CIS-145 FinalCIS-145 Final

• 100 points• Open book, open notes, open

computer• True-false, multiple choice, fill-in,

short answer

DatabasesDatabases

• Collection of related information– Scope is based on what information we

need to complete tasks

• Access uses seven objects to organize and manage data– Tables, queries, forms, reports,

macros, modules– All objects are in one file

TablesTables

• Fields are individual data elements/values - columns

• Records are the collection of data for one occurrence – rows

• Table should be about one thing or idea

• Primary key uniquely identifies each record

Table DesignTable Design

• Include all necessary data• Store data in smallest parts• Don’t include calculated fields

Field Data TypesField Data Types

Common Types• Number• Currency• Text• Yes/No• Date/Time

What kind of data will be stored in the field?

Numbers not used for calculations should usually be text.

PropertiesProperties

• Set specific characteristics and behaviors of objects (fields, controls, or other objects)

• Properties set for a field are inherited by controls that refer to that field– Drag field from field list in form design

view

Data ValidationData Validation

• Need to make sure we have good data - proper type and values

• Properties can help with validation:– Field Size: How much data to accept– Input Mask: How or what data is

entered– Format: How data is displayed– Validation Rules: What data is

acceptable– Required: value must be entered

Relational DatabasesRelational Databases

• Have more than one table where tables are related to each other– One to one– One to many– Many to many

• A combination of fields may be used for the table’s key

One to Many One to Many RelationshipsRelationships

• Each table contains data about a specific subject (customers, loans)

• Each table on the ‘one’ side has a primary key

• Primary key of the “one” table is used to create a foreign key in the “many” table

Many to Many Many to Many RelationshipsRelationships

• Two tables are related, but can have many records in each table in common– One student can attend many courses;

one course can be attended by many students

• Implement a many to many relationship by creating a pair of one to many relationships with a third (join) table

Foreign KeyForeign Key

• A foreign key points to a record in another table

• Foreign key “looks like” the related primary key– Same number of fields– Data types for each field must match– Field names don’t matter

Referential IntegrityReferential Integrity

• Makes sure that the records in related tables are consistent– Must have a customer in the customer

table for an order assigned to that customer

– Avoids “orphans”

• Can’t delete a record or change the primary key in the one table when associated records are in the many table, unless have cascade delete and cascade update enabled

Relationships WindowRelationships Window

• Where relationships between tables are created and defined

• Related fields must have the same data type– Autonumber is related to number field

with long integer field size

• The one table has a 1 next to it; the

many has a next to it

Select QueriesSelect Queries

• Select Queries represent a question and an answer

• Question is created in design view– Design view creates a Structured

Query Language (SQL) statement

• Answer is shown in datasheet view– Answer is a dynaset - dynamic subset

of a table

Query DesignQuery Design

• Specify data source - table or another query (FROM)

• Determine which rows to include (WHERE)

• Identify groups (GROUP BY)• Specify groups to include in result

(HAVING)• Identify fields to include in result

(SELECT) • Specify how to sort the answer (ORDER

BY)

And Or

CriteriaCriteria

WildcardsWildcards

• ‘*’ is for a group of characters (0, 1 or more characters)

• ‘?’ is for a single character (and there must be a character)

“S*ND” will return sand, sound, send, stand, spend

“S?ND” will return sand, send

Total QueriesTotal Queries

• Select query with results summarized by one or more fields– Find value(s) that records share and

summarize information

• Similar to Groups in a Report

Multi-table QueriesMulti-table Queries

• Can use multiple tables in a query• If tables are not already related,

can connect tables in the query itself– Drag the connecting field from the one

table to the many table

• “Joins” describe how rows in one table match rows in the other table(s)

JoinsJoins

• When using multiple tables, need to connect through a join

• Inner-join is most common and requires matching values in both tables

• Outer-join includes all rows from one table and any matching records from second table that exist

• Cartesian Join matches all rows from one table with all rows from 2nd table

Autolookup QueriesAutolookup Queries

• Use queries to automatically look up data from related tables

• Must contain the foreign key from the many table– Value entered in foreign key is

matched to value in related primary key to “look up” data

• Can add, change or delete data in the source tables– Many side will determine where a new

row is added or existing row deleted

Parameter QueriesParameter Queries

• Parameter queries allow entry of criteria when query is run– A “place holder” allows the criteria to

be saved without a specific value– Behaves like an argument in other

programming languages

• Allows query to be used with different values without having to go into design view

Action QueriesAction Queries

• Action queries are about change• Can change data

– Update: change an existing value– Append: add rows to a table– Delete: remove rows from a table

• Can change database– Make-table: create a new database

object

FormsForms

• Basic use is to enter and display information from a table– Forms can also help to change data

stored in table by being bound (record source is a table or query)

• Forms can help others use an application•Typically an unbound form (no

record source)• Forms use controls: bound, unbound,

calculated

Forms - 2Forms - 2

• Forms have sections: header, footer, and detail– Detail section is used to display data

from one row in a table or query

• Tab order controls how the cursor moves through controls on a form

Forms & SubformsForms & Subforms

• Main form is based on the primary (“one”) table

• Subform is based on the many table• Subform shows records associated

with the current record in the primary table

• Each form has its own status bar, record selector, and navigation buttons

SubformsSubforms

• Main form and subform are linked through specific fields; fields don’t have to be shown, but must be in data source (record source)

• A main form can have several subforms• Subforms can be displayed as a data

sheet, single form or continuous forms– Display is set through the form’s

default view in the properties window

List ControlsList Controls

• A list or combo box can be bound to a field in one table, and display data from fields in a second table– Good choice for selecting a value for a

foreign key, if the primary and foreign keys are single fields

• Rowsource property specifies the list of choices, bound column specifies the value to save

• Can show/not show different columns in the list

ReportsReports

• Displays information from a table or query

• Cannot change data– A report shows the data at the time of

printing or print preview– Each time a report is displayed or

printed, it recalculates and re-reads the data from tables, so one report can show different values

Reports - 2Reports - 2

• Reports have sections: report, page, and group headers and footers; and detail

• Controls are used to display data, information, calculations– The most common controls are text

boxes, labels, and lines

Sorting & GroupingSorting & Grouping

• Groups help to organize data into information for records that have something in common– Can summarize information for

subgroups (for example, showing subtotals by location)

• Sorting controls the order that information is shown

SubreportsSubreports

• Allow main report to include all records, regardless of whether there are related records– Subreports are similar in function to

subforms, finding related rows for the current row in main report

• Can include several subreports, if a query would create incomplete or duplicating results

Getting & Using Data in Getting & Using Data in Forms and ReportsForms and Reports

• Forms and reports have a recordsource property– Can get data from a table or query

• Bound controls use the controlsource property to connect to a field– Field for controlsource must be in form

recordsource– Controlsource is also used for

calculations