Question

我的项目中已经有两个数据库，并且想要为某个任务创建一个新数据库但是数据库没有创建我认为我在代码中做错了请帮我解决这个问题。感谢。

public class LikeShareDbHelper extends SQLiteOpenHelper{
    static final int version = 10;
    static final String dbName = "LikeShareDB";
    static final String LikeAndShare = "LikeAndShareTable";
    static final String coluId = "id";
    static final String coluTask = "Task_id";
    static final String coluLike = "TLike";
    static final String coluComment = "TComment";
    static final String coluTSahre = "Tshare";
    static final String coluMySelf = "mtself";

    private static final String DATABASE_CREATE = "CREATE TABLE "
            + LikeAndShare + " (" + coluId
            + " INTEGER PRIMARY KEY AUTOINCREMENT, " + coluTask + " TEXT, "
            + coluLike + " TEXT, " + coluComment + " TEXT, " + coluTSahre
            + " Text, " + coluMySelf + " TEXT );";

    SQLiteDatabase db;
    private LikeShareDbHelper dbHelper;

    public LikeShareDbHelper(Context context) {
        super(context, dbName, null, version);
        // TODO Auto-generated constructor stub
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        // TODO Auto-generated method stub
        db.execSQL(DATABASE_CREATE);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // TODO Auto-generated method stub
        db.execSQL("DROP TABLE IF EXISTS " + LikeAndShare);
        onCreate(db);

    }


    public LikeShareDbHelper open() throws SQLException {
        db = dbHelper.getWritableDatabase();
        // dbHelper.open();
        return this;
    }

    // ---closes the database---
    public void close() {
        dbHelper.close();
    }


}

Answer 1

试试这个..对你有帮助

package com.databases;

import java.util.ArrayList;

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

public class DataBaseHelper extends SQLiteOpenHelper {

    Context mContext;

    private static final String DATABASE_NAME = "Personal_Assistant_Chronical.db";
    private static final int DATABASE_VERSION = 1;
    private static final String TABLE_DETAIL = "newContact";

    private static final String COLUMN_PERSON_ID= "personID";
    private static final String COLUMN_PERSON_NAME= "person_name";
    private static final String COLUMN_MOBILE_NUMBER = "mobile_no";
    private static final String COLUMN_LANDLINE_NUMBER = "lanline_no";
    private static final String COLUMN_FAX_NUMBER = "fax_no";
    private static final String COLUMN_EMAIL_ID = "email_id";
    private static final String COLUMN_PERSONAL_ADDRESS = "personal_address";
    private static final String COLUMN_WORK_ADDRESS = "work_address";

    private static final String CREATE_DETAIL_TABLE = "create table if not exists "
            + TABLE_DETAIL
            + "("
            + COLUMN_PERSON_ID
            +" INTEGER primary key autoincrement, "
            + COLUMN_PERSON_NAME
            + " VARCHAR(100) NOT NULL UNIQUE, "
            + COLUMN_MOBILE_NUMBER
            + " VARCHAR(100) NOT NULL , "
            + COLUMN_LANDLINE_NUMBER
            + " VARCHAR(100) NOT NULL, "
            + COLUMN_FAX_NUMBER
            + " VARCHAR(100) NOT NULL, "
            + COLUMN_EMAIL_ID
            + " VARCHAR(100) NOT NULL, "
            + COLUMN_PERSONAL_ADDRESS
            + " VARCHAR(100) NOT NULL, "
            + COLUMN_WORK_ADDRESS
            + " VARCHAR(100) NOT NULL); "
            ;
    private static final String TABLE_PERSONAL = "newPersonal";

    private static final String COLUMN_DATE_ID= "dateID";
    private static final String COLUMN_DATE= "fate";
    private static final String COLUMN_DIARY= "diary";

    private static final String CREATE_PERSONAL_TABLE = "create table if not exists "
            + TABLE_PERSONAL
            + "("
            + COLUMN_DATE_ID
            +" INTEGER primary key autoincrement , "
            + COLUMN_DATE
            +" VARCHAR(100) NOT NULL UNIQUE, "
            + COLUMN_DIARY
            + " VARCHAR(100) NOT NULL); "

            ;   


    public DataBaseHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
        this.mContext=context;
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL(CREATE_DETAIL_TABLE);
        db.execSQL(CREATE_PERSONAL_TABLE);

    }

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

        if (db != null)
            onCreate(db);
    }


        }

Answer 2

请详细说明你的问题。你说“我想”告诉我们数据库没有创建。你检查了什么是100％肯定的？

另外，不要使用“id”而应使用“_id”。它已由BaseColumns._ID为您定义。

Answer 3

private static final String DATABASE_CREATE = "CREATE TABLE "
            + LikeAndShare + " (" + coluId
            + " INTEGER PRIMARY KEY AUTOINCREMENT, " + coluTask + " TEXT, "
            + coluLike + " TEXT, " + coluComment + " TEXT, " + coluTSahre
            + " Text, " + coluMySelf + " TEXT )";

将此代码替换为您的代码。希望它的工作。

Answer 4

通过getWritableDatabase打开数据库时调用数据库onCreate方法....尝试这样做。

数据库不是在sqlite中创建的

4 个答案: