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Android Android Data Persistence CRUD Operations with SQLite Retrieving Data

Posted by Dalton Coble
Dalton Coble
6,489 Points

I am doing this like the challenge had asked, I think.

"Once again, assume you have a variable named database. Now we want to retrieve all rows from the table named "PETS_TABLE". Set the cursor variable using the appropriate method that retrieves data from the table. Hint: Use this method and use null values for everything except the first two parameters."

I have worked on this for an hour and am not sure how my code is wrong. Please Help.

CodeChallenge.java 
String[] columns = { "name", "type", "breed" };

Cursor cursor;
public Cursor query("PETS_TABLE","columns",
                     "null",
                    "null",
                     "null",
                    "null",
                     "null")

2 Answers

Jack Middlebrook
Jack Middlebrook
19,746 Points
Jack Middlebrook
Jack Middlebrook
19,746 Points

The query method needs to be called on an SQLiteDatabase. For this code challenge the prompt says you can assume you have one called database. From the documentation you can see the query method returns a Cursor which you will want to assign to the cursor variable that is created with the line Cursor cursor. You have the correct number of parameters passed to query but for "columns" and "null" you need to leave out the quotes. With these changes it should look like:

String[] columns = { "name", "type", "breed" };

Cursor cursor = database.query("PETS_TABLE", columns, null, null, null, null, null);
Tichaona Mudzuri
Tichaona Mudzuri
6,373 Points
Tichaona Mudzuri
Tichaona Mudzuri
6,373 Points

Thank you.