Android开发—使用已有的sql数据库

先用SQLite管理工具，sqliteadmin 具体操作很简单，在这里我就不详细介绍的了，但有一个地方时候很值得注意的，就是用sqliteadmin创建数据库的时候，数据库保存的路径不能是中文路径，中文路径会出现下面的错误提示：





我在sqliteadmin 创建好数据库StuDB，里面的表如下：





将创建好的数据库在DDMS中点击

导入到data/data/程序的包名/





SQLiteTestActivity.java

package com.lingdududu.test;

import android.app.Activity;
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.Toast;

public class SQLiteTestActivity extends Activity {
/** Called when the activity is first created. */
private EditText studentText;
private EditText teacherText;
private Button queryBtn;
SQLiteDatabase stuDb;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

studentText = (EditText)findViewById(R.id.stu_name);
teacherText = (EditText)findViewById(R.id.teacher_name);
queryBtn = (Button)findViewById(R.id.query);

queryBtn.setOnClickListener(new queryListener());
}
class queryListener implements OnClickListener{

@Override
public void onClick(View v) {
//调用查询方法
query();
stuDb.close();
}
}
//查询方法
private void  query() {
//打开或者创建数据库
stuDb = SQLiteDatabase.openOrCreateDatabase("data/data/com.lingdududu.test/StuDB.s3db", null);
try {
String string =studentText.getText().toString();
String sql = "Select sname from Student where snumber="+string;
Cursor cursor = stuDb.rawQuery(sql,null);
cursor.moveToFirst();
teacherText.setText(cursor.getString(cursor.getColumnIndex("sname")));
} catch (Exception e) {
Toast.makeText(this, "请检查输入的学生学号是否正确", Toast.LENGTH_LONG).show();
}
}
}

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/input_name"
/>
<EditText
android:id="@+id/stu_name"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
<Button
android:id="@+id/query"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="开始查询"
/>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/teacher_name"
/>
<EditText
android:id="@+id/teacher_name"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:editable="false"
/>
</LinearLayout>

strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="hello">Hello World, SQLiteTestActivity!</string>
<string name="app_name">SQLiteTest</string>
<string name="input_name">请输入学生学号</string>
<string name="teacher_name">该学生的姓名</string>
</resources>

效果图：