CODEWITHSUNDEEP
javaandroiddatabasesqlite
Brejuro
Brejuro

Reputation: 3541

How to insert my first and subsequent rows into a my database for android project

I have a DatabaseHelper class that builds all my tables and handles queries, etc.

However, one thing stumps me.

I have a checklist table with the following columns:

checklist_id, int, primary key
start_time,   text
end_time,     text

This is my "insertChecklist()" method, that inserts a row into the table:

public long insertChecklist(Checklist checklist){
        // Get reference of the ChecklistDB database
        SQLiteDatabase db = this.getWritableDatabase();

        // Make values to be inserted
        ContentValues values = new ContentValues();
        values.put(ChecklistContract._ID, checklist.getId());
        values.put(ChecklistContract.COLUMN_NAME_START_TIME, checklist.getStartTime());
        values.put(ChecklistContract.COLUMN_NAME_END_TIME, checklist.getEndTime());

        // Insert the new row, returning the primary key value of the new row
        long newRowId;
        newRowId = db.insert(
                ChecklistContract.TABLE_NAME,
                null, //COLUMN_NAME_NULLABLE (set to null to not insert new row where there are no values)
                values);

        // close database transaction
        db.close();

        return newRowId;
    }

So I utilize this function as follows:

  1. I create a Checklist object
  2. I pass it into my insertChecklist() method

However, how do I know what to make the id in my Checklist object? 

Checklist checklist = new Checklist(id??, startTime, endTime); 
// the "id" needs to be the equal to the last id in the table, plus 1

insertChecklist(checklist);

Does anyone have experience with SQLite databases that could help me with this? Am I approaching this wrong?

Upvotes: 0

Views: 46

Answers (1)

CL.
CL.

Reputation: 180020

The insert() function returns the rowid of the new row.

If your table has an autoincrementing ID, i.e., an INTEGER PRIMARY KEY or INTEGER PRIMARY KEY AUTOINCREMENT column, then this is the same as the rowid.

In that case, to automatically assign a new value, do not put any ID value into the ContentValues, and set the ID of your object to the value returned by insert():

public void insertChecklist(Checklist checklist) {
    SQLiteDatabase db = this.getWritableDatabase();
    try {
        ContentValues values = new ContentValues();
        values.put(ChecklistContract.COLUMN_NAME_START_TIME, checklist.getStartTime());
        values.put(ChecklistContract.COLUMN_NAME_END_TIME,   checklist.getEndTime());

        long id;
        id = db.insertOrThrow(ChecklistContract.TABLE_NAME, null, values);
        checklist.setId(id);
    } finally {
        db.close();
    }
}

Upvotes: 1

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