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Part I Open a Access Database • Blank Database • Database Wizard • Existing Database (last five databases saved on the computer appear in the list box. If the file you want does not appear select More files…) The database window • This window will appear after selecting the database. Note it has the 6 database objects each on its own tab. Database Tables • Used to store data • holds field names, field descriptions and data for each field of each record • underlying structure for data stored in a database Table Selection • • • • • Datasheet View Design View Table Wizard Import Table Link Table Design View Database Table Columns in the Table Design • Field Name • Data Type - 10 types that are listed in a drop down box by clicking the arrow button on the column • Description Access Data Types • Text - any combination of alphabetic and numeric characters, such as names, addresses, and telephone numbers, that are not use in calculations (default) • memo - long entries requiring multiple lines of text, such as detailed descriptions and performance notes Access Data Types • Number - numeric values, such as the number of items or number of days worked that might be used in calculations • Date/Time - dates, such as date hired, and times, such as 1:00 • Currency - monetary values, such as salary Access Data Types • AutoNumber - numbers assigned by Access to uniquely identify each record; these values cannot be changed, deleted, or edited • Yes/No - Single-character entry fields that are marked when the status of the field is true (yes) or left blank when the status is false (no) Access Data Types • OLE object - fields that may be linked to an object, such as a picture or a document • Hyperlink - fields linked to other objects, Web pages, or documents that appear when the field when the field is clicked. • Lookup Wizard - fields that enable you to access a value from a table or list of values Filled in Table Design Datasheet View The Field Name(s) There are no records for this Database (yet) Records Added to Datasheet Two Views • Datasheet view - you see the field names as column headings and records as row. View multiple records on the screen. • Form view - forms use the fields and data that are stored in database tables to see one record on-screen at a time. Form View Maintenance • Change is inevitable. You will need add, delete modify information in your db • find, update, insert, replace, delete, sort, and filter and query. Find, Filter, Query Query language format examples Query Language • ask questions about the database • find the records which match a certain criteria Find or Filter or Query • Which one? Depends on preciseness. • All display or filter only the record(s) that match a specific criteria • note that there is also a FIND command in the word processing and spreadsheet tools. Find • usually used for error correction • used in searching for a particular value in a record. This command works the same way as it did for the spreadsheet. • you type in the dialog box • Find what: the entry you want to find. Depending on whether you unselected “current field”, Find searches each field (in the table) to look for a match. To Find Records in a DB Table • The binoculars on the toolbar • also can do find/replace (Edit->Replace) Find • Find can a search criterion with text or values anywhere in the table. This can be inexact. For example, if you used the find command to find an employee named Brown, the records of employees who live in the town Brown or on the street Brown could also be displayed. Filters • A Filter is an exact match. In a filter, Access only matches within a certain field. So in our last example, you would tell Access to find only NAMES (the field name) that are equal to Brown. Thus the other Brown matches are eliminated. Filters • To display (filter) only the record or records that satisfy a criterion. • Filter by selection is the simplest type of filter. • All you need to do is give Access an example of the data you want by selecting the data within the table, and then clicking the Filter by Selection button on the Form View toolbar (the sieve with the lighting bolt) Filter • In order to have all the records once again displayed, you remove the filter by clicking the Remove Filter button on the form toolbar. ( the sieve by itself icon) Filter/Query • Not saved • only within a single table • displays all the fields of “filtered” records • no other functions • Can be saved (it is one of the 6 objects) • multiple tables • displays only the fields you specified • queries can also be used to insert new values, modify field values and perform calculations on field values Database Window Queries Tab Previously Saved queries Three options you can do in queries section Queries • Click on tab marked Queries on the Database Window • There are three button on this window: – Open - If a previously saved query is highlighted, clicking this button will display the results of this query. – Design - If a previously saved query is highlighted, clicking this button will display the design query window