17 January, 2011harshana-fernando.blogspot.com1 Microsoft Office Access VBA.

17 January, 2011 harshana-fernando.blogspot.com 1

Microsoft Office Access

VBA


Before run macros

Under the Ribbon, click the Options button

In the Microsoft Office Security Options

Click the Enabled radio button



On the Ribbon, click Database Tools

Click the Visual Basic button




Introducing Objects

Digital Camera Object

Property Name Property Value

Name Digital Camera

External Color Black

Unit Price 899.95




Programmatically Accessing the Properties of an Object

Private Sub cmdHide_Click() boxRectangle.Visible = False End Sub


With the Properties of an Object

Private Sub cmdManipulate_Click() boxEnvelop.BackStyle = 1boxEnvelop.BackColor = 979478 boxEnvelop.SpecialEffect = 1 boxEnvelop.BorderColor = 234657 boxEnvelop.BorderWidth = 2 End Sub


With ObjectName Statements

End With Private Sub cmdManipulate_Click() With boxEnvelop

.BackStyle = 1 .BackColor = 979478 .SpecialEffect = 1 .BorderColor = 234657

.BorderWidth = 2 End With End Sub


Events



VariablesData type Description Range

Byte 1-byte binary data 0 to 255

Integer 2-byte integer – 32,768 to 32,767

Long 4-byte integer – 2,147,483,648 to 2,147,483,647

Single 4-byte floating-point number

– 3.402823E38 to – 1.401298E – 45 (negative values)

1.401298E – 45 to 3.402823E38 (positive values)

Double 8-byte floating-point number

– 1.79769313486231E308 to– 4.94065645841247E – 324 (negative values)

4.94065645841247E – 324 to 1.79769313486231E308 (positive values)

Currency8-byte number with fixed decimal

point– 922,337,203,685,477.5808 to

922,337,203,685,477.5807

String String of characters Zero to approximately two billion characters

Date 8-byte date/time value January 1, 100 to December 31, 9999


Dim VariableName As DataType

Dim Variable1 As DataType1 Dim Variable2 As DataType2 Dim Variable3 As DataType3

Private Sub Detail_Click() Dim EmployeeIsFullTime As Boolean Dim FullName As String Dim EmploymentStatus As Byte Dim YearHired As Integer Dim DaysOnJob As Long Dim SickTime As Single Dim WeeklyTime As Double Dim HourlySalary As Currency Dim DateHired As Date End Sub


Private Sub Detail_Click() SomeColor = vbRed Detail.BackColor = SomeColor End Sub

• Return to Microsoft Access and display the form in Form View

• Click the form and notice that it appears red


Color Name Constant Value Color

Black vbBlack &h00

Red vbRed &hFF

Green vbGreen &hFF00

Yellow vbYellow &hFFFF

Blue vbBlue &hFF0000

Magenta vbMagenta &hFF00FF

Cyan vbCyan &hFFFF00

White vbWhite &hFFFFFF


Operators

Assignment Operator = Comma , Colon Operator : Double Quotes "" String Concatenator & Negation Operator – Addition + Subtraction - Multiplication *


Operators

Integer Division \ Division / Exponentiation ^ Remainder Operator Mod Comments '


Assignment Operator =

The assignment operation is used to make a copy of a value, an expression, or the content of a control and give the copy to another field or expression.

=FirstName

Private Sub Form_Load() Dim NumberOfTracks As Integer NumberOfTracks = 16 End Sub

Private Sub txtFirstName_LostFocus() txtFullName = txtFirstName End Sub


Comma ,

The comma is used to separate variables used in a group

Sub Exercise() Dim FirstName As String, LastName As String, FullName As StringEnd Sub


Colon Operator :

The Visual Basic language allows you to write as many statements as necessary on the same line.

Sub Exercise() Dim FirstName As String, LastName As String FirstName = "Arsène" LastName = "Nkoulou“End Sub

Sub Exercise() Dim FirstName As String, LastName As String FirstName = "Arsène" : LastName = "Nkoulou" End Sub


Double Quotes: ""

Double-quotes are used to display a string.

= "Manchester United"

Private Sub Form_Load() Dim Address As String Address = "12404 Lockwood Drive Apt D4" End Sub

Private Sub cmdReset_Click() txtFirstName = "" txtMI = "" txtLastName = "" txtFullName = "" txtUsername = "" End Sub


String Concatenator: &

The & operator is used to append two strings, the contents of two controls, or expressions; this is considered as concatenating them.

Value1 & Value2 Private Sub Form_Load() Dim FirstName, LastName As String Dim FullName As String FirstName = "Francis " LastName = "Pottelson" FullName = FirstName & LastName Text0 = FullName End Sub

=Value1 & " " & Value2


Negation Operator -

A variable or an expression can also be represented as negative by prefixing it with a - sign.

Private Sub Form_Load() Dim NumberOfTracks As Byte Dim Temperature As Integer NumberOfTracks = 16 Temperature = -94 End Sub


Addition: +

The addition is used to add one value or expression to another.

