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!