安卓数据库开发helper

package com.mytest.myapplication;

public class MyInfo {
public MyInfo(int id,String name,String value)
{
_ID=id;
_Name=name;
_Value=value;
}

public int _ID;
public String _Name;
public  String _Value;

}

package com.mytest.myapplication;

import android.database.sqlite.SQLiteOpenHelper;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.util.Log;

public class MySQLiteOpenHelper extends SQLiteOpenHelper{
public static final String TAG = “database”;
private static final String DATABASE_NAME = “test.db”;//数据库名字
private static final int DATABASE_VERSION = 1;//数据库版本号
public static final String TABLE_NAME = “myTable”; //表名

private static final String CREATE_TABLE = "create table " + TABLE_NAME + " ("
        + "ID integer primary key autoincrement,"
        + "Name text, "
        + "Value text);";//创建数据库里的表的sql语句
public MySQLiteOpenHelper(Context context)//创建数据库
{
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
public MySQLiteOpenHelper(Context context, String name, SQLiteDatabase.CursorFactory factory, int version)//创建数据库
{
    super(context, name, factory, version);
}
@Override
public void onCreate(SQLiteDatabase db)
{
    Log.i(TAG, "onCreate: ");
    db.execSQL(CREATE_TABLE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
{

    String sql = "DROP TABLE IF EXISTS " + DATABASE_NAME;
    db.execSQL(sql);
    onCreate(db);
}

}

package com.mytest.myapplication;

import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;

import android.content.ContentValues;
import java.util.ArrayList;
import java.util.Dictionary;
import java.util.List;
import java.util.Map;

public class DataBaseDAO {
private MySQLiteOpenHelper myDbHelper;
public DataBaseDAO(Context context)
{
myDbHelper=new MySQLiteOpenHelper(context);

}
public void Add(MyInfo info)//增加插入数据
{
SQLiteDatabase db = myDbHelper.getWritableDatabase();
// db.execSQL(“insert into “+myDbHelper.TABLE_NAME+”(ID,Name,Value) values(?,?,?)”,info._ID, info._Name,info._Value);
ContentValues values = new ContentValues();
values.put(“ID”,info._ID);
values.put(“Name”,info._Name);
values.put(“Value”,info._Value);
db.insert(myDbHelper.TABLE_NAME, null, values);
db.close();

}
public void Delete(String Name)//删除数据
{
    SQLiteDatabase db = myDbHelper.getWritableDatabase();

    db.execSQL("delete from "+myDbHelper.TABLE_NAME+" where Name=?",new String[]{Name});

}

public void Update(String name, Map<String,Object> map)//更新数据
{
SQLiteDatabase db = myDbHelper.getWritableDatabase();
ContentValues values = new ContentValues();
for(Map.Entry<String, Object> entry : map.entrySet())
{
if(entry.getKey()==“ID”)
{
values.put(entry.getKey(),(Integer) entry.getValue());
}
else
{
values.put(entry.getKey(),(String) entry.getValue());
}
}
db.update(myDbHelper.TABLE_NAME,values,“Name=?”, new String[]{name});

db.close();
}

public List<MyInfo> findAll()//查找所有数据
{
    SQLiteDatabase db = myDbHelper.getWritableDatabase();
    List<MyInfo> list = new ArrayList<MyInfo>();
    Cursor cursor = db.rawQuery("select * from "+myDbHelper.TABLE_NAME,null);
    while(cursor.moveToNext())
    {
        int id = cursor.getInt(cursor.getColumnIndex("ID"));
        String name = cursor.getString(cursor.getColumnIndex("Name"));
        String value = cursor.getString(cursor.getColumnIndex("Value"));

        MyInfo userInfo = new MyInfo(id,name,value);
        list.add(userInfo);
    }
    cursor.close();
    db.close();
    return list;
}

}

package com.mytest.myapplication;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

import java.util.HashMap;
import java.util.Map;

import java.util.List;

public class DataBaseActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_data_base);
    dbd=new DataBaseDAO(this);
    Regedit();
}
DataBaseDAO dbd;
public List<MyInfo> List;
public void Regedit()
{
    Button addButton=(Button)findViewById(R.id.button_Add);
   addButton.setOnClickListener(new View.OnClickListener() {
       @Override
       public void onClick(View v) {
           TextView tvName=(EditText)findViewById(R.id.editText_Name);
           TextView tvID=(EditText)findViewById(R.id.editText_ID);
           TextView tvValue=(EditText)findViewById(R.id.editText_Value);
           MyInfo mi=new MyInfo(Integer.parseInt((tvID.getText().toString())),tvName.getText().toString(),tvValue.getText().toString());
           dbd.Add(mi);
       }
   });

