Microsoft Access 2010 Tables & Field Properties

Transcription

1 Microsoft Access 2010 Tables & Field Properties Web Page:

2 Microsoft Access Tables & Field Properties 2.0 hours Tables are the core of our database, where all data is saved. The other database objects, Queries, Forms and Reports, use the data from the tables. The topics for this workshop include working with different data types; data entry shortcuts; the table analyzer wizard; simple relationships; AutoForms; and field properties such as: field size, formats, input masks, captions, default values, and validation rules. Access Basics highly recommended as a prerequisite. New Database... 1 Creating New Tables... 1 Create Tables from Existing Data... 3 Analyze Table... 3 What is Normalization?... 3 Table Analyzer Wizard... 3 Data Types... 8 A note about AutoNumbers... 9 General Properties... 9 Field Size New Values Expression Result Type Format Decimal Places Input Mask Caption Default Value Validation Rule Validation Text Required Allow Zero Length Indexed Unicode Compression IME Mode IME Sentence Mode Smart Tags Text Format Text Align Show Date Picker Append Only Workshop Exercise Pandora Rose Cowart Education Coordinator Academic Health Center Training Updated 11/29/2015 C3 013 Communicore (352) PO Box prcowart@ufl.edu Gainesville, FL

3 New Database When you first create a database in Microsoft Access 2010, it takes you directly to a new table screen, in a Datasheet view. From here we can start to entering data and naming our fields. To change the name of the fields, double click on the column heading, to add a new one, double click on Add New Field. There will always be an Add New Field column at the end of your data set in the table Datasheet View. If you create your table this way, Access will assume the data type based on the entries. Creating New Tables On the Create tab there are several options to create a new table. The first option, showing just a grid creates a table using the Enter Data mode shown above. Field properties can be modified through the Table Tools Fields Tab. You won't be able to change all the properties, for that you will need to move to the Design View. The next button allows you to create your Table in the design view. In the basics workshop you created two tables in the design view. If you have planned your database, this will be the best way to make a new table. Even if you begin a table using one of the methods above you will eventually need to make modifications in the design. Creating a table in Design View is talked about later in this packet. The SharePoint Lists will create a table and the links necessary to use the data collected in this database for a SharePoint file. Page 1

4 Creating a Table in Design View When you choose this method to create a table you will see a blank design view. Notice at the bottom of the screen, the blue text tells you what you are filling in. In this case, the field name, Access is telling you that the name can be up to 64 characters long, counting the spaces. It also tells us that F1 will bring up the help file for field names. Watch this area for explanations of each portion of the Design view. Access will tell you if you use a character it does not allow for a field name: Once you have typed your field a name, you can choose a data type. By default the fields will be text. Text Alphanumeric characters up to 255 (including spaces) Memo Alphanumeric characters up to 64,000 (that s more than10 pages at 10 pt font) Number True number fields, no letters. A number is data we would do math with. Date/Time For Dates and Times Currency Special Number field with $ AutoNumber Automatic numbers created with each new record Yes/No True Boolean Yes or No No maybes, no blanks. True or False, Yes or No OLE Object Object Link or Embed. (from 2003, use attachments or hyperlinks) Hyperlink Link to a webpage or to a file on your computer Attachments Allows you to attach an outside file to individual records (new to 2007) Calculated Allows you to create a calculation based on the data (new to Office 2010) Lookup Wizard Create a combo box like this Data Type List The description column is for more than just programmer notes. The text you type in the Description will be displayed in the status bar in the Datasheet View of the table. Page 2

5 Create Tables from Existing Data You can bring existing data into your Access database if you have a data table already created in another file, such as an Excel Spreadsheet, a comma delimitated (CSV) file, or other data file that is organized and ready bring into the current database (including other Access files). On the External Data tab, there are several Import & Link options. See the Access 2010: Importing and Exporting with Excel handout for more information. Analyze Table At the end of the Table Import Wizard we have the option to analyze our new able. This option is available at anytime from the Database Tools Tab (for Office 2003 look in the Tools Menu, under Analyze). This analyzer helps us to "normalize" our data. This will help us separate the repetitive data into its own table. Doing this will cut down on data entry errors and help us to maintain a data consistancy. What is Normalization? Normalization is the process of efficiently organizing data in a database. There are two goals of the normalization process: eliminating redundant data (for example, storing the same data in more than one table) and ensuring data dependencies make sense (only storing related data in a table). Both of these are worthy goals as they reduce the amount of space a database consumes and ensure that data is logically stored. ( Table Analyzer Wizard Step 1: Looking at the Problem Page 3

