Mar. 07, 2024
Furniture
Tables are essential objects in a database because they hold all the information or data. For example, a database for a business can have a Contacts table that stores the names of their suppliers, e-mail addresses, and telephone numbers. Because other database objects depend so heavily on tables, you should always start your design of a database by creating all of its tables and then creating any other objects. Before you create tables in Access, consider your requirements and determine all the tables that you might need. For an introduction to planning and designing a database, see Database design basics.
A relational database like Access usually has several related tables. In a well-designed database, each table stores data about a particular subject, such as employees or products. A table has records (rows) and fields (columns). Fields have different types of data, such as text, numbers, dates, and hyperlinks.
A record: Contains specific data, like information about a particular employee or a product.
A field: Contains data about one aspect of the table subject, such as first name or e-mail address.
A field value: Each record has a field value. For example, Contoso, Ltd. or someone@example.com.
Top of Page
Tables and fields also have properties that you can set to control their characteristics or behavior.
1. Table properties
2. Field properties
In an Access database, table properties are attributes of a table that affect the appearance or behavior of the table as a whole. Table properties are set in the table's property sheet, in Design view. For example, you can set a table's Default View property to specify how the table is displayed by default.
A field property applies to a particular field in a table and defines one of the field's characteristics or an aspect of the field's behavior. You can set some field properties in Datasheet view. You can also set any field property in Design view by using the Field Properties pane.
Every field has a data type. A field's data type indicates the kind of data that the field stores, such as large amounts of text or attached files.
A data type is a field property, but it differs from other field properties as follows:
You set a field's data type in the table design grid, not in the Field Properties pane.
A field's data type determines what other properties the field has.
You must set a field's data type when you create the field.
You can create a new field in Access by entering data in a new column in Datasheet view. When you create a field by entering data in Datasheet view, Access automatically assigns a data type for the field, based on the value that you enter. If no other data type is implied by your input, Access sets the data type to Text. If needed, you can change the data type by using the Ribbon.
Examples of automatic data type detection
The following table shows how automatic data type detection works in Datasheet view.
If you enter:
Access creates a field with a data type of:
John
Short Text
http://www.contoso.com
You can use any valid Internet protocol prefix. For example, http://, https://, and mailto: are valid prefixes.
Hyperlink
1
Number, Long Integer
50,000
Number, Long Integer
50,000.99
Number, Double
50000.389
Number, Double
12/67
The date and time formats recognized are those of your user locale.
Date/Time
December 31, 2016
Date/Time
10:50:23
Date/Time
10:50 am
Date/Time
17:50
Date/Time
$12.50
The currency symbol recognized is that of your user locale.
Currency
21.75
Number, Double
123.00%
Number, Double
3.46E+03
Number, Double
Top of Page
Although each table stores data about a different subject, tables in an Access database usually store data about subjects that are related to each other. For example, a database might contain:
A customers table that lists your company’s customers and their addresses.
A products table that lists the products that you sell, including prices and pictures for each item.
An orders table that tracks customer orders.
Because you store data about different subjects in separate tables, you need some way to tie the data together so that you can easily combine related data from those separate tables. To connect the data stored in different tables, you create relationships. A relationship is a logical connection between two tables that specifies fields that the tables have in common. For more information, see Guide to table relationships.
Top of Page
Fields that are part of a table relationship are called keys. A key usually consists of one field, but may consist of more than one field. There are two kinds of keys:
Primary key A table can have only one primary key. A primary key consists of one or more fields that uniquely identify each record that you store in the table. Often, there is a unique identification number, such as an ID number, a serial number, or a code, that serves as a primary key. For example, you might have a Customers table where each customer has a unique customer ID number. The customer ID field is the primary key of the Customers table. When a primary key contains more than one field, it is usually composed of pre-existing fields that, taken together, provide unique values. For example, you might use a combination of last name, first name, and birth date as the primary key for a table about people. For more information, see adding or changing a table’s primary key.
Foreign key A table can also have one or more foreign keys. A foreign key contains values that correspond to values in the primary key of another table. For example, you might have an Orders table in which each order has a customer ID number that corresponds to a record in a Customers table. The customer ID field is a foreign key of the Orders table.
The correspondence of values between key fields forms the basis of a table relationship. You use a table relationship to combine data from related tables. For example, suppose that you have a Customers table and an Orders table. In your Customers table, each record is identified by the primary key field, ID.
To associate each order with a customer, you add a foreign key field to the Orders table that corresponds to the ID field of the Customers table, and then create a relationship between the two keys. When you add a record to the Orders table, you use a value for customer ID that comes from the Customers table. Whenever you want to view any information about an order's customer, you use the relationship to identify which data from the Customers table corresponds to which records in the Orders table.
1. A primary key, identified by the key icon next to the field name.
2. A foreign key — note the absence of the key icon.
Do not add a field if you expect that each unique entity represented in the table might require more than value for the field. Continuing the preceding example, if you want to start tracking orders placed by your customers, you do not add a field to the table, because each customer will have more than one order. Instead, you create a new table to store orders, and then create a relationship between the two tables.
