如何清理/删除greenDao数据库

问题描述

目前我正在这样做:

DaoMaster.dropAllTables(getDb(), true);
DaoMaster.createAllTables(getDb(), true);

但是，当我尝试向数据库中添加实体时，我收到崩溃日志，指出该表不存在

but then, when I'm trying to add entity to the database, I'm getting crash log saying that this table isn't exist

我知道发生这种情况是因为数据库已锁定并且尚未创建表.因此，我将这个问题简化为问题-如何知道表是否在grrenDao/Sqlite中锁定了?

I know that it happens because the db is locked and tables wasn't created yet. So I'm reducing this problem to the problem - how to know if the tables are locked in grrenDao/Sqlite?

推荐答案

直到现在，我都不担心表是否被锁定；就我而言，我可以执行以下操作，并且可以正常工作:

Until now, I don't worry if tables are locked or not; in my case, i do the following and it works:

首先，当执行App.onCreate时，我将进行标准初始化.

First, when App.onCreate executes, I make the standard initializations.

    T.devOpenHelper= new DaoMaster.DevOpenHelper(context, "mydatabase", null);
    T.sqLiteDatabase= T.devOpenHelper.getWritableDatabase();
    T.daoMaster= new DaoMaster(T.sqLiteDatabase);
    T.daoSession= T.daoMaster.newSession();
    T.dao_myEntity= T.daoSession.getMyEntityDao();

将来，我会像您一样删除并重新创建所有表:

In some moment in the future I drop and recreate all tables, just like you:

    T.daoMaster.dropAllTables(T.sqLiteDatabase, true);
    T.daoMaster.createAllTables(T.sqLiteDatabase, true);

但就我而言，那么我可以立即插入一个新实体:

But in my case, then I can immediately insert a new entity:

    MyEntity e= new MyEntity();
    e.setId_ticket(1L);
    e.setDescription("wololo");
    long id= T.dao_myEntity.insert(e);
    Log.d(G.tag, "T.erase_all: id: " + id); // prints "T.erase_all: id: 1"

希望对您有帮助.

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