6 Step 2: Solving the Problem Step 3: Choosing which Table to Analyze The "Show introductory Pages?" box will allow Access to open the newly created tables at the end of the wizard. Page 4

7 Step 4: Deciding to use the Wizard or your own plan Step 5: Restructuring your Tables Page 5

8 For this class we want to split our Visits Table into three new tables. Our reasons have a lot of repeated data that will probably work best from a lookup table. Our Doctors are also being repeated, and even more so here where we must repeat several fields for each record. Access will pull out the unique values for the new table, set an automatic Primary Key and create a lookup in the original dataset to the new table. Page 6

9 Step 6: Correcting possible Typographical Errors If Access finds inconsistencies in the dataset it will prompt you for possible corrections. Step 7: Decide on Query and Finish Page 7

10 The Table Analyzer Wizard has not been changed for several versions of Access. In Access 2003 and earlier the "introductory" pages (the new tables) open tiled horizontally. In Access 2010 we used Tabbed Documents, more than Floating Windows. The Tabbed documents cannot be tiled, so you will get this error message. Just click ok to view your new tables. Access does not touch the original table. If you are happy with the results of the new table structures, be sure to remove the old table from your database. Data Types Data Type Text Memo Number Date/Time Currency AutoNumber Description Text can contain any alphanumeric characters, up to 255 characters (letters, numbers, and symbols, including punctuation). Memo can contain any alphanumeric characters, up to 65,535 characters (letters, numbers, and symbols, including punctuation). A Number field is limited to numeric input (numbers, decimal points, +/ signs). This is a field that can be used for mathematical purposes. Date/Time allows you to enter Dates and/or Times. Access will store these dates and times similarly to Excel, such that you will be able to do math with them. This field type is a monetary value, accurate to four decimals. This field is most often used as a primary key, because it creates a unique sequential number for each record. Page 8

11 Data Type Yes/No OLE Object Hyperlink Attachment Lookup Wizard Description This is a binary field, its format can be set to Yes/No, True/False, or On/Off. In each of these cases, there are only two options. OLE stands for Object Linked or Embedded. This is the option you would use if you needed to embed or link a file to a record. A hyperlink data type would be used for addresses or web pages. Allows you to attach a file to the record. Attachment fields provide greater flexibility than OLE fields, and they use storage space more efficiently. The lookup wizard allows you to link the field to another table, in order to set up a drop down arrow to choose your data from the other table or query. This will automatically link the two tables A note about AutoNumbers When AutoNumbers are set to increment the field will count in ascending order (1, 2, 3). When a record is deleted, the table is not renumbered*. AutoNum Name AutoNum Name AutoNum Name 1 Jack 1 Jack 1 Jack 2 Jill 2 Jill 3 John 3 John 3 John AutoNumbers can be random instead of incremented. This allows the data to be shuffled, instead of being displayed in the order you created the records. Random numbers are treated the same as the incremented numbers. When the record is deleted its AutoNumber is gone. *In Access 2007/2010, you can delete the AutoNumber field you have created, and the table will forget the previous AutoNumber. If you create a new field as an AutoNumber, this version of Access will create a new count for you. In older versions of Access you will need to move the data to a new table to create a new AutoNumber. General Properties Each data type has different field properties that will appear at the bottom of the screen. These are the general properties for a text field. The properties will change depending on the data type. Access provides a brief description of each properties in blue text on the on the right side of the window. Page 9