Top of Page
Keeping data separated in related tables produces the following benefits:
Consistency Because each item of data is recorded only once, in one table, there is less opportunity for ambiguity or inconsistency. For example, you store a customer's name only once, in a table about customers, rather than storing it repeatedly (and potentially inconsistently) in a table that contains order data.
Efficiency Recording data in only one place means you use less disk space. Moreover, smaller tables tend to provide data more quickly than larger tables. Finally, if you don't use separate tables for separate subjects, you will introduce null values (the absence of data) and redundancy into your tables, both of which can waste space and impede performance.
Comprehensibility The design of a database is easier to understand if the subjects are properly separated into tables.
Plan your tables with relationships in mind. You can use the Lookup Wizard to create a foreign key field if the table that contains the corresponding primary key already exists. The Lookup Wizard creates the relationship for you. For more information, see Create or delete a lookup field.
Top of Page
Create a table and add fields
Antique drafting tables can be considered a workhorse of historical workplace furniture, and their huge sizes make them a vital tool for all of the artists, designers, and creatives around the world. These large pieces are testament to the beautiful design and painstaking craftsmanship of the 19th and 20th century and can be both a practical and fun way to bring a dash of history into your home.
Typically, a fixture in an 18th or 19th century gentleman's office or study, drafting tables featured an adjustable surface to facilitate detailed drawing. Often, this surface could be raised or lowered and could be tipped at a variety of angles. Generally, an architect or artist would use the table while standing, but sometimes, a tall stool could provide more comfortable working conditions. Some tables also featured a mechanism to adjust the height, so they could be used in a seated position.
Related ArticlesEarly drafting tables were constructed out of oak or other sturdy hardwoods. In addition to fulfilling a practical function for the artist or drafter, they were just as thoughtfully designed to be aesthetic pieces of furniture as the items their owners created. These tables were heavy, but they were finely crafted and somewhat difficult to adjust. Fully wooden tables typically used a series of notches and an A-frame to move their tabletops up and down, while those with cast-iron frames could use a flywheel system to slowly pull and push the tabletops into place.
In the early 20th century, drafting tables were redesigned to be lighter and more portable. They were important fixtures in many architecture and engineering firms, and their physical appearance became more utilitarian. Instead of fine woods and metal, the tables were now constructed of plastic, vinyl, and steel. The design of the tables became more complex, and many featured integrated drafting tools.
As computer-aided drafting became the standard practice in the late 20th century, drafting tables began to disappear from use in many firms. Some artists, architects, and engineers who are more comfortable with traditional pencil design still use drafting tables to do initial sketches or edit and revise computer-created drawings. However, drafting tables are now a much more niche product, as not as many jobs require the adjustments to their desks that drafting tables allow.
As with most antique and vintage furniture, drafting tables from the 19th and 20th century are really easy to use in a 21st century context. In the same way that a writer might employ an 18th century writing desk, an artist or architect can put an antique drafting table to use in their personal and professional work. Of course, different styles suit different people, and these are some of the most popular drafting table styles found on the market today.
Many of the drafting tables made at the very start of the 20th century were made entirely out of wood and used an interesting notched A-frame adjustment mechanism to shift their table tops back and forth. Yet, as industrial manufacturing and materials became cheaper and design influenced by this sleek, industrial style, drafting tables started having more metal incorporated into their shapes. Their legs and adjustment mechanisms began being cast out of iron and steel, making them both heavier and sturdier than their wooden counterparts.
As Art Deco design started shifting away from the sanitized industrial characteristics of the 1930s into a softer, warmer aesthetic in the 1940s, drafting tables were redesigned to reflect an overall warmer, yet functional, style. Drafting tables from these middle decades bear a strong resemblance to the school desks from this period, with their basic light-colored wooden tops and simple metal legs.
Interestingly, as Mid-Century Modernism took over, these drafting tables took a shift back towards a fully (or seemingly fully) wooden design. However, they didn't forgo the advancements in technology and change the more efficient mechanism to rotate the tables with.
As most antique collectors know, old items can often be used in new ways. Even if you won't be using an antique architect's table to design your next home addition, you can find some fun ways to give new life to this beautiful piece of furniture. Here are a few ideas:
At garage sales, estate sales, and thrift stores, you might be able to get away with an antique drafting table for an impressively low price. Yet, with online retailers, you're more so at the mercy of who's selling them. But, if you find yourself looking for these tables online, here are a few places to start:
Antique drafting tables are perfect for people constantly running out of space on their work stations; their overly large tabletops are just waiting to be filled with your favorite knickknacks and newest creative endeavors. Let your imagination run wild with these special pieces of historic furniture.
If you are interested in sending in a Guest Blogger Submission,welcome to write for us!
All Comments ( 0 )