数据库的基本操作

1.这是数据库操作的一个帮助类，用来创建数据库
package com.kotei.operation;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
public class DataBaseOpenHelp extends SQLiteOpenHelper {
 private static final String name = "guotu";
 private static final int version = 1;
 public DataBaseOpenHelp(Context context) {
  super(context, name, null, version);
 }
 /**
  * taskSchedule:任务列表
  * 1.task_id:任务ID
  * 2.task_name:任务的名字
  * 3.task_type:任务的类型
  * 4.sendman_name:发送人的姓名
  * 5.task_get_time:任务获取时间
  * 6.task_state:任务的状态
  * 7.task_content:任务的内容
  * 8.spareattribute1:备用属性
  * 9.spareattribute2:备用属性
  * 
  */
 @Override
 public void onCreate(SQLiteDatabase db) {
  db.execSQL("create table taskSchedule (task_id integer primary key autoincrement,task_name varchar(20),task_type varchar(20),sendman_name varchar(20),task_get_time varchar(30),task_state varchar(10),task_content varchar(500),spareattribute1 varchar(20),spareattribute2 varchar(20))");
 }
 @Override
 public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
  db.execSQL("drop table if exists taskSchedule");
  onCreate(db);
 }
}

2.数据库增删查改的操作
package com.kotei.show;
import com.kotei.operation.DataBaseOpenHelp;
import android.app.Activity;
import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class SQLitTestActivity extends Activity {
 private DataBaseOpenHelp dboh;
 private SQLiteDatabase sd;
 private TextView dbinfo;
 private Button bt_check;
 private Button bt_insert;
 private Button bt_update;
 private Button bt_delet;
 private Button bt_conditionscheck;
 private EditText et_check;
 private EditText et_insert;
 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);
  bt_insert = (Button) findViewById(R.id.bt_insert);
  bt_check = (Button) findViewById(R.id.bt_check);
  bt_update = (Button) findViewById(R.id.bt_update);
  bt_delet = (Button) findViewById(R.id.bt_delet);
  bt_conditionscheck = (Button) findViewById(R.id.bt_conditionscheck);
  dbinfo = (TextView) findViewById(R.id.dbinfo);
  bt_insert.setOnClickListener(listener);
  bt_check.setOnClickListener(listener);
  bt_update.setOnClickListener(listener);
  bt_delet.setOnClickListener(listener);
  bt_conditionscheck.setOnClickListener(listener);
  dboh = new DataBaseOpenHelp(SQLitTestActivity.this);
 }
 OnClickListener listener = new OnClickListener() {
  @Override
  public void onClick(View v) {
   switch (v.getId()) {
   case R.id.bt_check:
    String text = check(2);
    dbinfo.setText(text);
    break;
   case R.id.bt_insert:
    insert();
    break;
   case R.id.bt_update:
    update();
    break;
   case R.id.bt_delet:
    delet();
    break;
   case R.id.bt_conditionscheck:
    conditionsCheck();
    break;
   default:
    break;
   }
  }
 };
 /**
  * 保存数据到数据表
  * 
  * @creattime 2012-3-13
  * 
  */
 private void insert() {
  sd = dboh.getWritableDatabase();
  sd.execSQL(
    "insert into taskSchedule(task_name,task_type,sendman_name,task_get_time,task_state,task_content,spareattribute1,spareattribute2) values(?,?,?,?,?,?,?,?)",
    new Object[] { "戴国伟的短信调度", "短信调度", "小猪", "2012-3-13 14:30:29",
      "新下达", "去派出所收保护费", null, null });
  sd.close();
 }
 /**
  * 查询数据
  * 
  * @creattime 2012-3-13
  * 
  * @param 要查询的数据的id
  * @return
  */
 public String check(int id) {
  sd = dboh.getReadableDatabase();
  // 以task_id查询所有数据
  Cursor cursor = sd.rawQuery("select * from taskSchedule where task_id = ?", new String[] { String.valueOf(id) });
  while (cursor.moveToNext()) {
   // 第一种方法查询所有数据
   String s = cursor.getInt(0) + "," + cursor.getString(1) + ","
     + cursor.getString(2) + "," + cursor.getString(3) + ","
     + cursor.getString(4) + "," + cursor.getString(5) + ","
     + cursor.getString(6) + "," + cursor.getString(7) + ","
     + cursor.getString(8);
   // 第二种方法查询所有数据
   String s2 = cursor.getString(cursor.getColumnIndex("task_id"))
     + cursor.getString(cursor.getColumnIndex("task_name"))
     + cursor.getString(cursor.getColumnIndex("task_type"))
     + cursor.getString(cursor.getColumnIndex("sendman_name"))
     + cursor.getString(cursor.getColumnIndex("task_get_time"))
     + cursor.getString(cursor.getColumnIndex("task_state"))
     + cursor.getString(cursor.getColumnIndex("task_content"))
     + cursor.getString(cursor.getColumnIndex("spareattribute1"))
     + cursor.getString(cursor.getColumnIndex("spareattribute2"));
   return s;
  }
  cursor.close();
  sd.close();
  return null;
 }
 /**
  * 更新数据
  * 
  * @creattime 2012-3-13
  * 
  */
 public void update() {
  sd = dboh.getWritableDatabase();
  ContentValues cv = new ContentValues();
  // 将"task_name"字段的值修改成为"奥巴马的任务"
  cv.put("task_name", "奥巴马的任务");
  sd.update("taskSchedule", cv, "task_id=?", new String[] { String.valueOf(2)});
  cv.clear();
  sd.close();
 }
 
 /**
  * 删除数据
  * 
  * @creattime 2012-3-13
  *
  */
 public void delet(){
  sd = dboh.getWritableDatabase();
  // 删除task_id=1的记录
  sd.delete("taskSchedule", "task_id=?", new String[]{String.valueOf(1)});
  sd.close();
 }
 
 /**
  * 条件查询
  * 
  * @creattime 2012-3-13
  *
  */
 public void conditionsCheck(){
  sd = dboh.getReadableDatabase();
  // 查询task_id 为 2 的task_name的值
  Cursor cursor = sd.query("taskSchedule", new String[]{"task_id","task_name"}, "task_id=?", new String[]{String.valueOf(2)}, null, null, null);
  while(cursor.moveToNext()){
   String task_name = cursor.getString(cursor.getColumnIndex("task_name"));
   dbinfo.setText(task_name);
  }
 }
}

3.不要忘记添加权限
<uses-permission android:name="android.permission.ACCESS_CHECKIN_PROPERTIES"/>

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