12 Field Size Text The maximum number of characters including spaces is 255. If you need more than 255 characters, a Memo field can hold up to 65,535 characters (including spaces). If you need more than a Memo field can hold, you should place the text in an outside file, such as Word, and link to it with a Hyperlink field or embed it using an OLE field (2003 or earlier) or attach it using the Attachment field (2007 or later). Access will hold the text field to the limitation you set, for example for a "State" field you may limit the field size to two, so that the user will only be able to enter the abbreviations, "FL" instead of "Florida". Access only saves the characters that are actually entered, no matter how large the Field size setting is for text fields the storage size is only measured by the true contents. Number, AutoNumber The field size of a Number or AutoNumber determines the range of the number as well as the size of the memory storage. Setting Description Storage Size Byte Stores numbers from 0 to 255 (no fractions). 1 byte Integer Stores numbers from 32,768 to 32,767 (no fractions). 2 bytes Long Integer Single Double (Default) Stores numbers from 2,147,483,648 to 2,147,483,647 (no fractions). Stores numbers from 3.40E38 to 1.40E 45 for negative values and from 1.40E 45 to 3.40E38 for positive. (7 significant digits) Stores numbers from 1.8E308 to 4.9E 324 for negative values and from 1.8E308 to 4.9E 324 for positive values. (15 significant digits) 4 bytes 4 bytes 8 bytes Decimal Stores numbers from 10^28 1 through 10^28 1 (30 significant digis) 12 bytes Replication ID Do not use this value unless you are working in or implementing the design of a replicated database. 16 bytes New Values AutoNumber This General Property only appears with AutoNumbers. The options are Increment, which means the AutoNumber will count each record, 1,2,3, or Random, which means the AutoNumber will randomly choose a number within the field size to represent that record. Expression Calculated This General Property only appears with the calculated field. The field type will be "calculated", but this Expression property shows the true equation/expression. Page 10

13 Result Type Calculated This General Property only appears with the calculated field. The options allow you to determine the field type and numeric field size of your result. Format Text, Memo, Hyperlink, Calculated The selection box for these formats are empty, but you can create a few custom formats: < (lowercase), > (requires data, at least a space), & (data not required) Setting Data Entered @@@@ > HSC/ITC Training HSC/ITC TRAINING < HSC/ITC Training hsc/itc training Null value (leave blank) Unknown HSC/ITC Training HSC/ITC Training Number, Currency, AutoNumber, Calculated There are several options for the number format: Setting General Number Currency Euro Fixed Standard Description (Default) Display the number as entered. Use the thousand separator Use the euro symbol, regardless of the currency symbol specified in the regional settings of Windows. Display at least one digit, set Decimal places property with this format Use the thousandth separator with two decimal places Percent Multiplies the value by 100 and append a percent sign (%) Scientific Use standard scientific notation. 4,000,000 = 4.00E+06 Page 11

14 It is possible to create your own custom Number formats. Custom number formats can have one to four sections with semicolons (;) as the list separator. Each section contains the format specification for a different type of number. Section First Second Third Fourth Description The format for positive numbers. The format for negative numbers. The format for zero values. The format for Null values. For example, you could use the following custom Currency format: $#,##0.00[Green];($#,##0.00)[Red];"Zero";"Null" You can create custom number formats by using the following symbols. Symbol Description. (period) Decimal separator. Separators are set in the regional settings in Windows., (comma) Thousand separator. 0 Digit placeholder. Display a digit or 0. # Digit placeholder. Display a digit or nothing. $ Display the literal character "$". % Percentage. The value is multiplied by 100 and a percent sign is appended. E or e Scientific notation with a minus sign ( ) next to negative exponents and nothing next to positive exponents as in 0.00E 00 or 0.00E00. E+ or e+ Scientific notation with a minus sign ( ) next to negative exponents and a plus sign (+) next to positive exponents, as in 0.00E+00. Examples: General # # $0.00 $0.00 $12.00 $12.35 $ $0.12 Currency $0.00 $12.00 $12.35 $12,345, $0.12 Euro ,345, Fixed Standard ,345, Percent 0.00% % % % 12.35% Scientific 0.00E E E E E 01 Page 12

15 Date/Time, Calculated The preset formats for the Date/Time field are shown on the left. As with our Number field, Date/Time fields are not limited to the options given, we can build our own custom formats. If you wish to make your own date/time format use the table below as a guide. Dates for Tuesday, February 3, 2004 Day Month Year d 3 m 2 dd 03 mm 02 ddd Tue mmm Feb dddd Tuesday mmmm February Times for 1:02:05 yy 04 yyyy 2004 Hours Minutes Seconds h 1 n 2 s 5 hh 01 nn 02 ss 05 If you would like to use the 12 hour clock you need to add the appropriate designator at the end. Access will accept any of the following: AM/PM; am/pm; A/P; a/p; AMPM. If you want to add a comma or other separator to a custom format, enclose the separator in quotation marks as follows: mmm d", "yyyy. Symbol Description Examples: ddddd Same as the Short Date predefined format. Setting Result ddd", "mmm d", "yyyy Mon, Jun 2, 1997 mmmm dd", "yyyy June 02, 1997 "This is week # "ww This is week # 22 "Today is "dddd Today is Tuesday dddddd Same as the Long Date predefined format. w Day of the week (1 to 7). ww Week of the year (1 to 53). q Quarter of the year (1 to 4). y Number of the day of the year (1 to 366). ttttt Same as the Long Time predefined format. Yes/No, Calculated The preset formats for the Yes/No field are Yes/No, True/False, or On/Off. It is possible to create custom formats as well, however, no matter which format you choose you will only see the check box in the datasheet view. To change the check box into a Text field so you can see your formatting options, you must go to the Lookup properties tab and change the Display Control to a Text Box. To build a custom format you must start with a leading semicolon (;) then what to do if the item is true, a semicolon, and what to do if it's false. Example: ; Always (blue); Never (red) Page 13

16 Decimal Places Numbers, Currency The list gives the numbers 0 through 15. The Decimal Places property setting has no effect if the Format property is blank or is set to General Number. Your choice will affect only the number of decimal places that display, not how many decimal places are actually stored. Input Mask Text, Numbers, Date/Time, Currency Input masks allow us to set a template, a pattern that our data must follow. This gives our data a consistent look. Input masks have to be text or date fields. There is an Input Mask Wizard. To launch the wizard, put yourself in the input mask option of your general properties and press the ellipsis ( ) button that will appear at the end of the line. The Input Mask Wizard has several predefined formats for the most common data entry items, such as Phone Number, Socical Security Number and Zip Code. The input mask option appears for Text, Numbers, Date/Time and Currency fields, but the Wizard will only build the mask for Text and Date/Time fields. If you would like to build your own Input Mask such that it will be added to the Wizard you can click on the Edit List button on the first screen of your Wizard. From here you can add in Masks that you may need on a regular basis. Things such as Medical Record Numbers or GatorLink ID's. L for letters; 9 for optional numbers; 0 for required numbers; A for alphanumeric characters Examples: Social Security Number (999) Phone Number US Postal Code 00/00/9900 Date Med Rec # Caption All Field Types Captions replace the field name for the data view of the table, query and form, and are used for the labels on the forms and reports. The caption overrides the field name for all data display purposes. If you need to have the columns shown with the actual field names, you can delete the captions or export the data. Default Value Text, Memo, Number, Date/Time, Currency, Yes/No, Hyperlink The Default Value is the data that is automatically entered into the field when doing your data entry. For example, most of your customers live in Florida, so you may set the default state to FL so you can skip over that column while doing your data entry. Page 14

