Pass data to another class

I have two tables,one is Information and another is WorkDetailsTable. The flow of activity is Information.java>>WorkDetailsTable.java by intent. When button in Information.java has clicked, it will save all the data and pass to WorkDetails.java.

Information.java

 Button button=(Button)findViewById(R.id.button5);

       button.setOnClickListener(new View.OnClickListener() {
            public void onClick(View arg0) {
                Intent intent = new Intent(context, WorkDetailsTable.class);
                intent.putExtra("a",a);
                intent.putExtra("b",b);
                intent.putExtra("date1",date1);
                intent.putExtra("c",c);

                startActivity(intent);
            }
        });

WorkDetailsTable

public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
final String name=getIntent().getExtras().getString("a"); // data get from Information.java
final String weather=getIntent().getExtras().getString("b");
final String date=getIntent().getExtras().getString("date1");
final String status=getIntent().getExtras().getString("c");
ts= new com.example.project.project.API.InfoAPI(this);
WD= new com.example.project.project.API.WorkDetailsAPI(this);
Button btn1=(Button)findViewById(R.id.button2);
       btn1.setOnClickListener(new View.OnClickListener() {
             public void onClick(View arg0) {
                    W1=txtWork1.getText().toString();
                    W2=txtWork2.getText().toString();
                    W3=txtWork3.getText().toString();
                    W4=txtWork4.getText().toString();
                    P1=per1.getText().toString();
                    P2=per2.getText().toString();
                    P3=per3.getText().toString();
                    P4=per4.getText().toString();
                    ts.insertTimeSheet(name,weather,date,status); 
//insert multiple row to Work Details table, Id auto increment but foreign key remains the same
                    WD.insertWorkDetails(a1,W1,P1,b,c,th);
                    WD.insertWorkDetails(a2,W2,P2,d,e1,th);
                    WD.insertWorkDetails(a3, W3, P3, f, g,th);
                    WD.insertWorkDetails(a4,W4,P4,h,i,th);
                }
            });
        }

InfoAPI.java

public String[] allColumns={MyDatabaseHelper.ID,MyDatabaseHelper.Name,MyDatabaseHelper.Weather,MyDatabaseHelper.Date,MyDatabaseHelper.Status};
 public long insertTimeSheet(String name,String weather,String date,String status)
    {
        database=dbHelper.getWritableDatabase();
        ContentValues values=new ContentValues();
        values.put(MyDatabaseHelper.Name,name);
        values.put(MyDatabaseHelper.Weather,weather);
        values.put(MyDatabaseHelper.Date,date);
        values.put(MyDatabaseHelper.Status,status);
        database.insert(MyDatabaseHelper.TABLE_INFO,null,values);
        database.close();
        return 0 ;

    }

WorkDetailsAPI.java

     public String[] allColumns={MyDatabaseHelper.ID2,MyDatabaseHelper.Project,MyDatabaseHelper.WorkDescription,MyDatabaseHelper.Per,MyDatabaseHelper.TimeIn,MyDatabaseHelper.TimeOut,MyDatabaseHelper.TotalHours,MyDatabaseHelper.TableInfo_id};
 public long insertWorkDetails(String project, String workDescription, String per,String timeIn,String timeOut,String totalHours)
    {
        database=dbHelper.getWritableDatabase();
        ContentValues values=new ContentValues();
        values.put(MyDatabaseHelper.Project,project);
        values.put(MyDatabaseHelper.WorkDescription,workDescription);
        values.put(MyDatabaseHelper.Per,per);
        values.put(MyDatabaseHelper.TimeIn,timeIn);
        values.put(MyDatabaseHelper.TimeOut,timeOut);
        values.put(MyDatabaseHelper.TotalHours,totalHours);
        database.insert(MyDatabaseHelper.TABLE_WORKDETAILS,null,values);
        database.close();
        return 0 ;

    }

MyDatabaseHelper.java

 public void onCreate(SQLiteDatabase db)
    {
        db.execSQL("create table "+TABLE_INFO+"(ID INTEGER PRIMARY KEY ,Name TEXT,Weather TEXT, Date DATETIME, Status Text)");
        db.execSQL("create table"+TABLE_WORKDETAILS+"(ID INTEGER PRIMARY KEY , Project TEXT, WorkDescription TEXT, Per Text, TimeIn DATETIME, TimeOut DATETIME,TotalHours DATETIME, TableInfo_id INTEGER, FOREIGN KEY(TableInfo_id)REFERENCES TABLE_INFO(ID)");
    }

To make my question more understandable, I have summarized it as below:

1. Is this the correct way to pass the data to another class and save them to different table ?
2. How to insert a foreign key into another table?

