Intermediate MS Access Instructor: Vicki Weidler Assistant: Adam Cavotta

Unit 9: Creating Relational Databases

Overview Normalize tables to reduce data redundancy Understand the requirements for first, second, and third normal forms Set one-to-one, one-to-many, and many-to-many relationships between tables Implement referential integrity between related tables Use cascading deletes and updates to prevent orphan records

Normalization The process of restructuring data files to: reduce data to its simplest structure minimize redundancy achieve the most efficient and functional yet flexible way to store data

First Normal Form (1NF) Eliminates duplicate data… a table should not contain similar information in several fields; eliminate duplicative columns from the same table or move repeating fields to a related table a table should not contain fields that can be further broken down into smaller meaningful parts create separate tables for each group or related data and identify each row with a unique column (the primary key); each table should describe a single entity (object) class Definition 1NF

Second Normal Form (2NF) Requires all data in the table apply directly to the subject of the table indicated by the primary key field… if the table has a single-field primary key and meets the requirements for 1NF, then it also meets the requirements for 2NF however, if the table has a composite (multiple-field) primary key, then all the fields in the table must be related to and/or dependent on ALL the fields of the composite primary key to convert a table to 2NF, find all the fields that are related to only part of the composite (multiple-field) primary key, group these fields into another table, then assign a primary key to the new table another way of looking at it is to remove ALL subsets of duplicate/redundant data that apply to multiple rows of a table and place them in new tables, then create relationships between these new tables and the original tables by using foreign keysDefinitionDefinition 2NF

Third Normal Form (3NF) Eliminates fields that can be derived from other fields… if a table contains fields that do not relate to and are not fully dependent on the primary key and completely describe the object that table represents, then it is not in 3NF to convert a table to 3NF, delete all the fields that do not relate to the primary key Definition3NF

Fourth Normal Form (4NF) Requires that tables not contain fields for two or more independent, multi-varied facts… this rule requires splitting tables that consist of lists of independent attributes i.e. in a relation table, job skills and language fluency are independent facts about an employee; therefore, the 3-field relation table must be split into 2 two- field relation tables

1French 2German 3Russian 4Spanish 1Project Mgmt 2Supervisory 3Software 4Organization 1JohnDoe 2JaneSmith 3BobHealy 4ElaineAnderson

Employee Code Language Employee Code Job Skill

Fifth Normal Form (5NF) Requires the capability to reconstruct the source data from the tables that have met 1NF, 2NF, 3NF and 4NF… you should be able to regenerate from the database a spreadsheet that contains all the data in the original version this is an “acid test” for normalization and requires considerable skill in designing queries to join related tables to produce a readable output to compare with the original data

Relating Tables Relationshipsused to extract data from several tables at the same time Primary keyunique identifier for each record in a table Foreign key the primary key in the related table

Types of Relationships One-to-One Relationship When one complete record in the primary table is related to just one record in the related table and vice versa; both tables are equally dependent on each other One-to-Many Relationship When one record in the primary table is related to several records in the related table; however, a record in the related table has only one related record in the primary table Many-to-Many Relationship When several records in one table are related to several records in another table. A many-to-many relationship cannot be created directly in MS Access. To relate such tables, you must first create a junction table that contains the primary keys of both tables

Referential Integrity Ensures that changes made to one table will be reflected in the related table Orphan Records When a record is deleted in the primary table without deleting the related records in the other table

Referential Integrity Cont. Cascading Deletes When you delete a record from the primary table, cascading deletes automatically deletes all related records from other related tables; this ensures that there are no orphan records Cascading Updates When you change a primary key in a table, the change is updated in all of the related tables

Summary Normalize tables to reduce data redundancy Understand the requirements for first, second, and third normal forms Set one-to-one, one-to-many, and many-to-many relationships between tables Implement referential integrity between related tables Use cascading deletes and updates to prevent orphan records

Independent Practice Activity

Unit 10: Working with Related Tables

Overview Create Lookup lists using the Lookup Wizard & Design View Modify Lookup field properties Learn how to change control types Add data to related tables utilizing a subdatasheet

Lookup Wizard The Lookup Wizard creates a field in one table that gets data from a field in another table. This is called a Lookup list field. The Lookup field uses the primary key from the related table to ensure referential integrity.