17 Validation Rule Text, Memo, Number, Date/Time, Currency, Yes/No, Hyperlink Validation Rules limit the values that are entered into this field. Any valid expression can be entered for your rules. Most of the common logic values can be used to create your Validation rules: Logic Value Meaning Examples < Less Than < 25 <1/1/2005 > Greater Than >12 >Now( ) <> Not Equal <>0 <> "Monday" = Equal Used combinatorial with other validation. And Combinational And >12 And <32 >#1/1/05 And <#2/1/05# Or Combinational Or ="M" or ="F" ="FL" or ="GA" Is Null Can be left blank Used combinatorial with other validation. Is Not Null Cannot be left blank Used combinatorial with other validation. Like Used for non exact values Use? to represent one Char Use * to represent many Like "A????" (Field must have five characters and start with the letter "A".) Like "FL*" Not Negates the Logic Values Not =0 Not Like "P*" Validation Text Text, Memo, Number, Date/Time, Currency, Yes/No, Hyperlink Validation Text is the error message that will be displayed when your data does not match the Validation Rule Property. You have 255 characters for your error message. Example: Field Gender, Validation Rule ="M" Or ="F" Without Validation Text: With Validation Text ("Please Enter M for Male and F for Female"): Page 15

18 Required Text, Memo, Number, Date/Time, Currency, OLE Object, Hyperlink, Attachment This option asks if data is required to be entered into the field. If you mark this property Yes, the record cannot be saved without an entry, but Access will allow an entry such as a space. Allow Zero Length Text, Memo, Hyperlink This property is similar to the Required field, however it will not allow you to leave the field with spaces, this property forces you to actually enter data into the field. Indexed Indexed Text, Memo, Number, Date/Time, Currency, AutoNumber, Yes/No, Hyperlink An index speeds up searches and sorting on a field, but may slow updates. There are three choices for indexing your data: No, Yes Allow Duplicates, Yes No Duplicates. The Yes No Duplicates option is automatically used for Primary keys, and will prohibit duplicate values in the field. Indexes are most useful in very large databases, when searching, filtering and sorting the data may be time consuming. For the databases you will build, you probably should not index beyond the primary key fields. Unicode Compression Unicode Compression Text, Memo, Hyperlink Beginning with Access 2000, Microsoft changed the way Access saved text type data fields. In Access 97 and earlier each character represented one byte, under the new Unicode Character Encoding Scheme, each character represents two bytes, thus new versions of Access now require more storage space. Unicode Compression is automatically set to Yes to compress the data as it's saved. The data is automatically uncompressed as it's accessed. For more information on Unicode compression, see the Access Help File. IME Mode IME Mode Text, Memo, Date/Time, Hyperlink The Input Method Editor (IME) allows users to enter and edit Chinese, Japanese, and Korean characters. The IME Mode Property allows you to set one of the following controls. Setting Description Setting Description No Control Kanji Conversion Mode not set (default). Half pitch Katakana Sets half pitch katakana. On Turns on Kanji Conversion Mode. Full pitch Alpha/Num Sets full pitch letters/numbers. Off Turns off Kanji Conversion Mode. Half pitch Alpha/Num Sets half pitch letters/numbers. Disable Disables Kanji Conversion Mode. HangulFull Sets full pitch hangul. Hiragana Sets full pitch hiragana Hangul Sets half pitch hangul. Page 16

19 IME Sentence Mode Text, Memo, Date/Time, Hyperlink As with the IME Mode, this option is for use of Chinese, Japanese, and Korean characters. Smart Tags Text, Memo, Number, Date/Time, Currency, AutoNumber, Hyperlink, Calculated Smart Tags are intended to help you save time in your normal operations. For example, one of the smart tags available is when a person's name in entered, you can send them an . Text Format Memo A memo field can be set to have Rich Text Formats. That means that you can change font formats and use bullets inside a memo field if you set this field property to Rich Text. Text Align Text, Memo, Number, Date/Time, Currency, AutoNumber, Yes/No, OLE, Hyperlink, Calculated This property allows you to set the text alignment. By default text appears on the left of the cell, numbers and dates on the right. This property allows you to set your own horizontal alignment. Show Date Picker Date/Time The default for this value is always with dates, so there is a little calendar that appears at the end of any Date/Time field. The calendar is not helpful with older dates (such as birthdays) nor with times. If you set this value to Never, it will remove the calendar. Append Only Memo, Hyperlink This property tracks the field update history. You can view the history of an Append Only field by right clicking a value in the field, and then clicking Show column history on the shortcut menu. Access displays a history of changes to the field value. Page 17

