Android/Database.java

package com.example.picture_share;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.widget.Toast;

import androidx.annotation.Nullable;

public class Database extends SQLiteOpenHelper {

    private static final String dbname="mydb";

    private Context mContext;
   public Database(@Nullable Context context, @Nullable String name, @Nullable SQLiteDatabase.CursorFactory factory, int version) {

        super(context, name, factory, version);
        mContext=context;
    }

    public Database(Context context){
        super(context,"mydb",null,1);
        mContext=context;
    }
    @Override
    public void onCreate(SQLiteDatabase db) {

        //创建一个用户表，包括所有用户，里面有id，密码，用户名和头像
        db.execSQL("create table if not exists users"+
                "(id text primary key," +
                "password text not null,"+
                "name text ,"+
                "touxiang blob)");

        //创建一个图片表，存储图片,图片的id，详细信息，以及发布的用户id和图片
        db.execSQL("create table if not exists picturestable"+
                "(idnum text ,"+
                "details text,"+
                "usrerid text,"+
                "pictures blob)");
        //创建一个收藏点赞表，存放图片id，个人账号
        db.execSQL("create table if not exists personlikes"+
                "(idnum text ,"+
                "usrerid text)");
        Toast.makeText(mContext,"数据库创建成功", Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

    }
}