Table Control Types Text Box used to enter data in a table; cell Combo Box drop-down list of values; you can either select a value from the list or enter a value not on the list List Box drop-down list of values; unlike the combo box, you can only select a value from the list, you cannot enter a value that is not on the list

Adding Data to Related Tables Subdatasheet Set of records extracted from a table based on a record in another table Use to view and enter data in related tables

Summary Create Lookup lists using the Lookup Wizard & Design View Modify Lookup field properties Learn how to change control types Add data to related tables utilizing a subdatasheet

Independent Practice Activity

Unit 11: Defining Data Entry Rules

Overview Create field input masks using the Input Mask Wizard Set Required, Allow Zero Length, and Field Size properties Define validation rules and text for entering data in a field

Input Masks Input masks allow you to control the way data is entered in a field First section contains the input mask Second section determines whether to store literal characters with the values that are entered Third section specifies placeholder characters

Input Mask Characters CharacterDescription 0Must enter a number between 0 and 9 9Can enter a number or space (0 through 9), but entry is not required #Can enter a number or a space; entry is not required and all blank positions will be converted to spaces LMust enter a letter, A through Z ?Can enter a letter, A through Z, but entry is not required AMust enter either a letter or a number aCan enter a letter or a number, but entry is not required &Must enter a character or a space CCan enter a character or space, but entry is not required <Any letter that follows will be converted to lowercase >Any letter that follows will be converted to uppercase

Setting Properties PropertyDescription RequiredUsed to specify that a field is required and a value must be entered in it AllowZeroLengthUsed to specify that the field can contain null values Field SizeUsed to specify the maximum number of characters that can be entered in the field

Validation Rules You can set conditions on types of data, data format, or number of characters that can be entered in a field. If the data entered in the field violates the validation rule, Access automatically prompts for a correct value.

Setting Validation Rules RuleDescription Like “S???”The value in the field should have 4 characters and the first character should always be an S <>0The value in the field should not be equal to zero 0 or >100The value in the field should be 0 or greater than 100 <#1/1/2000The date in the field should be earlier than January 1, 2000

Validation Text When a validation rule is violated, you can display your own text in the warning message box.

Summary Create field input masks using the Input Mask Wizard Set Required, Allow Zero Length, and Field Size properties Define validation rules and text for entering data in a field

Independent Practice Activity

Unit 12: Using Advanced Query Features

Overview Understand the differences between outer, inner, and self-join queries Design outer, inner, and self-join queries Generate calculated fields in a query Modify the format of a displayed value Use the expression builder Create queries to add, delete, and modify data in a table and to produce new tables

Joins Queries that include data from more than one table are called joins. A join tells MS Access how the data between tables is related. You can create: Outer joins Inner joins Self-joins

Outer Joins An outer join is a query in which all of the records from one table are joined to only matching records from another table.

Inner Joins If one table does not have a matching record in the second table, then no records from either table will appear in the query results. To avoid this, you can use an intermediate table to extract data from the original two tables. This intermediate, or join table, acts as a bridge between two tables that don’t have any related fields. This is used when a many- to-many relationship exists between two tables and uses primary keys from both tables to extract the data from the intermediate join table.

Self-Joins A self-join is a query that displays matching records from the same table when there are matching values in two fields.

The Expression Builder

Action Queries Action queries perform certain actions in tables. There are four types: Append-append data from one table to another Delete-delete records from tables based on specific criterion Update-update data in different tables at the same time Make-Table-creates a table from the result of a query

Summary Understand the differences between outer, inner, and self-join queries Design outer, inner, and self-join queries Generate calculated fields in a query Modify the format of a displayed value Use the expression builder Create queries to add, delete, and modify data in a table and to produce new tables

Independent Practice Activity

Unit 13: Creating Advanced Queries

Overview Use a select query to summarize and group data from different tables Write a concatenation statement to combine values from different fields Use the Find Unmatched Query Wizard to locate records that do not match between tables Design a crosstab query to summarze grouped data Create single- and multiple-criteria parameter queries Learn how to use a wildcard in a parameter query Create single- and multiple-field indexes to quickly sort and filter data in a table

Concatenation Concatenation is the process of combining values from different fields into one field

Find Unmatched Queries Use a Find Unmatched Query to view records that don’t have a matching record in another table Example: Locate customers who don’t have matching entries in the Orders table.