Value1 + Value2

= Value1 + Value2

Private Sub cmdSqCalculate_Click() Dim dblSide As Double Dim dblPerimeter As Double dblSide = txtSqSide dblPerimeter = dblSide + dblSide + dblSide + dblSide txtSqPerimeter = dblPerimeter End Sub


Subtraction: -

The subtraction is performed by retrieving one value from another value.

Value1 - Value2

= Value1 - Value2


Multiplication: *

The multiplication allows adding one value to itself a certain number of times, set by the second value.

Value1 * Value2

= Value1 * Value2


Example 1


Example 2


Integer Division: \

Dividing an item means cutting it in pieces or fractions of a set value. For example, when you cut an apple in the middle, you are dividing it in 2 pieces. If you cut each one of the resulting pieces, you will get 4 pieces or fractions.

Value1 \ Value2

= Value1 \ Value2


The Division: /

The second type of division results in a decimal number.

Value1 / Value2

= Value1 / Value2


Exponentiation: ^

Exponentiation is the ability to raise a number to the power of another number.

yx In Microsoft Visual Basic y^x

Total = y^x


Remainder Operator: Mod

The division operation gives a result of a number with or without decimal values, which is fine in some circumstances. Sometimes you will want to get the value remaining after a division renders a natural result.

The remainder operation is performed with keyword Mod. Its syntax is:

Value1 Mod Value2

= Value1 Mod Value2


Comments

A comment is a piece of text in a code section that thedatabase engine would not consider when reading your code.

Private Sub Form_Load() ' This line will not be considered as part of the codeEnd Sub


What is SQL?

SQL is Structured Query Language

What is SQL for?

SQL is used to interact with your database's data


SQL contains a number of keywords such asSELECT, DELETE, UPDATE, FROM, WHERE, OR, AND, DISTINCT and many others….


The Structure of an SQL StatementThis illustration shows the principal parts of a typical SQL query statement:


Whenever a field is specified you have the option to append the table name, separating the two with a dot

SELECT Firstname, Lastname FROM tblStaff ORDER BY Lastname

is the same as: SELECT tblStaff.Firstname, tblStaff.Lastname FROM tblStaff ORDER BY tblStaff.Lastname

If your query refers to more than one table you must include the table name along with the field name.


Data Type Qualifiers

Text must be enclosed in either single quotes (') or double quotes (")

WHERE tblStaff.Department = "Marketing” Date should be enclosed in hash marks (#) WHERE tblStaff.BirthDate = #09/27/1950#

Number, of any sort, needs no qualifier and can be entered as it is

WHERE tblInvoices.InvoiceNumber > 1500


How to Write SQL in VBA

Dim strSQL As StringstrSQL = "... THE SQL STATEMENT GOES HERE ...”DoCmd.RunSQL strSQL

Also

DoCmd.RunSQL "... THE SQL STATEMENT GOES HERE ...”


Write SQL Keywords in Upper Case

Access doesn't care if you do this or not but you will find your code much easier to read and understand if you do

Select tblStaff.Firstname, tblStaff.Lastname from tblStaff where tblStaff.Office="Paris”;

SELECT tblStaff.Firstname, tblStaff.Lastname FROM tblStaff WHERE tblStaff.Office="Paris”;


Enclose Field Names in Square Brackets

Always put square brackets around field names. Access only demands that you do this when your field names contain spaces. For example, FirstName is OK but in your code First Name must be written [First Name]. The brackets tell Access that all the words in the field name belong together.

SELECT tblStaff.[Firstname], tblStaff.[Lastname]

FROM tblStaff

WHERE tblStaff.[Office]="Paris”;


Write Each Clause on a Separate Line

SELECT tblStaff.* FROM tblStaff;

SELECT tblStaff.[Firstname], tblStaff.[Lastname] FROM tblStaff WHERE tblStaff.[Office]="Paris”;


Alternate Single and Double Quotes


Working with Variables


Using DoCmd.RunSQL to Run Action Queries

• Build a New Table

DoCmd.RunSQL "CREATE TABLE tblTest ([StaffID] COUNTER CONSTRAINT ndxStaffID PRIMARY KEY, [FirstName] TEXT(25), [LastName] TEXT(30), [BirthDate] DATETIME);"

Enter the line of code as a single line into the Immediate Window, then press Enter

Open the Immediate Window by pressing Ctrl+G. In Access 2000/2002 the Immediate Window will appear, usually docked to the lower edge of the Visual Basic Editor window


• Add Records to a Table

DoCmd.RunSQL "INSERT INTO tblTest ([FirstName], [LastName], [BirthDate]) VALUES ('Martin', 'Green', #09/27/1950#);"

Access displays a message asking permission to add a record to the table.



• Add a Field to a Table

DoCmd.RunSQL "ALTER TABLE tblTest ADD COLUMN [Age] BYTE;"



• Modify Existing Records

DoCmd.RunSQL "UPDATE tblTest SET [Age]=52 WHERE [FirstName]='Martin' AND [LastName]='Green';"


• Delete a Table

DoCmd.RunSQL "DROP TABLE tblTest;"


You won't see any warning message, but you will find that the table has gone

Date post:	21-Jan-2016
Category:	Documents
Upload:	sharon-wilkins
View:	217 times
Download:	3 times

17 January, 2011harshana-fernando.blogspot.com1 Microsoft Office Access VBA.

Documents