Database processing is one of the more common operations performed on computers today. In fact, only word-processing and spreadsheet packages outrank database management systems among the most popular business tools. Everyone, from the largest corporate entities to private individuals, wants to keep track of something. Applications such as order entry, accounts receivable, accounts payable, and general ledger all incorporate databases. Companies keep track of their customers, product inventories, employees, and capital assets in databases. Businesses, governments, and organizations around the world would grind to a halt without databases.
Large international corporations and national governments have substantially different data management needs from those of a private individual or even a small to medium-sized company. Large database users have demanding capacity and performance requirements and are willing to pay what it takes to meet those requirements. That kind of power would be serious overkill for an individual, local non-profit organization, or small business, and would be too expensive anyway. As a result, different database development tools are available for addressing different market segments. Some of these tools, called database management systems (DBMSs), are capable of supporting huge, high-performance databases, but require very powerful (and expensive) mainframe computers to do the job. Other tools run on personal computers, and are limited in the size and performance of databases they are able to support.
As computer power has steadily increased and become less expensive, enterprise class databases have become even more powerful and are capable of supporting much larger collections of data. The data on such systems is also accessible to thousands of simultaneous users. Today, large organizations get orders of magnitude larger and faster databases for much lower cost than was true in the early days of database, but costs of such systems are still out of reach for individual users. This is not a big problem, because few individuals need a database system that supports thousands of simultaneous users.
In 1975, the first, primitive personal computer kits arrived on the scene, and in 1976 you could buy one already assembled. (Pretty slick, eh?) These machines were not powerful enough to support even a very cut-down database management system, but performance improved steadily. With the advent of the IBM PC coupled with hard disk storage, database technology started to proliferate on personal computers in 1981.
0aad45d008
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