我有数据库examguide，我已经创建了一个表table_subject，现在
我想在此数据库中创建第二个表 (table_chapter)。我的问题是如何将此表添加到现有数据库中？我有以下代码。任何帮助表示赞赏。

private static final String DATABASE_CREATE = "create table IF NOT EXISTS "
        + TABLE_SUBJECT + "( " + COLUMN_ID
        + " integer primary key autoincrement, " 
        + COLUMN_SUBJECT + " text not null, "
        + COLUMN_CHAPTER + " text, "
        + COLUMN_QUESTION + " text not null,"
        + COLUMN_OPTIONA + " text not null,"
        + COLUMN_OPTIONB + " text not null,"
        + COLUMN_OPTIONC + " text not null,"
        + COLUMN_OPTIOND + " text not null,"
        + COLUMN_CORRECT + " text not null,"
        + COLUMN_CONFIRM + " text not null);";

    private static final String DATABASE_CREATE1 = "create table IF NOT EXISTS "
    + TABLE_CHAPTER + "( " + COLUMN_ID
    + " integer primary key autoincrement, " 
    + COLUMN_SUBJECT + " text not null, "
    + COLUMN_CHAPTER + " text, "
    + COLUMN_QUESTION + " text not null,"
    + COLUMN_OPTIONA + " text not null,"
    + COLUMN_OPTIONB + " text not null,"
    + COLUMN_OPTIONC + " text not null,"
    + COLUMN_OPTIOND + " text not null,"
    + COLUMN_CORRECT + " text not null,"
    + COLUMN_CONFIRM + " text not null);";

public MySQLiteHelper open() throws SQLException 
{
    db = this.getWritableDatabase();
    return this;
}

public MySQLiteHelper(Context context)
{
    super(context, DATABASE_NAME, null, DATABASE_VERSION);

}


@Override
public void onCreate(SQLiteDatabase database) {

    database.execSQL(DATABASE_CREATE);
    database.execSQL(DATABASE_CREATE1);

}

此代码不创建第二个表。我想要我的数据库中的两个表。
它在 logcat 中显示以下错误。

03-21 18:31:06.551: ERROR/Database(8255): Error inserting chapter=paging correctoption=shadow copy craete a duplicate copy of page subject=operating system question=what is shadow copy? optiona=shadow copy craete a duplicate copy of page confirm=YES optionb=sahdow copy create paging  optionc=shadow copy delete duplicate page optiond=shadow copy delete original and create shadow copy
03-21 18:31:06.551: ERROR/Database(8255): android.database.sqlite.SQLiteException: no such table: chapter: , while compiling: INSERT INTO chapter(chapter, correctoption, subject, question, optiona, confirm, optionb, optionc, optiond) VALUES(?, ?, ?, ?, ?, ?, ?, ?, ?);
03-21 18:31:06.551: ERROR/Database(8255):     at android.database.sqlite.SQLiteCompiledSql.native_compile(Native Method)
03-21 18:31:06.551: ERROR/Database(8255):     at android.database.sqlite.SQLiteCompiledSql.compile(SQLiteCompiledSql.java:92)
03-21 18:31:06.551: ERROR/Database(8255):     at   android.database.sqlite.SQLiteCompiledSql.<init>(SQLiteCompiledSql.java:65)
03-21 18:31:06.551: ERROR/Database(8255):     at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:83)
03-21 18:31:06.551: ERROR/Database(8255):     at android.database.sqlite.SQLiteStatement.<init>(SQLiteStatement.java:41)
03-21 18:31:06.551: ERROR/Database(8255):     at android.database.sqlite.SQLiteDatabase.compileStatement(SQLiteDatabase.java:1149)
03-21 18:31:06.551: ERROR/Database(8255):     at android.database.sqlite.SQLiteDatabase.insertWithOnConflict(SQLiteDatabase.java:1569)
03-21 18:31:06.551: ERROR/Database(8255):     at android.database.sqlite.SQLiteDatabase.insert(SQLiteDatabase.java:1426)
03-21 18:31:06.551: ERROR/Database(8255):     at com.example.examguide.MySQLiteHelper.insertChapterData(MySQLiteHelper.java:212)
03-21 18:31:06.551: ERROR/Database(8255):     at com.example.examguide.ObjectiveAddActivity$2.onClick(ObjectiveAddActivity.java:155)

最佳答案

制作另一个 CREATE TABLE 字符串，然后在您的 onCreate 中，再次调用 execSQL:

database.execSQL(DATABASE_CREATE1);
database.execSQL(DATABASE_CREATE2);

编辑

要将另一个表添加到现有数据库，请按如下方式修改您的 onUpgrade 方法。 onUpgrade 在数据库需要升级时被调用；请注意，您必须增加 VERSION_NUMBER(您希望将其作为私有(private)实例变量包含在您的类中)才能生效。

@Override
public void onUpgrade (SQLiteDatabase db, int oldVersion, int newVersion) {
    db.executeSQL(DATABASE_CREATE2);
}

关于java - 如何在sqlite数据库中添加第二个表？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/9804083/