1. Saving and Accessing Data

2. Two general ways to save data
To an established file format, like MS Access or Excel. That is the most common way.
To a file that you define (dat, txt, etc.):
Sequential
Random
Binary

3. File differences Sequential Read/Write the WHOLE file
Random Read/Write any Record
Binary Read/Write any Byte

4. Opening Files Read Write Both Open “theFile.txt” as #1
Now refer to theFile.txt as #1
The # is the “channel” of the file
You can find a FreeFile.

5. You open with the following modes:
Append
Binary
Output
Random
Adds to end of sequential file
Write/Read individual Bytes
Write/Overright sequential file
Write to specific Records
Random is the Default
Open “myFile.txt” for Random as #3

6. Managing Multiple Users
Access Restriction
Write
Read Write
Read
LockType
Shared
Lock Read
Lock Write
Lock Read Write
Open "C:\Random.txt" For Random Access Read Write Shared As #intFile Len = 5
Book is not clear on Access. These are needed when multiple users are involved to maintain file integrity.

7. Length -- Len
Necessary with random files to let the computer know how far to look for the next record.
RECORD – One “line” or set of information. Examples: Each recipe in a cookbook; Each entry in an address book.

8. Input/Output Choices To File From File
Sequential (Append, Input, Output)
Print #
Write #
Read #
Random
Put #
Get #
Put #7, recordNum, Variable

9. Delimeters
Delimeters are characters that indicate the end of a “column” or “field”
A column or field is one variable in a record.
Kevin, Harville, Instructor,
Joe, Jones, Dog Catcher,

10. Record Lengths Kevin Harville Instructor Joe Jones Dog Catcher
Establishing data lengths helps the computer know where to look for the information

11. Data Types Data Types are like a master variable with sub-variables.
Employee.Age
Employee.FirstName
Employee.LastName
Employee.SSN

12. Data Types Declare in Modules Type Employee
strFName As String * 10 strLName As String * 16 strSSN As String * 12
End Type
Dim Worker(100) As Employee
Worker(x).strFName=strInputName
Worker(x).strLName=strInputLName
Worker(x).strSSN=txtSSN.Text

13. File Controls File List Box Drive List Box Directory List Box
You need to program functionality in these or the common dialog box to manually access files

14. File Commands
Chdrive
ChDir
Kill
MkDir
RmDir
Dir

15. Changing
Usual place to responde to changes is in the Change event of the directory, file, or drive controls.
ChDrive drvDisk.Drive
ChDir dirDirect.Path
FilFiles.Pattern= “*.txt; *.htm”