I have asked a similar question which related to my problem. Kindly refer Inserting a foreign key into a table

When I run my project, it comes out with errors.

10-02 04:56:29.104    5016-5030/com.example.project.project E/Surface﹕ getSlotFromBufferLocked: unknown buffer: 0xb4057be0
10-02 04:56:29.107    5016-5030/com.example.project.project D/OpenGLRenderer﹕ endAllStagingAnimators on 0xa2d54000 (RippleDrawable) with handle 0xabe46820
10-02 04:56:34.936    5016-5016/com.example.project.project E/SQLiteLog﹕ (1) near "tableWork": syntax error
10-02 04:56:34.974    5016-5016/com.example.project.project D/AndroidRuntime﹕ Shutting down VM
10-02 04:56:34.974    5016-5016/com.example.project.project E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: com.example.project.project, PID: 5016
    android.database.sqlite.SQLiteException: near "tableWork": syntax error (code 1): , while compiling: create tableWork Details(ID INTEGER PRIMARY KEY , Project TEXT, WorkDescription TEXT, Per Text, TimeIn DATETIME, TimeOut DATETIME,TotalHours DATETIME, TableInfo_id INTEGER, FOREIGN KEY(TableInfo_id)REFERENCES TABLE_INFO(ID)
            at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
            at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:887)

回答1:

The problem is in your create query, the second one.

db.execSQL("create table"+TABLE_WORKDETAILS+"(ID INTEGER PRIMARY KEY , Project TEXT, WorkDescription TEXT, Per Text, TimeIn DATETIME, TimeOut DATETIME,TotalHours DATETIME, TableInfo_id INTEGER, FOREIGN KEY(TableInfo_id)REFERENCES TABLE_INFO(ID)");

You logs show that this is the query which is executed:

android.database.sqlite.SQLiteException: near "tableWork": syntax error (code 1): , while compiling: create tableWork Details(ID INTEGER PRIMARY KEY , Project TEXT, WorkDescription TEXT, Per Text, TimeIn DATETIME, TimeOut DATETIME,TotalHours DATETIME, TableInfo_id INTEGER, FOREIGN KEY(TableInfo_id)REFERENCES TABLE_INFO(ID)

Firstly, you missed the space after table. Secondly, your constant TABLE_WORKDETAILS value is Work Details. The table name should not have spaces, so change it to Work_Details. You should also give space after FOREIGN KEY(TableInfo_id).

It should be like this:

 db.execSQL("create table "+TABLE_WORKDETAILS+"(ID INTEGER PRIMARY KEY , Project TEXT, WorkDescription TEXT, Per Text, TimeIn DATETIME, TimeOut DATETIME,TotalHours DATETIME, TableInfo_id INTEGER, FOREIGN KEY(TableInfo_id) REFERENCES "+TABLE_INFO+"(ID))");

回答2:

The error you are getting is because the SQL sentence you are using is incorrect:

db.execSQL("create table"+TABLE_WORKDETAILS+"(ID INTEGER PRIMARY KEY , Project TEXT, WorkDescription TEXT, Per Text, TimeIn DATETIME, TimeOut DATETIME,TotalHours DATETIME, TableInfo_id INTEGER, FOREIGN KEY(TableInfo_id)REFERENCES TABLE_INFO(ID)");

Here after the word table you are missing a blank space, also you are missing a parenthesis at the end of the sentence.

It should be like this:

db.execSQL("create table "+TABLE_WORKDETAILS+"(ID INTEGER PRIMARY KEY , Project TEXT, WorkDescription TEXT, Per Text, TimeIn DATETIME, TimeOut DATETIME,TotalHours DATETIME, TableInfo_id INTEGER, FOREIGN KEY(TableInfo_id)REFERENCES TABLE_INFO(ID))");

I think that the foreign key syntax is correct but be aware that foreign keys restrictions are disables by default, if you want to enable them you have to use PRAGMA foreign_keys = ON sentence.

Finally your variable TABLE_WORKDETAILS should have no blank spaces as table names cannot have them so change it to Work_Details Hope it helps

回答3:

To avoid such time consuming and error prone low level sql-issues, you could consider using an sql-lite ORM (Object-Relational Mapping) library, which handles the persistance of your objects (and therefore the creation of sql statements) for you.

To get an overview, take a look here, here or here