Crosstab Queries Display a summary of values based on two different types of information. Generally used to display large amounts of data in a compact format for easy review. Used to calculate averages, sums, or other totals on records, then group the results into two types of data. One group runs down the left side of the datasheet while the other runs across the top.

Parameter Queries A parameter query displays results based on criteria you specify each time you run the query. One or multiple parameters can be used.

Indexes Indexes are used to quickly sort and find data in tables. An index performs a search based on key values. Primary keys are automatically indexed.

Summary Use a select query to summarize and group data from different tables Write a concatenation statement to combine values from different fields Use the Find Unmatched Query Wizard to locate records that do not match between tables Design a crosstab query to summarze grouped data Create single- and multiple-criteria parameter queries Learn how to use a wildcard in a parameter query Create single- and multiple-field indexes to quickly sort and filter data in a table

Independent Practice Activity

Unit 14: Creating Advanced Form Design

Overview Add a graphic control to a form Embed a graphic in an unbound object frame Bind a control to a calculated field Add calculated fields to a form Insert a combo box and modify its properties Format controls in a form Insert unbound controls Change the control tab order

Controls Unbound – not linked to any field in a table or a query Bound – linked to a field in a table or query Calculated – used to display a calculated value based on one or more fields in a table or query

Summary Add a graphic control to a form Embed a graphic in an unbound object frame Bind a control to a calculated field Add calculated fields to a form Insert a combo box and modify its properties Format controls in a form Insert unbound controls Change the control tab order

Independent Practice Activity

Unit 15: Using Advanced Report Features

Overview Create customized headers and footers Set properties to group data and modify a report’s appearance Use functions to add calculated values in a report Apply conditional formatting Embed a subreport in a main report View and troubleshoot report results

Report Headers & Footers Header – first page of report & includes logo, image, report title Footer – last page of report & includes details such as report totals

Conditional Formatting Conditional formatting draws attention to data in a report if it meets specified criterion.

KeepTogether Property The KeepTogether property ensures that a complete section of the report is always printed on one page.

Group Footers Group footers are used to group a report based on a given field. Use to add information such as group totals or group names

ForceNewPage Property To print each set of related data on a separate page, you can use the ForceNewPage property. Can be used in all sections EXCEPT the page header & footer sections. Can insert pages before a section, after a section, or both.

HideDuplicates Property To display only the unique values in each field of a report, you can use the HideDuplicates property.

DateDiff Function Used to calculate the difference between two dates. DateDiff (“interval”, [date1],[date2]) “Interval” refers to whether the calculation is the difference between days (d), months (m) or years (y). Both fields must have Date/Time data types in order for this function to work properly.

IIF Function Used to evaluate a condition. If a condition is true, the IIF function returns one value. If it is false, it returns a different value. IIF (condition, value_if_true, value_if_false) is the syntax for the function. Condition means the condition you want the function to evaluate. Value_if_true is the value to be returned if the condition is true. Value_if_false is the value to be returned if the condition is not true.

Subreports Used to display data from two different reports. A subreport is embedded in a main report. Generally, the main report and subreport share a common field by which they are linked.

Summary Create customized headers and footers Set properties to group data and modify a report’s appearance Use functions to add calculated values in a report Apply conditional formatting Embed a subreport in a main report View and troubleshoot report results

Independent Practice Activity

Unit 16: Creating Charts & Data Access Pages

Overview Create and modify a chart in a form Create and modify a chart in a report Understand the difference between record-based and global charts Create a data access page

Charts in MS Access Record-Based – displays data based on the active record & changes each time you navigate to a new record Global – chart remains the same no matter what record you display

Data Access Pages Web pages that allow you to view, add, edit, or delete data in the source MS Access database You can sort, filter or group data using data access pages

Summary Create and modify a chart in a form Create and modify a chart in a report Understand the difference between record-based and global charts Create a data access page

Independent Practice Activity

Resources Questions & Answers Evaluations Thank You!!! Conclusion