Android Question loading a csv file in a Map or HashMap

[saeed10051]

Hi All,
i am building an application in which i have a csv file related to data of students in a class, the unique key here is the student roll number, the data include student name, class, section, grade in last year etc.
i want to load this data in my application but if i try to use a Map then there is only a key value pair and if i use a list to load the data in, then i cannot sort for a certain record based on key. can anyone help me in that. I will put my csv file in DirAssets folder so that it goes with application. Is there a way to use HashMap for this purpose.

 

[josejad]

You can follow this sample:

Load CSV into Sqlite

Here is what I am trying to do. Load a csv file into a sqlite database. This database will be used to read/write records to/from. I have found this. Dim su As StringUtils Dim Table As List Table = su.LoadCSV(File.DirAssets, "Trivia.csv", ",") But I can't find the code to actually load the...

www.b4x.com

Not tested, but you can use as key the roll nomber, and as value the list with data

Dim su As StringUtils
Dim Table As List
Table = su.LoadCSV(File.DirAssets, "Trivia.csv", ",")
Dim Items() As String
Dim StudentData as List
For i = 0 To Table.Size - 1
 Items = Table.Get(i)
 StudentData.Initialize2(Items)
 Dim m As Map
 m.Initialize
 m.Put(Items(0), StudentData) '(supposing first item is roll number) 

Next

 

[Erel]

Dim su As StringUtils
Dim Table As List = su.LoadCSV(File.DirAssets, "Trivia.csv", ",")
Dim m As Map
m.Initialize
For Each row() As String In Table
 Dim st As StudentType = CreateStudentType(row)
 m.Put(st.Id, st)
Next


Sub CreateStudentType (Row() As String) As StudentType
 '''
End Sub

 

[William Lancee]

Just in case you are not used to "Type", in Process_Globals add the line below and hover/click on name of type to automatically generate the Sub

Sub Process_Globals
    Type StudentType(Roll as String, Name as String, ...)
End Sub

'change Dim st As StudentType = CreateStudentType(row) to CreateStudentType(row(0), row(1), ...)
'or modify the arguments of the generated sub

Sub CreateStudentType (Roll as String, Name as String, ...) As StudentType
    Dim t1 as StudentType
    t1.Initialize
    t1.Roll = Roll
    t1.Name = Name
    ...
    Return t1
End Sub

 

[saeed10051]

Dim su As StringUtils
Dim Table As List = su.LoadCSV(File.DirAssets, "Trivia.csv", ",")
Dim m As Map
m.Initialize
For Each row() As String In Table
Dim st As StudentType = CreateStudentType(row)
m.Put(st.Id, st)
Next


Sub CreateStudentType (Row() As String) As StudentType
'''
End Sub

Thanks Erel, i need to review the documentation related to Type to fully understand it. Can you suggest any link in B4A documentation.

 

[josejad]

https://www.b4x.com/guides/B4xBasicLanguage/?page=46

You can too simply type "type" in the forum search, and you'll get info on the top of answers.

 

[saeed10051]

Just in case you are not used to "Type", in Process_Globals add the line below and hover/click on name of type to automatically generate the Sub

Sub Process_Globals
    Type StudentType(Roll as String, Name as String, ...)
End Sub

'change Dim st As StudentType = CreateStudentType(row) to CreateStudentType(row(0), row(1), ...)
'or modify the arguments of the generated sub

Sub CreateStudentType (Roll as String, Name as String, ...) As StudentType
    Dim t1 as StudentType
    t1.Initialize
    t1.Roll = Roll
    t1.Name = Name
    ...
    Return t1
End Sub

Hi William thanks for the help, i couldnt get why we are defining rows as row(o), row(1) etc. in the StudentType, i think these are various columns if we visualize it as an excel sheet and the rows will be records of various students. Also please can you guide me to some documentation that fully define this Type thing.

 

[Erel]

Also please can you guide me to some documentation that fully define this Type thing.

Everything is explained in the video tutorials and the programing guides: https://www.b4x.com/etp.html