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Android编程之数据库Sql编程实例分析

时间:2021-02-19 15:17:11 | 栏目:Android代码 | 点击:

本文实例讲述了Android编程之数据库Sql编程实现方法。分享给大家供大家参考。具体分析如下:

Android中安装轻量级数据库Sqlite,现在测试数据库基本操作。

数据库基本操作:创建表,插入,删除可以用execSQL();读取可以用rawQuery();这两个函数都可以标准SQL语句进行操作。

源代码:

package com.test.sql; 
import android.app.Activity; 
import android.content.Context; 
import android.database.Cursor; 
import android.database.sqlite.SQLiteDatabase; 
import android.database.sqlite.SQLiteOpenHelper; 
import android.os.Bundle; 
import android.util.Log; 
public class test_sql extends Activity 
{ 
 DatabaseHelper mOpenHelper; 
 private static final String DATABASE_NAME = "test.db"; 
 private static final int DATABASE_VERSION = 1; 
 private static class DatabaseHelper extends SQLiteOpenHelper { 
  DatabaseHelper(Context context) { 
   super(context, DATABASE_NAME, null, DATABASE_VERSION); 
  } 
  @Override 
  public void onCreate(SQLiteDatabase db) 
  { 
   //新建一个用户表 
   //共有5项:Id Pwd Name OnLineTime Level 
   db.execSQL("CREATE TABLE User_Table ('Id' INT,'Pwd' VARCHAR,'Name' VARCHAR,'OnLineTime' INT,'Level' INT)");
  } 
  @Override 
  public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
  } 
 } 
 /** Called when the activity is first created. */ 
 @Override 
 public void onCreate(Bundle savedInstanceState) { 
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);
  mOpenHelper = new DatabaseHelper(this);
  SQLiteDatabase db = mOpenHelper.getWritableDatabase();
  //清空数据 
  db.execSQL("DELETE FROM User_Table"); 
  //插入数据10000 123456 "jdh" 0 0 
  //插入数据10001 123456 "jim" 0 0 
  db.execSQL("INSERT INTO User_Table VALUES (?,?,?,?,?)", new Object[]{10000,"123456","jdh",0,0}); 
  db.execSQL("INSERT INTO User_Table VALUES (?,?,?,?,?)", new Object[]{10001,"123456","jim",0,0}); 
  //读取数据 
  Cursor cursor = db.rawQuery("SELECT * FROM User_Table WHERE Name = ?",new String[]{"jdh"}); 
  while (cursor.moveToNext()) 
  { 
   String str = cursor.getInt(0) + cursor.getString(1) + cursor.getString(2) + cursor.getInt(3) + cursor.getInt(4); 
   Log.i("str:", str); 
  }  
 } 
}

希望本文所述对大家的Android程序设计有所帮助。

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