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SQLite数据库
个人学习，仅供参考：
layout部分：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:orientation="vertical"
tools:context="com.example.administrator.mysqlite2.MainActivity">
<EditText
android:id="@+id/username"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="25sp"
android:background="@color/colorPrimary"
/>
<EditText
android:id="@+id/password"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="25sp"
android:background="@color/colorAccent"/>
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="25sp"
android:layout_marginTop="30dp"
android:text="注册"
android:onClick="addUser"
android:background="@drawable/shape"/>
<Button
android:id="@+id/del"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="25sp"
android:layout_marginTop="30dp"
android:text="删除"
android:onClick="del"
android:background="@drawable/shape"/>
<Button
android:id="@+id/update"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="25sp"
android:layout_marginTop="30dp"
android:text="更新"
android:onClick="update"
android:background="@drawable/shape"/>
<Button
android:id="@+id/query"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="25sp"
android:layout_marginTop="30dp"
android:text="查询"
android:onClick="query"
android:background="@drawable/shape"/>
</LinearLayout>
控件附加部分：
model类部分：
创建数据库部分：
package com.example.administrator.mysqlite2;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
/**
* 构造方法
* @param context：上下文
// * @param name：数据库名称
// * @param factory：游标工厂，默认为null
// * @param version:数据库版本号，大于等于1
*/
public class MyDatabaseSqlite extends SQLiteOpenHelper {
public MyDatabaseSqlite(Context context) {
super(context, "user2.db", null , 3);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("create table userLiang(id integer primary key autoincrement,name varchar(20),password varchar(20))");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("alter table userLiang add sex varchar(20)");
}
}
---------------------
对数据库的增删改查方法：SQLDate
package com.example.administrator.mysqlite2;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
/**
* Created by Administrator on 2017/1/4.
*/
public class SQLDate {
private MyDatabaseSqlite databaseSqlite;
public SQLDate(Context context) {
databaseSqlite=new MyDatabaseSqlite(context);
}
//第一种方法
/* public void add(String name,String password){
//对数据库进行读操作
SQLiteDatabase db=databaseSqlite.getWritableDatabase();
db.execSQL("insert into userLiang(name,password)Values(?,?)",new Object[]{name,password});
}*/
/* //第二种添加数据方法
public void add(String name,String password){
SQLiteDatabase db=databaseSqlite.getWritableDatabase();
//盛放数据的集合
ContentValues cv=new ContentValues();
cv.put("name",name);
cv.put("password",password);
db.insert("userLiang",null,cv);
db.close();
}*/
//第三种方式添加数据
public void add(UserModel model){
SQLiteDatabase db=databaseSqlite.getWritableDatabase();
//向数据库中添加数据
db.execSQL("insert into userLiang(name,password)Values(?,?)",new Object[]{model.getName(),model.getPassword()});
}
//删
/* public void delete(String name){
SQLiteDatabase db=databaseSqlite.getWritableDatabase();
//删除数据
db.execSQL("delete from userLiang where name=?",new Object[]{name});
}*/
public void delete(String name){
SQLiteDatabase db=databaseSqlite.getWritableDatabase();
//删除数据
db.delete("user2","name=?",new String[]{name});
}
//改
/*public void update(String name,String password){
SQLiteDatabase db=databaseSqlite.getWritableDatabase();
db.execSQL("update userLiang set password=? where name=?",new Object[]{password,name});
}*/
public void update(String name,String password){
SQLiteDatabase db=databaseSqlite.getWritableDatabase();
ContentValues cv=new ContentValues();
cv.put("name",name);
cv.put("password",password);
db.update("user2",cv,"name=?",new String[]{name});
db.close();
}
//查
public boolean quary(String name,String password){
SQLiteDatabase db=databaseSqlite.getWritableDatabase();
//查找数据
Cursor cursor=db.rawQuery("select * from userLiang where name=? and password=?",new String[]{name,password});
if(cursor.moveToFirst()==true){
cursor.close();
return true;
}
return false;
}
}
--------------------
activity类：对数据的增删改查实现
package com.example.administrator.mysqlite2;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;
import static com.example.administrator.mysqlite2.R.id.username;
public class MainActivity extends AppCompatActivity {
private MyDatabaseSqlite myDatabaseSqlite;
private EditText name;
private EditText password;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
name= (EditText) findViewById(username);
password= (EditText) findViewById(R.id.password);
//初始化数据库
// myDatabaseSqlite=new MyDatabaseSqlite(this);
//获取数据库读写权限
// SQLiteDatabase sqLiteDatabase=myDatabaseSqlite.getWritableDatabase();
/* //获取数据库的只读权限
SQLiteDatabase sqLiteDatabase1=myDatabaseSqlite.getReadableDatabase();*/
}
//第二种
/* public void addUser(View view){
SQLDate modelDate=new SQLDate(this);
String name1= name.getText().toString();
String pass=password.getText().toString();
modelDate.add(name1,pass);
}*/
//第三种
public void addUser(View view){
SQLDate model=new SQLDate(this);
UserModel userModel=new UserModel();
String name1=name.getText().toString();
String pass=password.getText().toString();
userModel.setName(name1);
userModel.setPassword(pass);
model.add(userModel);
}
//删除数据1
public void del(View view){
SQLDate model=new SQLDate(this);
model.delete("liangli");
}
//更新数据
public void update(View view){
SQLDate model=new SQLDate(this);
model.update("second","aaa");
}
//查询数据
public void query(View view){
SQLDate model=new SQLDate(this);
String username=name.getText().toString();
String pass=password.getText().toString();
boolean flag=model.quary(username,pass);
if(flag==true){
Toast.makeText(this,"已找到",Toast.LENGTH_SHORT).show();
}else {
Toast.makeText(this,"未找到",Toast.LENGTH_SHORT).show();
}
}
}
SQLite数据库