File Processing with Excel’s List

File Concepts File consists of a group of records. Each record contains a group of fields. Example: Student file SID Sname Major Sex GPA S1 Peter CIS M 3.0 S3 Paul ACCT M 2.7 S5 Mary CIS F 3.2

Excel’s List An Excel list consists of columns and rows of data structured in a specific way: Each column contains the same category of data in every row in the column(similar to a field in a file) Each row in the list contains all of the fields of data for one entity (a person,organization, object, etc.) similar to a record in a file. The first row of the list must contain a unique name at the top of each column. There can be no blank rows in the list (there can be blank cells in a column, but the entire row cannot be empty)

List Example

Key Field & Grouping Field Key field: A value of the field uniquely determines a record in a file. Example: CID field Grouping field: A filed that can be used to group records: Example: City field, Rating field.

Basic File/List Processing Sorting: Data/Sort Two level sorting: Data/Sort/Add level Selecting records meeting criteria Data/Filter Text Filter: Begin with, End with, Contains, Number Filter: Top n, Above Average, Below Average Date Filter: Before, After, Next week, Last week, This month, Next quarter, This year, All dates in the period, etc. Compute subtotals Must sort list by grouping fields first Data/Subtotal Compute subtotals of two grouping fields

Example Student file What information can be retrieved from this file? SID Sname Major Sex GPA S1 Peter CIS M 3.0 S3 Paul ACCT M 2.7 S5 Mary CIS F 3.2 What information can be retrieved from this file?

Calculated Field A field whose value is derived from existing fields, for example, Age can be calculated from DateOfBirth. Age=Year(Today())-Year(DOB) Or Age=(Today()-DOB)/365

Calculated Grouping Field Examples: Age group Income group Academic performance group