ICDL Databases flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Database

An organised collection of related data stored so it can be efficiently retrieved, managed, and updated by users or applications.

DBMS

Database management software that sits between users and stored data, enforcing structure, security, and access rules. Examples include Access and MySQL.

Record

A single row in a table that holds all the field values describing one instance of the entity, such as one customer.

Field

A column in a table that stores one attribute for every record and has a defined data type and set of properties.

Primary key

A field or combination of fields that uniquely identifies each record in a table; it cannot contain duplicate or null values.

Foreign key

A field in one table that holds values matching the primary key of another table, creating a link between the two tables.

Data redundancy

Storing the same fact in more than one place; it wastes space and risks inconsistent data when only one copy is updated.

Autonumber data type

A numeric field type that automatically assigns a unique sequential number to each new record, commonly used as a primary key.

One-to-many relationship

A relationship where one record in the parent table relates to many records in the child table; the foreign key sits on the many side.

Many-to-many relationship

A relationship requiring a junction table that holds foreign keys to both parent tables, since neither can store a single reference.

Referential integrity

A rule ensuring every foreign key value matches an existing primary key value, or is null, preventing orphan records.

Cascade delete

An option that, when referential integrity is enforced, automatically deletes related child records when the parent record is deleted.

Validation rule

A logical expression applied to a field that must evaluate true before data is accepted, such as >=0 And <=100 for a percentage.

Input mask

A field property that controls the format and number of characters users can enter, such as a fixed pattern for a phone number.

Design view

The table window used to define field names, data types, and properties rather than to enter or edit actual record data.

Indexed field

A field property that builds a lookup structure to speed searching and sorting, at the cost of slower inserts and updates.

Select query

A query that retrieves records matching specified criteria and displays them without altering any stored data in the tables.

AND versus OR criteria

Criteria placed on the same design-grid row combine with AND, requiring all conditions; criteria on separate rows combine with OR.

Wildcard characters

Symbols used with the Like operator in criteria: * matches any number of characters and ? matches exactly one character.

Parameter query

A query that prompts the user for input at run time using a bracketed prompt such as [Enter a date] placed in the criteria row.

Aggregate function

A function such as Sum, Avg, Count, Min, or Max that calculates a single summary value from many records in a totals query.

Calculated field

A query column created from an expression, for example Total: [Quantity]*[UnitPrice], that can be sorted and filtered like any field.

Is Null criterion

A query criterion that finds records where the field contains no value; Not Is Null returns records where the field is populated.

Inner join

A query join that returns only rows where the joined fields match in both tables, excluding unmatched records from either side.

Bound control

A form or report control connected to a specific field in the underlying table or query, displaying and editing that field's data.

Unbound control

A form control with no link to a data field, such as a label, line, or command button used for display or actions.

Main form with subform

A form design that displays one parent record together with its related child records, presenting one-to-many data on a single screen.

Combo box

A form control that shows a drop-down list of values and can restrict entry to those listed options.

Tab order

The property controlling the sequence in which controls receive focus as the user presses the Tab key through a form.

Report sections

Areas of a report: report header and footer appear once, page header and footer on each page, group sections per group, detail per record.

Grouping in a report

Organising report records by a field value so a group header and footer appear for each distinct value, enabling subtotals.

Export to PDF

Saving a report output as a fixed-layout file that preserves pagination and formatting and is not easily edited by recipients.