Android Question Problem with Connecting Android to MySQL Database

[Shubhankar]

I refer to the Mysql tutorial

In the tutorial a two line custom type is used

If I want to get more than 2 responses form the server do I still use twolines as a custom type?
I tried using five lines but it doesnt work
Is there a generic type i can use for multiple return values

 

[Erel]

The two lines type is only used in the example to store the ListView data.

You can keep the original list returned from Parser.NextArray. It holds all the data from the server.

 

[Shubhankar]

I dont really understand
I am using your example and wish to have more than 2 values
I quote from your comments in the example
"We are using a custom type named TwoLines (declared in Sub Globals).
'It allows us to later get the two values when the user presses on an item."

so what shld i declare instead of two lines ?

 

[Erel]

What do you want to do with the data?

 

[Shubhankar]

I want my list generated to have 5 different sets of data instead of 2 'per country'

 

[KMatle]

I want my list generated to have 5 different sets of data instead of 2 'per country'

It's always good to post an example...

You need to add more rows/culumns to you table. Please notice that there will be ONE request and ONE result at a time, not two. It's up to you to return the data as you need by modifiying the request.

It's like an order in a restaurant. You get what you order.

 

[Shubhankar]

Under sub Job done I have this part written
Dim tl As TwoLines
tl.First = m.Get("id")
tl.Second = m.Get("course_name")
' tl.course_desc=m.Get("course_desc")
' tl.course_days= m.Get("course_days")
' tl.course_rating= m.Get("course_rating")

The programme only works if I comment off the last 3. I feel the problem is with the Twolines part. Hope you can help

 

[Shubhankar]

Decided to put my example up
Also when I run the programme and click on my list I get an error saying
" error in sub:main_jobdone(java line 477)
java.lang.NumberFormatException:Invalid double:"null"

 

[Erel]

What is the output of Log(m)?

 

[Shubhankar]

Managed to fix the initial problem of showing more than one entry but now I am unable to display the database info upon clicking
i get an error saying from job done saying object should be initialised first (label)
Thanks for ur help @Erel

 

[Erel]

Please post the error message from the logs.

 

[Shubhankar]

Here you go

 

[Shubhankar]

@Erel I am uploading my updated code as well

 

[Erel]

See all the warnings:

Once you fix them it will work.

The label course is never initialized. I guess that you forgot to load one of the layout files.

 

[Shubhankar]

hey @Erel

i am still having problems. i already initialised all the members. The issue i am having is upon clicking. I want to create something along these lines. When I open the app i see the list ( which is obtained from the database) then when i click it opens coursesv3 and gets the data from the database again. I made a activity module so i can choose options and go back to the list. However in the activitity module my tl is unrecognised despite initialising it. Also i am unsure if the module is able to retrieve the value through Main.tl.course_desc. Or should i place it like this Main.jobdone.tl.course_desc?

Hope you understand and can help
Thanks!!

 

[Erel]

There are many warnings and errors in your code.

I recommend you to start with the beginner's guide: https://www.b4x.com/android/documentation.html

 

[Shubhankar]

Hey @Erel
Solved all the errors
having an error now on line 38 in the open folder activity . I am unable to refer to the function from the main.

Also the initial problem still persists. (the problem in job done)

 

[Erel]

1. Please post the error as text (right click to copy).
2. What is line 38?
3. What is the output of Log(m) ?

 

[Shubhankar]

Logs are only available in debug mode when connected with B4A-Bridge.
LogCat connected to: B4A-Bridge: samsung GT-P5113
--------- beginning of /dev/log/system
--------- beginning of /dev/log/main
** Activity (main) Resume **
** Activity (main) Pause, UserClosed = false **
** Activity (main) Create, isFirst = false **
** Activity (main) Resume **
Response from server: [{"id":"1","course_name":"Basic Excel 2013","course_desc":"Learn basic to intermediate functions of Excel. Simple formulas and features of Microsoft Excel 2013","course_days":"2 Days.","course_rating":"4.68"},{"id":"2","course_name":"Advanced Excel 2013","course_desc":"Learn Pivot Tables, VLookup, Macros & Advanced Functions of Excel.","course_days":"2 Days.","course_rating":"4.87"},{"id":"3","course_name":"Introduction to SQL","course_desc":"Learn to create a SQL database, query a database table and select, insert, update & delete records.","course_days":"2 Days.","course_rating":"4.89"},{"id":"4","course_name":"Facebook Marketing for Business","course_desc":"Learn to use Facebook for marketing your business on your own.","course_days":"1 Day","course_rating":"4.79"}]
** Activity (main) Pause, UserClosed = false **
** Activity (main) Create, isFirst = false **
** Activity (main) Resume **
Response from server: [{"id":"1","course_name":"Basic Excel 2013","course_desc":"Learn basic to intermediate functions of Excel. Simple formulas and features of Microsoft Excel 2013","course_days":"2 Days.","course_rating":"4.68"},{"id":"2","course_name":"Advanced Excel 2013","course_desc":"Learn Pivot Tables, VLookup, Macros & Advanced Functions of Excel.","course_days":"2 Days.","course_rating":"4.87"},{"id":"3","course_name":"Introduction to SQL","course_desc":"Learn to create a SQL database, query a database table and select, insert, update & delete records.","course_days":"2 Days.","course_rating":"4.89"},{"id":"4","course_name":"Facebook Marketing for Business","course_desc":"Learn to use Facebook for marketing your business on your own.","course_days":"1 Day","course_rating":"4.79"}]
** Activity (main) Pause, UserClosed = false **
** Activity (openfolder) Resume **
** Activity (openfolder) Pause, UserClosed = false **
** Activity (main) Resume **
Response from server: [{"id":"4","course_name":"Facebook Marketing for Business","course_desc":"Learn to use Facebook for marketing your business on your own.","course_days":"1 Day","course_rating":"4.79","course_prereq":"Must know basic PC skills, and must have a Facebook account.","course_outcomes":"Learn to use Facebook for business use. Understanding Posting, Events, Groups, Pages and make the best use of the most popular Social Media Marketing application.","course_comments":"","course_grant":"SDF, PIC & SkillsFuture"}]
main_jobdone (java line: 536)
java.lang.NumberFormatException: Invalid double: "null"
at java.lang.StringToReal.invalidReal(StringToReal.java:63)
at java.lang.StringToReal.parseDouble(StringToReal.java:269)
at java.lang.Double.parseDouble(Double.java:295)
at anywheresoftware.b4a.BA.ObjectToNumber(BA.java:612)
at anywheresoftware.b4a.samples.mysql.main._jobdone(main.java:536)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:169)
at anywheresoftware.b4a.keywords.Common$5.run(Common.java:996)
at android.os.Handler.handleCallback(Handler.java:605)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4514)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:790)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:557)
at dalvik.system.NativeStart.main(Native Method)
java.lang.NumberFormatException: Invalid double: "null"



line 38 is the main.executeremotequery

 

[Shubhankar]

output of log m is the custom list
Not entirely sure i know what you are asking