android - 使用新列更新现有数据库表在 Activity android 中不起作用

Question

我在第一个版本的数据库中有以下模型:

@Table(name = DBConstants.TABLE_CHATS)
public class Chat extends Model {

    @Column(name = DBConstants.COLUMN_CHATS_CHAT_ID,unique = true,onUniqueConflict = Column.ConflictAction.REPLACE)
    public String chatId;

    @Column(name = DBConstants.COLUMN_CHATS_CHAT_MESSAGE)
    public String chatMessage;

    @Column(name = DBConstants.COLUMN_CHATS_SENDER_NAME)
    public String chatSenderName;

    @Column(name = DBConstants.COLUMN_JOBS_JOB_ID)
    public String chatJobId;

    public Chat(){super();}

    public Chat(String chatId, String chatMessage, String chatSenderName, String chatJobId){
        super();
        this.chatId = chatId;
        this.chatMessage = chatMessage;
        this.chatSenderName =chatSenderName;
        this.chatJobId = chatJobId;
    }

    public static List<Chat> getChats(String jobId) {
        return new Select()
                .from(Chat.class)
                .where("jobId=?",jobId)
                .execute();
    }
}

现在我想用新列更新上面的模型，所以我用新列更新了模型类，如下所示。

@Table(name = DBConstants.TABLE_CHATS)
public class Chat extends Model {

    @Column(name = DBConstants.COLUMN_CHATS_CHAT_ID,unique = true,onUniqueConflict = Column.ConflictAction.REPLACE)
    public String chatId;

    @Column(name = DBConstants.COLUMN_CHATS_CHAT_MESSAGE)
    public String chatMessage;

    @Column(name = DBConstants.COLUMN_CHATS_SENDER_NAME)
    public String chatSenderName;

    @Column(name = DBConstants.COLUMN_JOBS_JOB_ID)
    public String chatJobId;

    @Column(name = "extra_column")
    public String extraColumn;

    public Chat(){super();}

    public Chat(String chatId, String chatMessage, String chatSenderName, String chatJobId,String extraColumn){
        super();
        this.chatId = chatId;
        this.chatMessage = chatMessage;
        this.chatSenderName =chatSenderName;
        this.chatJobId = chatJobId;
        this.extraColumn = extraColumn;
    }

    public static List<Chat> getChats(String jobId) {
        return new Select()
                .from(Chat.class)
                .where("jobId=?",jobId)
                .execute();
    }
}

我正在为数据库使用 Active android，所以我完成了以下步骤:

1.更新 list 文件中的数据库版本号

<meta-data android:name="GC_DB_VERSION" android:value="4" />

2.assets/migrations新增4.sql脚本文件

3.在其中添加更新查询。

ALTER TABLE chat ADD COLUMN extra_column TEXT;

1. 现在，当我尝试将新列值插入数据库时​​，出现以下错误:

android.database.sqlite.SQLiteException: table chat has no column named extra_column (code 1): , while compiling: INSERT INTO chat(chat_message,Id,extra_column,chat_sender_name,jobId,chatId) VALUES (?,?,?,?,?,?) 10-16 06:54:29.712 16791-16791/com.example.manikanta.navigationdrawerpattern E/SQLiteDatabase: at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method) 10-16 06:54:29.712 16791-16791/com.example.manikanta.navigationdrawerpattern E/SQLiteDatabase: at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:882) 10-16 06:54:29.712 16791-16791/com.example.manikanta.navigationdrawerpattern E/SQLiteDatabase: at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:493) 10-16 06:54:29.712 16791-16791/com.example.manikanta.navigationdrawerpattern E/SQLiteDatabase: at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588) 10-16 06:54:29.712 16791-16791/com.example.manikanta.navigationdrawerpattern ....... 10-16 06:54:29.712 16791-16791/com.example.manikanta.navigationdrawerpattern E/SQLiteLog: (1) table chat has no column named extra_column

谁能解释一下如何解决这个问题？

Answer 1

我已经解决了。

问题原因:

Activity android 的迁移脚本不会在更改 list 文件中的版本号时被调用

解决方法:

我已经通过 Application.class 使用以下行手动设置数据库版本更改:

Configuration configuration = new Configuration.Builder(this).setDatabaseVersion(13).create();

        ActiveAndroid.initialize(configuration);

我不知道这是否是正确的做法，欢迎任何更好的方法。