filled in with the settings for this query. – New - An empty design query window will be displayed Queries • Note the table(s) used in the query display at the top. • If you clicked the Design button, the table(s) used in this saved query will be displayed. • If you clicked the New button, you will be given the opportunity of selecting the tables through the Show Table. Show Table Tables saved for this database To add tables to the query, highlight the table name and click Add. When finished click Close Query Design Window Back to Queries slide The Query Design Window • A Window that isolates the important parts of a query. (Design view) • Two Important parts to the Window: – Table(s) used in the query (top half) – The Query Grid ... Parts of the Query Design Window the table(s) used in the query Customers * Example of a selected table to use in a query, appears in the top half of the Query Design Window Customer Id First Name Table name Last Name Address Field Names Parts of the Query Design Window the query grid Drop down box of the Field Names from the selected tables Field: Table: Sort: Show: Criteria Or: Field • Drop down box, depends on the tables you selected to include either when the show table dialog box appeared (New) or from the original query (Design) . Once selected, the fields from the selected tables will be used in the query. Table: • You can select several tables for a query operation. • Once you have selected the Field , this entry is automatically entered by Access. Access will enter the table name of the field you selected. Sort: • You have the option of sorting the matching records • Just left click on the box and a drop down menu will appear, • Ascending, Descending and none • Can sort on more than one field, the first field listed (the leftmost) is the major key. • Remember only the query is sorted not the original table(s) Show: • If you want this field data to appear in the results • An empty Show box indicates that the field data will not appear in query results. • A checked Show box indicates that the field data will appear in query results. • Objective: remove unnecessary or duplicate fields Criteria • The final part, the criteria, (the comparison), determines how the query will do its comparisons. • Using expressions (just like Excel), combinations of field names, constant values, arithmetic and logic operators, you can restrict the number of records returned by a query Our Question (Query)? Who are our customers with the first name of John? (list them alphabetically) Customers * Customer Id First Name Last Name Address Select the Customers database This can be answered by a completing a Query Design Window. Customers Filled in Query Design Window * to Answer our Question Customer Id Display in alphabetical order the last names of customers with the first name of John First Name Last Name Address Field: First Name Customers Table: Sort: Show: Criteria “John” Or: Last Name Customers Ascending The Results • A list will appear when the run command is clicked, the ! Icon. Last Name Black Braithwaite Dewey Dickenson Dobbins Duran * Only Last Name field data displays Also note that the Johnaton(s) are not listed Must use wild cards * “John*” Access Automatic “FILL” • When you entered in the string John, Access will automatically place the quotes • John “John” • If you entered the string John*, Access will automatically change the field to • John* Like “John*” • Or you can put these in yourself. String Criteria • We can “match” strings for text type fields • We can use the wild cards * and ? for substitution of characters • * - 0 or more character substitution • Like “John*” – matches John, Johnaton, Johns, Johnstone – but not Jon, Jjohn • ? only one match and not anymore • Like “285?5???” – matches 285 5555, 285- 5555 – but not 765-285-5555, 1-285-5555, 285-51111 Our Next Question? Who are our customers with the first name of John or Susan? (list them alphabetically) Customers * Our database Customer Id First Name Last Name Address This can be answered by a completing a Query Design Window. Customers Design Query * Customer Id Display in alphabetical order the last names of customers with the first name of John or Susan First Name Last Name Address Field: First Name Customers Table: Sort: Show: Criteria “John” Or: “Susan” Last Name Customers Ascending The Results • A list will appear when the run command is clicked, the ! Icon. Last Name Black Braithwaite Dewey Dickenson Dobbins Duran Doolittle * Only Last Name field data displays Also you note that the Johnaton(s) and Susanne(s) are not listed. Must use wild cards * in strings “John*” “Susan*” OR • connectors • allows you to link comparisons to make it possible for you to analyze data in various ways • logical operators, because they act in comparisons the way mathematical operators work in the Spreadsheet Or Conjunction • when one or more of the conditions needs to be “true” we use the or conjunction • color equal to green OR color equal to yellow • color equal to green OR part number equal to 948 • one listed in the criteria row, the other in the or row Numeric Criteria - Logic Operators • • • • • • • Greater than (>) Less than (<) equals (=) greater than or equal to (>=) less than or equal to (<= not equal to (<> (same as Excel If expressions) Customers Design Query * Table name Customer Id First Name Last Name Address Total Purchase Age Display in descending order the total purchase of customers who are under 30 years of age Field: Table: Sort: Show: Criteria Or: Total Purchase Last Name Customers Customers Descending Age Customers <30 The Results • A list will appear when the run command is clicked, the ! Icon. * Total Purchase Last Name Age $1900.50 Smith 24 $1410.26 Buy 21 $1167.88 Jones 26 $900.88 Smith 20 $469.34 Feather 14 $367.99 Johnson 29 The query is sorted by the amount of the total purchase Orders Design Query * Table name Customer Id Order # Product ID # Quantity Display all orders which have not been paid by oldest date Field: Unit Price Table: Date of Purchase Sort: Date of Payment Show: Criteria Or: Order # Orders Date of Purchase Date of Payment Orders Orders Ascending Is Null Criteria • Null - the absence of data - an empty field. • If a field has no entry, it is called a null value. This is not the same as a space or zero! • The computer treats dates as if they were sequential numbers that increase with time The Results • A list will appear when the run command is clicked, the ! Icon. * Order # Date of Purchase Date of Payment 146678 3/10/2000 145778 3/12/2000 145807 3/15/2000 145900 3/19/2000 145910 3/21/2000 145950 3/24/2000 The query is sorted by the date of purchase Note that the Date of Payment could have been marked to not display. Orders Design Query * Table name Customer Id Order # Display all orders which were paid this month Product ID # Quantity Field: Unit Price Table: Date of Purchase Sort: Date of Payment Show: Criteria Or: Order # Orders Date of Purchase Date of Payment Orders Orders Ascending >=4/1/2000 The Results • A list will appear when the run command is clicked, the ! Icon. * Order # Date of Purchase Date of Payment 146578 3/02/2000 4/2/2000 145578 3/02/2000 4/2/2000 145607 3/05/2000 4/4/2000 145600 3/05/2000 4/5/2000 145710 3/06/2000 4/6/2000 145750 3/06/2000 4/6/2000 The query is sorted by the date of purchase Note that the Date of Payment could have been marked to not display. Access Automatic “FILL” • When you entered in the string >4/1/2000, Access will automatically place the # s • >=4/1/2000 >=#4/1/2000# • Or you can put these in yourself. Simple Selection Query Customers * Customer Id Display all of the customers with the name John Smith First Name Last Name Address Field: First Name Customers Table: Sort: Show: Criteria “John” Or: Last Name Customers “Smith” And Conjunction • The AND conjunction says that both conditions must be present for the record (row) to be queried • to combine criteria with AND, place the criteria on the same line Combining Multiple Conjunctions • when combining with all Ors - no problem • when combining with all Ands - no problem • when combining with both Ands and Ors order is important Customers Design Query * Customer Id First Name Display in alphabetical order the last names of customers with the first name of John or Susan that are older than 50 years of age. Last Name Age Field: First Name Table: Customers Sort: Show: Criteria “John” Or: “Susan” Last Name Customers Ascending Age Customers >50 The Records in the Database First Name Last Name Age David Done 33 Fred Flinstone 55 Susan Johnson 43 Susan Peters 34 John Peters 39 John Smith 55 Susan Smith 52 Result of Query First Name Last Name Age Susan Johnson 43 Susan Peters 34 John Smith 55 Susan Smith 52 Note that the records matched any record with the first name of Susan and records that had the first name of John and were older than 50 (FirstName = “John” AND Age > 50) OR FirstName = “Susan” But what if wanted only those records with first name of Susan who were age 50 or older or records with the first name of John who were age 50 or older … or First Name Last Name Age John Smith 55 Susan Smith 52 Note that the records matched any record with the first name of Susan and records that had the first name of John and were older than 50 (FirstName = “John” OR FirstName = “Susan”) AND age > 50 Customers Design Query * Customer Id First Name Display in alphabetical order the last names of customers with the first name of John or Susan that are older than 50 years of age. Last Name Age Field: First Name Table: Customers Sort: Show: Criteria “John” Or: “Susan” Last Name Customers Ascending Age Customers >50 >50 Result: First Name Last Name Age John Smith 55 Susan Smith 52 Note that the records matched any record with the first name of Susan who was older than 50 years of age or records that had the first name of John who were older than 50 years of age. (FirstName = “John” and age > 50) OR ( FirstName = “Susan” and age > 50) Three fields using AND and OR Meaning • Be careful of the wording when designing queries. • For example if I asked you to give me a list of classes that are held at 9:00 A.M and 10:00 A.M, I am using the word AND to mean both (not the connective AND) • BOTH-> OR Questions