主要就是创建数据库，添加、查询、更新、删除这几项。
首先是创建数据库，这里要用到SQLiteOpenHelper这个类，这是个抽象类，我们需要去继承他，它里面有两个抽象方法需要实现：onCreate()和onUpgrade(),分别是创建和升级数据库用的。
package com.wr.sqlite;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;
import android.widget.Toast;
public class MyDatebaseHelper extends SQLiteOpenHelper {
public static final String CREATE_BOOK = "create table Book ("
+ "id integer primary key autoincrement, " + "author text, "
+ "price real, " + "pages integer, " + "name text) ";
public static final String CREATE_CATEGORY = "create table Category ("
+ "id integer primary key autoincrement, " + "category_name text, "
+ "category_code integer) ";
private Context mContext;
public MyDatebaseHelper(Context context, String name,
CursorFactory factory, int version) {
super(context, name, factory, version);
mContext = context;
// TODO Auto-generated constructor stub
}
@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
db.execSQL(CREATE_BOOK);
db.execSQL(CREATE_CATEGORY);
Toast.makeText(mContext, "Create succeeded", Toast.LENGTH_SHORT).show();
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
switch (oldVersion) {
case 1:
db.execSQL(CREATE_CATEGORY);
case 2:
db.execSQL("alter table Book add column category_id integer");
}
}
}
这里将见表语句定义成了字符串，在哦你Create（）方法中建表。
然后就是对数据库的一系列的操作，首先布局文件activity_main.xml。
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<Button
android:id="@+id/create_database"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Create database" />
<Button
android:id="@+id/add_data"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Add date" />
<Button
android:id="@+id/update_data"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Update date" />
<Button
android:id="@+id/delete_data"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Delete date" />
<Button
android:id="@+id/query_data"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Query date" />
<Button
android:id="@+id/replace_data"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Replace date" />
</LinearLayout>
最后在MainActiity中，实现一系列的操作。MainActivity.java
package com.wr.sqlite;
import android.app.Activity;
import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class MainActivity extends Activity {
private MyDatebaseHelper dbHelper;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
dbHelper = new MyDatebaseHelper(this, "BookStore.db", null, 2);
Button createDatabase = (Button) findViewById(R.id.create_database);
createDatabase.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
dbHelper.getWritableDatabase();
}
});
Button addData = (Button) findViewById(R.id.add_data);
addData.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
SQLiteDatabase db = dbHelper.getWritableDatabase();
ContentValues values = new ContentValues();
values.put("name", "The Da Vinci Code");
values.put("author", "Dan Brown");
values.put("pages", 454);
values.put("price", 16.96);
db.insert("Book", null, values);
values.clear();
values.put("name", "The Lost Sysbol");
values.put("author", "Dan Brown");
values.put("pages", 510);
values.put("price", 19.95);
db.insert("Book", null, values);
}
});
Button updateData = (Button) findViewById(R.id.update_data);
updateData.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
SQLiteDatabase db = dbHelper.getWritableDatabase();
ContentValues values = new ContentValues();
values.put("price", 10.99);
db.update("Book", values, "name = ?",
new String[] { "The Da Vinci Code" });
}
});
Button deleteData = (Button) findViewById(R.id.delete_data);
deleteData.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
SQLiteDatabase db = dbHelper.getWritableDatabase();
db.delete("Book", "pages > ?", new String[] { "500" });
}
});
Button queryData = (Button) findViewById(R.id.query_data);
queryData.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
SQLiteDatabase db = dbHelper.getWritableDatabase();
Cursor cursor = db.query("Book", null, null, null, null, null,
null);
if (cursor.moveToFirst()) {
do {
String name = cursor.getString(cursor
.getColumnIndex("name"));
String author = cursor.getString(cursor
.getColumnIndex("author"));
int pages = cursor.getInt(cursor
.getColumnIndex("pages"));
double price = cursor.getDouble(cursor
.getColumnIndex("price"));
Log.d("MainActivity", "book name is " + name);
Log.d("MainActivity", "book author is " + author);
Log.d("MainActivity", "book pages is " + pages);
Log.d("MainActivity", "book price is " + price);
} while (cursor.moveToNext());
}
cursor.close();
}
});
Button replaceData = (Button) findViewById(R.id.replace_data);
replaceData.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
SQLiteDatabase db = dbHelper.getWritableDatabase();
db.beginTransaction();
try {
db.delete("Book", null, null);
ContentValues values = new ContentValues();
values.put("name", "Game of Thrones");
values.put("author", "George Martin");
values.put("pages", "720");
values.put("price", 20.85);
db.insert("Book", null, values);
db.setTransactionSuccessful();
} catch (Exception e) {
e.printStackTrace();
} finally {
db.endTransaction();
}
}
});
}
@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);
}
}
这其中也包含了事物的使用。比较具体。
Demo下载：http://download.csdn.net/detail/xdwyyan/8077323
原创文章，作者：Maggie-Hunter，如若转载，请注明出处：https://blog.ytso.com/tech/aiops/3267.html