20 Workshop Exercise 1. If necessary download the database a Open the database 2 AccessTables.accdb 3. Open table Patients a. Adjust Datasheet view - Auto Adjust Address Field 1. View Wilma West Address not fitting Med Rec: Collapse Navigation Pane (F11) 3. Select all AutoFit b. Set properties in Design view - Field sizes 1. State 2 characters 2. Gender 1 character 3. Zip Long Integer 4. View Datasheet - Formatting 1. Capitalize Last Name( > ) View datasheet Remove Caps 2. Capitalize State and Gender ( > ) 3. Format Birthday (mm/dd/yyyy) - Input Mask 1. Zip Code Change to Data Type: Text Try Input Mask again 00000\ 9999;;_ 2. Phone # (999) Birth Date 99/99/ Caption 1. Pt Med Rec Med Rec 2. Pt Last Name Last Name 3. Pt First Name First Name 4. Pt Address Address 5. Pt City City 6. Page 18

21 - Default Value 1. State: FL 2. Create Date: Date( ) Hide Create Date Column in Datasheet view - Validation Rule 1. Gender ="M" or ="F" Set Error Message 2. Birth Date < Date( ) Set Error Message c. Datasheet View - Select All Auto Adjust - Add yourself as a record 1. Move in with Harley Ctrl ' to repeat above cell 4. Open the Visits table a. Sort Table by different fields - Reasons should be in their own table - Doctors should be in their own table b. Close, don't save 5. From the Database Tools Tab Analyze Table a. Analyze Table Visits b. Let me decide c. Rename Table 1 Visit Info - Add Key d. Create 3 Tables - See Page 6 in this packet 1. Visit Info (ID, Pt Med Rec, Visit Date, Visit Time, Visit Length) 2. Visit Reasons (ID, Visit Reasons) 3. Doctors (ID, Doctor Last Name, Doctor First Name, Doctor Ext) e. Fix Heart Burn error, leave Twisted Ankle f. Say OK to horizontal tiling error Page 19

22 6. View new tables a. Add Headache to Reasons - Make sure to leave the row so the record saves (no pencil!) b. Change reason in the first visit to be a Headache - If necessary, Refresh on the Home tab to be able to see Headache on list 7. Right click on one of the tab names and Close All 8. Delete original Visits Table 9. Visit Info Table a. Delete a record - Notice it does not re number - Hide ID column b. Create a Lookup Field for Patient in Visits table - Med Rec #, Last Name, Birth Date c. Add a record to Visits - Ctrl ; for current date - Ctrl : for current time 10. View Relationships (Tools Tab) a. Double click on relationship between Visit Info and Patients - Enforce Referential Integrity 11. Copy Patient Table, Paste as Employee Table (Structure Only) a. Design view - Delete everything but the name fields - Rename fields for Emp First & Emp Last - Set Emp Last as the Primary Key b. Datasheet View - Enter three names 1. Bob Smith, Bob Jones, Mary Jones Press Esc to cancel Mary's Record c. Design View - Set Last and First as a dual Primary Key d. Datasheet View - Add Mary Jones - Add Mary Jones again 1. Press Esc to cancel the record Page 20

23 e. Design View - Create Fields 1. Emp Birthday Date/Time 2. Emp Celebrate Yes/No 3. Emp Hours Worked Number 4. Emp Hourly Rate Currency 5. Emp Picture Attachment f. Datasheet view - Create fake data for employees 1. Double click on paperclip to add the attachment 12. Create a Form from Employees a. Turn to the Form View b. While the Employee Table is open, but all records are saved (no pencil!) c. Click on the FORM button on the Create Tab d. Add a new employee to the form - Add two attachments to the new record - Use arrows to move between the pictures 13. Close and Save Form a. Notice new record not showing b. On Home Tab Refresh Data 14. Exit Access a. Yes it's ok to empty the clipboard 15. If desired, you can the file to yourself a. Open Access b. From the File menu, Info section, Choose Compact and Repair c. Exit Access d. Right click on the file, Send To, Compressed Zipped Folder e. Open Internet browser, go to any online access and attach the zipped folder Page 21