Need to change SQL query in android studio database to return multiple results

Question

I have a functioning database within my android app that returns one result queries. I am trying to return multiple results for a Wine keyword but every time I try the app crashes when i run it. I am fairly new to android coding so I could be missing something obvious.

The first .java is the search function. The second one is the query activity.

package com.example.winedatabase;

import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class DatabaseAccess {
    private SQLiteOpenHelper openHelper;
    private SQLiteDatabase db;
    private static DatabaseAccess instance;
    Cursor c = null;

    //private constructor so that object creation from outside is avoided
    private DatabaseAccess(Context context){
        this.openHelper = new DatabaseOpenHelper(context);

    }

    //to return the single instance of database
    public static DatabaseAccess getInstance(Context context){
        if(instance == null){
            instance= new DatabaseAccess(context);

        }
        return instance;
    }

    //to open the database
    public void open(){
        this.db = openHelper.getWritableDatabase();
    }
    //closing the database connection
    public void close(){
        if (db != null) {
            this.db.close();
        }
    }
    //method to query and return the result from the database
    public String getKeyword(String winename){
        c = db.rawQuery(" select WineName from Wine where WineName LIKE %'"+winename+"'%", new String[]{});
        StringBuffer buffer = new StringBuffer();
        while(c.moveToNext()){
            String description = c.getString(0);
            buffer.append(""+description);
        }
        return buffer.toString();
    }

}

package com.example.winedatabase;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class KeywordSearch extends AppCompatActivity {

    public EditText name;
    public Button query_button;
    public TextView result_address;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_keyword_search);

        name = findViewById(R.id.name);
        query_button = findViewById(R.id.query_button);
        result_address = findViewById(R.id.result);

        //set onClickListnener to query button

        query_button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //create the instance of database access class and open database connection

                DatabaseAccess databaseAccess = DatabaseAccess.getInstance(getApplicationContext());
                databaseAccess.open();

                //get string value of edittext

                String n = name.getText().toString();
                String description = databaseAccess.getKeyword(n);  //used the get address method to get address

                //set text to result field
                result_address.setText(description);
                databaseAccess.close();
                //database connection closed

            }
        });
    }
}

Answer 1

Your query is syntactically wrong. The wildcard % and the parameter winename should be enclosed inside single quotes, but also it is recommended and safer to pass the parameter winename in the 2nd argument of rawQuery().
Change to this:

c = db.rawQuery(
    "select WineName from Wine where WineName LIKE '%' || ? || '%'", 
    new String[]{winename}
);