Question

我目前正在开发一个小应用程序，它允许将人员详细信息存储在数据库中，然后将其检索到EditText字段中。目前我能够将人名存储到数据库中。但我无法检索这些数据。

任何人都可以给予的任何帮助将不胜感激！

谢谢！

DatabaseHelper.java：

 package my.example.com.mymedicare;

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

 public class DatabaseHelper extends SQLiteOpenHelper {
public DatabaseHelper(Context context) {
    super(context, "user.db", null, 4);
}

@Override
public void onCreate(SQLiteDatabase db) {
    db.execSQL("CREATE TABLE Users (ID INTEGER PRIMARY KEY  AUTOINCREMENT  NOT NULL , FullName VARCHAR, Email VARCHAR, Number INTEGER, Age INTEGER, Nurse VARCHAR)");
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    db.execSQL("DROP TABLE IF EXISTS Users");

    // Create tables again
    onCreate(db);

}
 }

SQLHelper.java：

 package my.example.com.mymedicare;

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

 import java.io.File;
 import java.io.InputStream;
 import java.util.ArrayList;
 import java.util.List;

 public class SQLHelper  {
Context mContext;
DatabaseHelper dbHelper;
public SQLHelper(Context mContext) {
    dbHelper = new DatabaseHelper(mContext);
    this.mContext = mContext;
}



public boolean insert(String FullName, int i){
    SQLiteDatabase db = dbHelper.getWritableDatabase();
    ContentValues values = new ContentValues();
    values.put("FullName", FullName);
        db.close();
        return true;
    }
    }

Register.java：

package my.example.com.mymedicare;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;

public class Register extends AppCompatActivity {

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


public void btnCreate(View view) {

    SQLHelper sqlHelper = new SQLHelper(this);

    EditText addName = (EditText) findViewById(R.id.nameText);
    sqlHelper.insert(addName.getText().toString(), 0);

    Toast.makeText(this, "Your Account Details Have Been Saved", Toast.LENGTH_SHORT).show();
    startActivity(new Intent(Register.this, MainMenu.class));
}}

Modify.java：

 package my.example.com.mymedicare;

 import android.database.Cursor;
 import android.database.sqlite.SQLiteDatabase;
 import android.support.v7.app.AppCompatActivity;
 import android.os.Bundle;
 import android.widget.EditText;

 public class Modify extends AppCompatActivity {

static SQLiteDatabase db;

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

    EditText getName=(EditText)findViewById(R.id.nameText);
 }
 }

Answer 1

按照此步骤操作。

将此方法放在SQLHelper.java文件中。

    public ArrayList<String> fetch_Edittext() {
    ArrayList<String> arr_ = new ArrayList<String>();
    String selectQuery = "Select * FROM " + TABLE_SCANITEMS + " ORDER BY id";

    SQLiteDatabase db = this.getWritableDatabase();
    Cursor cursor = db.rawQuery(selectQuery, null);

    if (cursor.moveToFirst()) {
        do {
            arr_.add(cursor.getString(0));

        } while (cursor.moveToNext());
    }
    db.close();
    return arr_;
}

将此类放在修改java类

中

private class GetEdittext extends AsyncTask<Void, Void, Void> {
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        // dialog start
        Log.e("Currency", "3");
    }

    @Override
    protected Void doInBackground(Void... arg0) {
        ArrayList<String> arr_ = new ArrayList<String>();
        arr_ = db.fetch_Edittext();
        return null;
    }

    @Override
    protected void onPostExecute(Void resul) {
        super.onPostExecute(resul);
        // dialog dismiss
        //hear set your edit text
    }
}

然后在创建方法上调用此类，如。

new GetEdittext().execute();

从SQL Lite数据库中将数据检索到EditText

1 个答案: