MainActivity.java
package com.example.sqlite;
import java.util.ArrayList;
import java.util.List;
import android.app.Activity;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity implements OnClickListener{
private static final String TAG="Add";
private static final ListAdapter listAdapter = null;
private EditText ecode,ename,ebirth;
private Button badd,bdel,bupdate,bsele;
private SQLiteDatabase db=null;
private TextView tedatashow;
private ListView datashow;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ecode=(EditText)findViewById(R.id.ecode);
ename=(EditText)findViewById(R.id.ename);
ebirth=(EditText)findViewById(R.id.ebirth);
badd=(Button)findViewById(R.id.badd);
bdel=(Button)findViewById(R.id.bdel);
bupdate=(Button)findViewById(R.id.bupdate);
bsele=(Button)findViewById(R.id.bsele);
tedatashow=(TextView)findViewById(R.id.tedatashow);
datashow=(ListView)findViewById(R.id.datashow);
badd.setOnClickListener((android.view.View.OnClickListener) this);
bdel.setOnClickListener((android.view.View.OnClickListener) this);
bsele.setOnClickListener((android.view.View.OnClickListener) this);
bupdate.setOnClickListener((android.view.View.OnClickListener) this);
}
public void onClick(View v)
{
// TODO Auto-generated method stub
MyDBHelper helper=new MyDBHelper(this);
String code=ecode.getText().toString().trim();
String name=ename.getText().toString().trim();
String birth=ebirth.getText().toString().trim();
if(v==badd)
{
if(code.length()!=0 && name.length()!=0 && birth.length()!=0)
{
try
{
db=helper.getWritableDatabase();
String sql="INSERT INTO user(ecode,ename,ebirth)" +"VALUES('"+ecode.getText()+"','" +ename.getText()+"','" +ebirth.getText()+"')";
db.execSQL(sql);
Toast.makeText(this, "添加成功！", Toast.LENGTH_LONG).show();
ecode.setText("");
ename.setText("");
ebirth.setText("");
}
catch(Exception e)
{
Toast.makeText(this, "出错了！"+ e.getMessage(),Toast.LENGTH_LONG).show();
}
}
else
Toast.makeText(this, "学号和姓名出生日期不能为空！", Toast.LENGTH_LONG).show();
}
if(v==bdel)
{
if(code.length()!=0)
{
try
{
db=helper.getWritableDatabase();
String sql="delete from user where ecode='"+ecode.getText()+"'";
db.execSQL(sql);
Toast.makeText(this, "成功删除！", Toast.LENGTH_LONG).show();
ecode.setText("");
}
catch(Exception e)
{
Toast.makeText(this, "出错了！", Toast.LENGTH_LONG).show();
}
}
}
if(v==bupdate)
{
db=helper.getWritableDatabase();
if(code.length()!=0 && name.length()!=0 && birth.length()!=0)
{
try
{
String sql="update user set ecode='"+ecode.getText() +"'where ename='"+ename.getText()+"'and ebirth='" +ebirth.getText()+"'and ecode='" +ecode.getText()+"'";
db.execSQL(sql);
Toast.makeText(this, "成功更新！", Toast.LENGTH_LONG).show();
ecode.setText("");
ename.setText("");
ebirth.setText("");
}
catch(Exception e)
{
Toast.makeText(this, "出错了！"+e.getMessage(),Toast.LENGTH_LONG).show();
}
}
else
Toast.makeText(this, "学号姓名出生日期不能为空！", Toast.LENGTH_LONG).show();
}
if(v==bsele)
{
if(code.length()!=0)
{
try
{
ArrayList<String> all=new ArrayList<String>();
String sql="select * from user where ecode =? or ename =? or ebirth =? ";
Cursor result=helper.getReadableDatabase().rawQuery(sql,new String[]{code,code,code});
while(result.moveToNext())
{
all.add("["+result.getString(0)+"]"+""+result.getString(1)+","+result.getString(2));
}
ArrayAdapter<String> arrayAdapter=new ArrayAdapter<String>(this, android.R.layout.simple_expandable_list_item_1,all);
datashow.setAdapter(arrayAdapter);
}
catch(Exception f)
{
Toast.makeText(this, "显示不了", Toast.LENGTH_LONG).show();
}
}
}
db.close();
}
@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;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
MyDBHelper.java
package com.example.sqlite;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
public class MyDBHelper extends SQLiteOpenHelper{
public MyDBHelper(Context context)
{
super(context,"mvdb.db",null,2);
}
public void onCreate(SQLiteDatabase db)
{
String sql="create table user(ecode text,ename text,ebirth text);";
db.execSQL(sql);
}
public void onUpgrade(SQLiteDatabase db,int arg1,int arg2)
{
String sql="create table user(ecode text,ename text,ebirth text);";
db.execSQL(sql);
this.onCreate(db);
}
}
显示更新成功了，但我在查询数据时按选择按钮并没有更新
