Data manipulation

Data type

Boolean: Yes/No. Use to choose between 2 choices.

Currency: Use for the amount of money and with a currency symbols. For example, $350.

Text: Large amounts of alphanumeric data: sentences and paragraphs. For example, phone numbers are used in Text because some phone numbers use hyphens and possibly parentheses

Numeric: For numeric values such as 1, 2, 3 ....

Autonumber: type of data used in Microsoft Access tables to generate an automatically incremented numeric counter. It may be used to create an identity column which uniquely identifies each record of a table.

Date/time: Used to identify a certain date or time. For example, 13-Aug-2020. There are many types of dates, one of the example is dd-mm-yyyy (Medium Date)

Flat File VS Relational Database

Flat file Database

Primary Key & Foreign Key ALENNA ✅

Primary Key: A field in a database that is unique to a particular record. E.g. Book_ID

AdiVincent

DATA TYPE FOR PHONE NUMBER
TEXT

COMMON MISTAKES Demi

A flat file database is a database that stores data in a plain text file

Data type for telephone number - text because the 0 will go missing if you use numeric

Relational Database

The data is NOT stored in the same table

Contains two or more tables of data that are linked together by relationships

A flat file can be a plain text file, or a binary file.

Hayley's branch 🎉 🎉🎉 (do not touch) Data Verification - To check the data entered into system are identical to the data on the original source document.

Alphanumeric:It is a combination that consists of number and letters. Alphanumeric is a data type means that any numbers it contains is to be treated as just another character.


Alpha(bet) + Numeric(al)

Foreign Key: A regular field in one table which is being used as the key field in another table, sed to link tables together and create a relationship.

Iverson's

:

Importing data from csv file, dont forgert to change data type.

MS ACCESS FORM

Create dropdown menu

(format check) Beware of the format of Date e.g. dd/MM/yy or MM/dd/yy

  1. Click the textbox
  1. Right click > Change to > Combo Box

Please read the questions carefully! I know ICT is complex but I believe in you ;)

Demetra

Data Validation

  1. Show Table > Select Table Framework(Depends)

Common fields are needed in order to link two tables together (Primary Key to Foreign Key)

Method 2) Visual checking = Data is compared to what is on a form/document/card with what is typed in to check that both match

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  1. Field > Subject ID(Depends) and Field > Subject_Name > Sort > Ascending

Examples of Flat file Database Software: Microsoft Excel, Microsoft Access, FileMaker or FileMaker Pro, Berkeley DB, and Borland Reflex

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  1. Run > Close inside

Advantage of Flat File Database:


: :

Wild card search

Method 1) Double entry of data = data is entered twice; only if it matches is it accepted for processing. When you create a new password, you have to enter it twice to check you have not made a mistake.

  • repeated data is moved into its own table

Like criteria

Disadvantage of Flat File Database:

Data Redundancy

Space is wasted with duplicated data

Take time to enter the unnecessarily data

Benefit using Relational Database

Duplicated Data reduced

Data storage space not wasted

Quicker to enter data (less duplicate data)

Quicker to update data

Definition: A process performed by a computer when the data entered. To check whether the data satisfies certain criteria. Data is checked against the set of validation rules which you set when developing the database system

Presence Check

Range check

Type check

Length Check

Digit Check

Format check

Flat files are relatively quick and easy to set up and use

They are ideal for smaller databases.

They provide many of the sorting and searching tools commonly needed by users of the database..

a' (shift 8)- opening word starting with a e.g.Alenna

'a (shift 8)- ending word with the letter a e.g.Lovisa

Mathematical Criteria :)

like star'kite' star 'the symbol'-Whatever text you put inside there e.g'kite' (press shift 8)

More than or after >

Less than or Before <

More than or Equal to >=

Less than or Equal to <=

Logical Operators

Ur welcome sex

Between And - e.g. Between 2004 And 2020

Or - e.g. Febuary or August

Not- use to not include e.g.Not 33

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Query

Finding fields with no data

Null- Used to display fields wih no data

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Searching fields that contains a certain number of criteria

"?????"

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