    Button deleteButton=(Button)findViewById(R.id.button_Delete);
    deleteButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            TextView tvName=(EditText)findViewById(R.id.editText_DeleteName);
            dbd.Delete(tvName.getText().toString());
        }
    });
    Button updateButton=(Button)findViewById(R.id.button_Upatate);
    updateButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            TextView tvName=(EditText)findViewById(R.id.editText_UpdateID);
            TextView tvID=(EditText)findViewById(R.id.editText_UpDateName);
            TextView tvValue=(EditText)findViewById(R.id.editText_UpdateValue);
          Map<String,Object> map=new HashMap<String,Object>();
          map.put("ID",Integer.valueOf(tvID.getText().toString()));
          map.put("Value",tvValue.getText().toString());
            dbd.Update(tvName.getText().toString(),map);
        }
    });



    Button findButton=(Button)findViewById(R.id.button_Find);
    findButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            TextView tvFind=(EditText)findViewById(R.id.editText_Find);
            tvFind.setText("");
            List=dbd.findAll();
            for (int i = 0; i < List.size(); i++) {
                MyInfo mi=List.get(i);
                tvFind.append(String.valueOf(mi._ID)+",");
                tvFind.append(mi._Name+",");
                tvFind.append(mi._Value+",");
            }
        }
    });

}

}

<Button
    android:id="@+id/button_Add"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentStart="true"
    android:layout_alignParentTop="true"
    android:layout_marginStart="30dp"
    android:layout_marginTop="39dp"
    android:text="增" />

<Button
    android:id="@+id/button_Delete"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentTop="true"
    android:layout_alignStart="@+id/button_Add"
    android:layout_marginTop="129dp"
    android:text="删" />

<Button
    android:id="@+id/button_Upatate"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentTop="true"
    android:layout_alignStart="@+id/button_Add"
    android:layout_marginTop="216dp"
    android:text="改" />

<Button
    android:id="@+id/button_Find"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:layout_alignStart="@+id/button_Add"
    android:layout_marginBottom="208dp"
    android:text="查" />

<EditText
    android:id="@+id/editText_ID"
    android:layout_width="63dp"
    android:layout_height="wrap_content"
    android:layout_alignParentEnd="true"
    android:layout_alignTop="@+id/button_Add"
    android:layout_marginEnd="190dp"
    android:ems="10"
    android:inputType="textMultiLine" />

<EditText
    android:id="@+id/editText_Name"
    android:layout_width="63dp"
    android:layout_height="wrap_content"
    android:layout_alignParentEnd="true"
    android:layout_alignTop="@+id/button_Add"
    android:layout_marginEnd="107dp"
    android:ems="10"
    android:inputType="textMultiLine" />

<EditText
    android:id="@+id/editText_Value"
    android:layout_width="66dp"
    android:layout_height="wrap_content"
    android:layout_alignParentEnd="true"
    android:layout_alignTop="@+id/button_Add"
    android:layout_marginEnd="13dp"
    android:ems="10"
    android:inputType="textMultiLine" />

<EditText
    android:id="@+id/editText_DeleteName"
    android:layout_width="63dp"
    android:layout_height="wrap_content"
    android:layout_alignStart="@+id/editText_ID"
    android:layout_alignTop="@+id/button_Delete"
    android:ems="10"
    android:inputType="textMultiLine" />

<EditText
    android:id="@+id/editText_Find"
    android:layout_width="322dp"
    android:layout_height="156dp"
    android:layout_alignParentBottom="true"
    android:layout_alignStart="@+id/button_Add"
    android:layout_marginBottom="23dp"
    android:ems="10"
    android:inputType="textMultiLine" />

<EditText
    android:id="@+id/editText_UpDateName"
    android:layout_width="63dp"
    android:layout_height="wrap_content"
    android:layout_alignStart="@+id/editText_ID"
    android:layout_alignTop="@+id/button_Upatate"
    android:ems="10"
    android:inputType="textMultiLine" />

<EditText
    android:id="@+id/editText_UpdateID"
    android:layout_width="66dp"
    android:layout_height="wrap_content"
    android:layout_alignEnd="@+id/editText_Name"
    android:layout_alignTop="@+id/button_Upatate"
    android:ems="10"
    android:inputType="textMultiLine" />

<EditText
    android:id="@+id/editText_UpdateValue"
    android:layout_width="75dp"
    android:layout_height="wrap_content"
    android:layout_alignEnd="@+id/editText_Value"
    android:layout_alignTop="@+id/button_Upatate"
    android:ems="10"
    android:inputType="textMultiLine" />