每日打卡

今天学习了android stdio数据库的连接：

package com.example.dbproject;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.widget.Toast;
public class DbContect extends SQLiteOpenHelper {
private static final int VERSION=1;
private static final String DBNAME="Users.db"; // 创建数据库名叫 Users
private Context mContext;

public DbContect(Context context){
super(context,DBNAME,null,VERSION);
mContext = context;
}
//创建数据库
public void onCreate(SQLiteDatabase db){
//创建密码表 pwd_tb
db.execSQL("create table pwd_tb (pwd varchar(20) primary key)");
//创建收入表 user_tb
db.execSQL("create table user_tb(_id integer primary key autoincrement, money decimal," +
" time varchar(10),type varchar(10),handler varchar(100),mark varchar(200))");
}
//数据库版本更新
public void onUpgrade(SQLiteDatabase db,int oldVersion,int newVersion)
{
db.execSQL("drop table if exists pwd_tb");
db.execSQL("drop table if exists user_tb");
onCreate(db);
}

}

 问题很多，试了多次没有连接成功。