如何在Android中连接Sqlite数据库 [英] How Do I Get Connect The Sqlite Databse In Android

问题描述

您好先生



实际上我需要您的帮助来开发与其中的数据库交互的Android应用程序。所以，请您提供最简单的代码来存储和检索来自数据库。并告诉我它需要什么先决条件，如Odbc或任何东西。

最后我想知道，如果我们通过提供数据库开发任何静态应用程序（如在线考试的应用程序和其中我们将提供一些问题）因为我提到它是离线的，所以如果我想要更改包含问题的数据库文件，即我想从中更改问题，那么如何执行此任务？等待您的宝贵回复。

Hello sir

Actually i need your help for developing android application which interacts with database in it.So will you please provide simplest code to store and retrieve data from database.And also tell me that what prerequisites it requires like Odbc or anything.
Lastly i would like to know that if we are developing any static application by providing database(like application for online exam and in it we are going to provide some questions) as i mentioned that it is offline,so if i want to change that database file which contains questions i.e i want to change questions from it then how to perform this task?waiting for yours valuable response.

推荐答案

参考



android-sqlite-database-tutorial [ ^ ]



android-sqlite-tutorial [ ^ ]

商务舱：

Business Class :

package com.example.employeeinfowcfsqlite;

import java.util.ArrayList;
import java.util.HashMap;

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

public class EmployeeSqliteDbInfo
{
	public static String KEY_ID = "id";
	public static String KEY_NAME = "name";
	public static String KEY_EMAIL = "email";
	public static String KEY_JOB = "job";
	public static String KEY_CITY = "city";
	public static String KEY_COMPANY = "company";
	public static String KEY_PHONE = "phone";
	public static String KEY_NOTES = "notes";
	
	private static final String DB_NAME = "EmployeeList";
	private static final String DB_TABLE = "Employee";
	private static final int DB_VERSION = 1;
	
	private final Context ctx;
	private EmpInfo empInfo;
	private SQLiteDatabase sqliteDb;
	
	public EmployeeSqliteDbInfo(Context ctx)			// CTOR
	{
		this.ctx = ctx;
	}
	
	public EmployeeSqliteDbInfo OpenConnection()		// OPEN CONNECTION
	{
		empInfo = new EmpInfo(ctx);
		sqliteDb = empInfo.getWritableDatabase();
		return this;
	}
	
	public void CloseConnection()						// CLOSE CONNECTION
	{	
		sqliteDb.close();
	}
	
	public long AddData(int empId, String Name, String Email, String Job, String City, String Company, String Phone, String Notes)
	{
		ContentValues values = new ContentValues();
		values.put(KEY_ID, empId);
		values.put(KEY_NAME, Name);
		values.put(KEY_EMAIL, Email);
		values.put(KEY_JOB, Job);
		values.put(KEY_CITY, City);
		values.put(KEY_COMPANY, Company);
		values.put(KEY_PHONE, Phone);
		values.put(KEY_NOTES, Notes);
		
		return sqliteDb.insert(DB_TABLE, null, values);
	}
	
	public void UpdateData(int empId, String Name, String Email, String Job, String City, String Company, String Phone, String Notes)
	{
		ContentValues values = new ContentValues();
		values.put(KEY_ID, empId);
		values.put(KEY_NAME, Name);
		values.put(KEY_EMAIL, Email);
		values.put(KEY_JOB, Job);
		values.put(KEY_CITY, City);
		values.put(KEY_COMPANY, Company);
		values.put(KEY_PHONE, Phone);
		values.put(KEY_NOTES, Notes);
		
		sqliteDb.update(DB_TABLE, values, KEY_ID + "=" + empId, null);
	}
	
	public void DeleteData(int empId)
	{
		sqliteDb.delete(DB_TABLE, KEY_ID + "=" + empId, null);
	}
	
	
	public ArrayList<HashMap<String, String>> GetData(int empId)
	{	
		String[] Columns = new String[] { KEY_ID, KEY_NAME, KEY_EMAIL, KEY_JOB, KEY_CITY, KEY_COMPANY, KEY_PHONE, KEY_NOTES };
				
		ArrayList<HashMap<String, String>> empInfo = new ArrayList<HashMap<String,String>>();
		
		if(empId != 0)
		{
			empInfo.clear();
			Cursor crs = sqliteDb.query(DB_TABLE, Columns, KEY_ID + "=" + empId, null, null, null, null);
		
			for(crs.moveToFirst(); !crs.isAfterLast(); crs.moveToNext())
			{
				HashMap<String, String> item = new HashMap<String, String>();
				item.put("ID", crs.getString(crs.getColumnIndex(KEY_ID)));
				item.put("NAME", crs.getString(crs.getColumnIndex(KEY_NAME)));
				item.put("EMAIL", crs.getString(crs.getColumnIndex(KEY_EMAIL)));
				item.put("JOB", crs.getString(crs.getColumnIndex(KEY_JOB)));
				item.put("CITY", crs.getString(crs.getColumnIndex(KEY_CITY)));
				item.put("COMPANY", crs.getString(crs.getColumnIndex(KEY_COMPANY)));
				item.put("PHONE", crs.getString(crs.getColumnIndex(KEY_PHONE)));
				item.put("NOTES", crs.getString(crs.getColumnIndex(KEY_NOTES)));
						
				empInfo.add(item);
			}
		}
		else
		{
			empInfo.clear();
			Cursor crs = sqliteDb.query(DB_TABLE, Columns, null, null, null, null, null);
			
			for(crs.moveToFirst(); !crs.isAfterLast(); crs.moveToNext())
			{
				HashMap<String, String> item = new HashMap<String, String>();
				item.put("ID", crs.getString(crs.getColumnIndex(KEY_ID)));
				item.put("NAME", crs.getString(crs.getColumnIndex(KEY_NAME)));
				item.put("EMAIL", crs.getString(crs.getColumnIndex(KEY_EMAIL)));
				item.put("JOB", crs.getString(crs.getColumnIndex(KEY_JOB)));
				item.put("CITY", crs.getString(crs.getColumnIndex(KEY_CITY)));
				item.put("COMPANY", crs.getString(crs.getColumnIndex(KEY_COMPANY)));
				item.put("PHONE", crs.getString(crs.getColumnIndex(KEY_PHONE)));
				item.put("NOTES", crs.getString(crs.getColumnIndex(KEY_NOTES)));
						
				empInfo.add(item);
			}
		}
		
		return empInfo;
	}
	
	
	// SQLITE DATABASE
	private static class EmpInfo extends SQLiteOpenHelper
	{

		public EmpInfo(Context ctx) 
		{
			super(ctx, DB_NAME, null, DB_VERSION);
		}

		@Override
		public void onCreate(SQLiteDatabase db) 
		{
			String query = "CREATE TABLE " + DB_TABLE + " (" +
							KEY_ID + " INTEGER PRIMARY KEY," + 
							KEY_NAME + " TEXT," + KEY_EMAIL + " TEXT," +
							KEY_JOB + " TEXT," + KEY_CITY + " TEXT," +
							KEY_COMPANY + " TEXT," + KEY_PHONE + " TEXT," +
							KEY_NOTES + " TEXT);";
			db.execSQL(query);
		}

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

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