Indexed files

[bplus]

You want to open a file for Random (Access) and best if you set it with a fixed length record size. This allows you to read and write records to a record number.

Here is a demo for johnno for tracking Blood tests;

Code: (Select All)

'Tutorial (with help from Wiki):

' save this bas file in the folder where you want you BloodData.dat file to go first!

Type Blood
    date As String * 10
    level As Integer
    comment As String * 50
End Type

'Make a record:
Dim Shared Record As Blood, lenRecord&, nRecs&
lenRecord& = Len(Record)

' start up the data file
Open "BloodData.dat" For Random As #1 Len = lenRecord&


Record.date = "2022/11/18"
Record.level = 101
Record.comment = "This is my comment."

'Store a record:
Put #1, 1, Record

nRecs = LOF(1) / lenRecord&
Print "number recs:"; nRecs ' good 1 lets get it

' get record
Get #1, 1, Record
Print Record.date; ":"; Record.level; ", "; Record.comment

' stick another record in there
nRecs = nRecs + 1
Record.date = "2022/11/19"
Record.level = 105
Record.comment = "This is my next comment."
Put #1, nRecs, Record

' check records
nRecs = LOF(1) / lenRecord&
Print "number recs:"; nRecs ' good 1 lets get it

For i = 1 To nRecs
    Get #1, i, Record
    Print Record.date; ":"; Record.level; ", "; Record.comment
Next

You create a data entry form for entering the record to file file or reading records out.