Database Literacy: Why use a database? (papercraft version)

Database Literacy: Why use a database? (papercraft version)

Information is what we know about something.

Data is raw information that can be manipulated by a computer.

So a Database is a structured collection of information.

Our database might start out really simple, like this spreadsheet showing cars and theirowners.

A field describes a single attribute of anobject.

A record is a set of fields that describesa single person or object.

If our customer Sally gets married and changesher name, duplicate records may be created.

How do we know which Sally is the real Sally?We can add a primary key field to uniquely identify Sally.

Unlike her last name, this identifier will never change.

However, we could still run into problems if Sally purchases a second car from us.

Duplicate data increases the potential for errors.

A relational database solves this problem by splitting different kinds of data intosets called tables.

One table is storing data about cars, whilethe other table is storing data about customers.

Keys are used to relate the data in the tables.

Primary keys uniquely identify records in a table…… while Foreign keys identify records in a different table.

Databases use different types of relationships.

This relationship between cars and customersis called a One to Many relationship.

Sally can own many cars, but each car canonly have one owner.

Notice how we have left over data that isnot being duplicated? This lack of duplication helps to ensure thatthe data is valid.

Luckily, the person using the database doesnot need to understand the structure of the database.

Instead, we can use a database form to allow us to only edit and see the data we are interestedin, and hide all of the complexity, handling it behind the scenes.

So while a database does add more complexity….

These structures and rules help keep datavalid, And database forms hide the complexity, managingdata for us behind the scenes.

This manipulative was created in MicrosoftExcel.

You can download this manipulative from my website and make your own copy.

Oncethe appropriate sheets are printed on cardstock, the individual data elements should be cutout.

Pieces of self-adhesive loop and hook fastener“hooks” can be applied on the back of each data element.

The spreadsheet and databasesheets are printed on both sides of a piece of cardstock, with pieces of self-adhesive“fuzzies” applied to the spaces where data belongs.

Finally, the database form sheet is printedon normal paper, with the spaces removed showing the data fields accessible underneath theform.

Due to the fuzzy side of the hook and loopfastener adhesives being used twice as frequently as the hook sides, assembling two dozen ofthese manipulatives used more than 15 feet of Velcro and an overabundance of hook pieceswere left over.

This tool and video is licensed for your freeuse under the Creative Commons Attribution – Non commercial – Share Alike license.

This means that you may use and distribute the tool freely for non-commercial use, suchas in your classroom, and you are welcome to make alterations to the tool, providedthat you attribute me AND distribute your alterations under the same license.

If you find it useful, make any alterations,or have any questions or comments, I would love to hear from you, so please drop me aline.

Source: Youtube