在cmd窗口中查询android的sqlite3数据库表之步骤
本文主要是写了一个android程序对sqlite3中数据库的employee表的插入、删除的操作,然后在cmd窗口中用sql命令查询employee表的操作过程.
1、第一步:首先把程序写好.
1.1、创建一个MainActivity类,代码如下:
package com.example.datastorege.action;
import com.example.datastorege.R;
import com.example.datastorege.R.layout;
import com.example.datastorege.R.menu;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
1.2、创建一个SQLiteOpenHelperImpl类,这个类是继承SQLiteOpenHelper类的,SQLiteOpenHelperImpl主要作用把创建的DB、DB的版本号通过SQLiteOpenHelper来实现,同时好在EmployeeDao获取db对象，以便操作sqlite3中的employee表.中代码如下:
package com.example.datastorege.dao;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
public class SQLiteOpenHelperImpl extends SQLiteOpenHelper{
private static final String TAG="EmployeeDaoJunit";
private static final int DB_VERSION=1;
private static final String DB_NAME="testDb.db";
private static final String SQL_TABLE_NAME="create table employee(id INTEGER PRIMARY KEY,empName varchar(30),sex int);";
public SQLiteOpenHelperImpl(Context context) {
super(context, DB_NAME, null, DB_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(SQL_TABLE_NAME);
Log.i(TAG, "execSQL successful");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
}
1.3、创建操作sqlite3的dao类---EmployeeDao,这个类主要是操作sqlite3中testDb.db数据库名,代码如下:
package com.example.datastorege.dao;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import com.example.datastorege.model.Employee;
public class EmployeeDao {
private SQLiteOpenHelperImpl helper;
private SQLiteDatabase db;
public EmployeeDao(Context context){
helper=new SQLiteOpenHelperImpl(context);
}
public void insert(Employee emp){
db=helper.getWritableDatabase();
db.execSQL("insert into employee values(?,?,?)", new Object[]{emp.getId(),emp.getEmpName(),emp.getSex()});
}
public void update(Employee emp){
db=helper.getWritableDatabase();
db.execSQL("update employee set empName=?,sex=? where id=?",new Object[]{emp.getEmpName(),emp.getSex(),emp.getId()});
}
public void delete(int id){
db=helper.getWritableDatabase();
db.execSQL("delete from employee where id=?", new Object[]{id});
}
public Employee queryBeanById(int id){
Employee emp=null;
db=helper.getWritableDatabase();
Cursor cursor=db.rawQuery("",new String[]{});
if(cursor.moveToNext()){
emp=new Employee();
emp.setEmpName(cursor.getString(cursor.getColumnIndex("empName")));
emp.setSex(cursor.getInt(cursor.getColumnIndex("sex")));
return emp;
}
return null;
}
}
1.4、创建一个实体bean.
package com.example.datastorege.model;
public class Employee {
private int id;
private String empName;
private int sex;
public Employee(){};
public Employee(int id,String empName,int sex){
this.id=id;
this.empName=empName;
this.sex=sex;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getEmpName() {
return empName;
}
public void setEmpName(String empName) {
this.empName = empName;
}
public int getSex() {
return sex;
}
public void setSex(int sex) {
this.sex = sex;
}
@Override
public String toString() {
return this.id+"--"+this.empName+"--"+this.sex;
}
}
1.5、创建一个android的junit测试类:
package com.example.datastorege;
import com.example.datastorege.dao.EmployeeDao;
import com.example.datastorege.model.Employee;
import android.test.AndroidTestCase;
import android.util.Log;
public class EmployeeDaoJunit extends AndroidTestCase{
private static final String TAG="EmployeeDaoJunit";
public void add(){
EmployeeDao employeeDao=new EmployeeDao(this.getContext());
employeeDao.insert(new Employee(2,"tangfq",1));
Log.i(TAG, "EmployeeDao--->insert");
}
public void delete(){
EmployeeDao employeeDao=new EmployeeDao(this.getContext());
employeeDao.delete(1);
Log.i(TAG, "EmployeeDao--->delete");
}
}
以上就是要写的程序.查询和修改在测试类添加就行了.操作和新增、删除类似.
2、第二步:运行上面写的程序及操作sqlite3数据库.
2.1、运行EmployeeDaoJunit ,在运行它之前,要先运行sqlite3.exe,运行起后才执行EmployeeDaoJunit ,当junit运行绿色时,则证明写正确了.此时,在运行中输入"cmd"--->adb shell---->ls---->cd data---->cd data--->(在eclipse中打开DDMS Pespective,点击"File Explorer"查看,data--->data--->你的项目名包路径,如我的是com.example.datastorege)--->databases--->你的数据库名,我的数据库名为testDb.db--->sqlite3 testDb.db--->select id,empName,sex from employee;---->显示操作的employee表的结果.
操作的步骤是上面所描述的,如果有什么疑问或错误之处,敬请留言!谢谢了!