Android数据库表 _数据库

【Android数据库表】沉舟侧畔千帆进，病树前头万木春。这篇文章主要讲述Android数据库表相关的知识，希望能为你提供帮助。

package com.example.ccc; import android.content.Context; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteDatabase.CursorFactory; import android.database.sqlite.SQLiteOpenHelper; public class StuOpenHelper extends SQLiteOpenHelper{ public StuOpenHelper(Context context) { super(context, "stu.db", null, 5); // TODO Auto-generated constructor stub } @Override public void onCreate(SQLiteDatabase db) { System.out.println("第一次创建"); String sql = "CREATE TABLE stu (_id integer PRIMARY KEY AUTOINCREMENT,USERNAME VARCHAR(20),PASSWORDVARCHAR(20))"; db.execSQL(sql); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { // TODO Auto-generated method stub System.out.println("更新"+oldVersion+""+newVersion); if(oldVersion==5 & & newVersion==6) { String sql = "CREATE TABLE bj (_id integer PRIMARY KEY AUTOINCREMENT,CLASSNAME VARCHAR(20))"; db.execSQL(sql); } } }

package com.example.ccc; import android.content.ContentValues; import android.os.Bundle; import android.app.Activity; import android.database.sqlite.SQLiteDatabase; import android.view.Menu; import android.view.View; import android.widget.EditText; public class MainActivity extends Activity { private String username; private String password; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); } public void click(View view){ username =((EditText) findViewById(R.id.et1)).getText().toString(); password =((EditText) findViewById(R.id.et2)).getText().toString(); StuOpenHelper helper = new StuOpenHelper(this); SQLiteDatabase db =helper.getReadableDatabase(); ContentValues cv = new ContentValues(); cv.put("username",username); cv.put("password",password); db.insert("stu",null,cv); db.close(); } }

< ?xml version="1.0" encoding="utf-8"?> < RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity"> < TextView android:id="@+id/tv1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="用户名：" android:textSize="30dp" android:layout_marginTop="60dp" /> < EditText android:id="@+id/et1" android:layout_width="600dp" android:layout_height="wrap_content" android:layout_toRightOf="@+id/tv1" android:layout_marginTop="50dp" android:textSize="30dp" /> < TextView android:id="@+id/tv2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="密码：" android:textSize="30dp" android:layout_marginTop="50dp" android:layout_below="@+id/tv1" /> < EditText android:id="@+id/et2" android:layout_width="600dp" android:layout_height="wrap_content" android:layout_toRightOf="@+id/tv2" android:layout_marginTop="30dp" android:textSize="30dp" android:layout_below="@+id/et1"/> < Button android:layout_marginTop="80dp" android:layout_width="300dp" android:layout_height="wrap_content" android:text="注册" android:textSize="50dp" android:layout_below="@+id/et2" android:layout_centerHorizontal="true" android:onClick="click" /> < /RelativeLayout>