SQLite数据库崩溃我的应用程序

时间:2017-07-07 15:27:54

标签: java android sqlite android-sqlite sqldatareader

我正在尝试使用android studio创建一个项目,如以下视频: Source 1Source 2 这是我添加的java类中的代码:

    package com.example.asus.androidsqlitedatabase_1;
    import android.content.Context;
    import android.database.sqlite.SQLiteDatabase;
    import android.database.sqlite.SQLiteOpenHelper;

    /**
     * Created by ASUS on 7/6/2017.
     */

    public class Databasehelperclass extends SQLiteOpenHelper {
        public static final String DATABASE_NAME = "Student.db";
        public static final String TABLE_NAME = "Student_table";
        public static final String COLUMN1= "ID";
        public static final String COLUMN2 = "NAME";
        public static final String COLUMN3 = "SURNAME";
        public static final String COLUMN4 = "MARKS";

        public Databasehelperclass(Context context) {
            super(context, DATABASE_NAME, null, 1);
            SQLiteDatabase sqLiteDatabase = this.getWritableDatabase();
        }

        @Override
        public void onCreate(SQLiteDatabase sqLiteDatabase) {
            sqLiteDatabase.execSQL("Create Table" + TABLE_NAME + 
   "(ID INTEGER PRIMARY KEY AUTOINCREMENT,NAME TEXT,SURNAME TEXT,MARKS INTEGER)");}

        @Override
        public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1){
            sqLiteDatabase.execSQL("DROP TABLE IF EXISTS" + TABLE_NAME);
            onCreate(sqLiteDatabase);
        }
    }

这是我在MainActivity.java中的代码

    package com.example.asus.androidsqlitedatabase_1;

    import android.support.v7.app.AppCompatActivity;
    import android.os.Bundle;

    public class MainActivity extends AppCompatActivity {
        Databasehelperclass mydb;

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            mydb = new Databasehelperclass(this);
        }
    }

但是当我使用genymotion将应用程序执行到模拟器时,应用程序停止工作并且无法执行。请有人帮帮我!!

1 个答案:

答案 0 :(得分:1)

问题:查询中的间距错误

解决方案:查询应采用以下格式:

sqLiteDatabase.execSQL("CREATE TABLE " + TABLE_NAME + "("
                + COLUMN1 + " INTEGER PRIMARY KEY AUTOINCREMENT, "
                + COLUMN2 + " TEXT, "
                + COLUMN3 + " TEXT, "
                + COLUMN4 + " INTEGER, "
                + ")";

PS:最好在Query中使用变量名而不是静态列名。

希望有所帮助:)