android - 如何将现有的 sqlite 表迁移到具有 VARCHAR、TIMESTAMP 等数据类型的 ROOM Db？

Question

在我的旧 sqlite 表中，我有这些列 (id INTEGER PRIMARY KEY AUTOINCREMENT,api_response_json TEXT, api_req TEXT,post_params TEXT,req_type VARCHAR,timestamp TIMESTAMP)

现在我正在尝试像这样将它迁移到 Room DB:-

static final Migration MIGRATION_1_2 = new Migration(1, 2) {

    @Override
    public void migrate(SupportSQLiteDatabase database) {
    // Create the new table
        database.execSQL(
                "CREATE TABLE users_new (id INTEGER PRIMARY KEY AUTOINCREMENT,api_response_json TEXT, api_req TEXT,post_params TEXT,req_type VARCHAR,timestamp TIMESTAMP)");
    // Copy the data
        database.execSQL("INSERT INTO users_new (id,api_response_json, api_req,post_params,req_type,timestamp) "
                + "SELECT id,api_response_json, api_req,post_params, req_type,timestamp "
                + "FROM old_Table_name");
    // Remove the old table
        database.execSQL("DROP TABLE old_Table_name");
    // Change the table name to the correct one
        database.execSQL("ALTER TABLE users_new RENAME TO old_Table_name");}
};

我收到一个错误，迁移没有正确处理

预期: TableInfo{name='api_data', columns={timestamp=Column{name='timestamp', type='TEXT', notNull=false, primaryKeyPosition=0}, req_type=Column{name='req_type', type='TEXT ', notNull=false, primaryKeyPosition=0}, post_params=Column{name='post_params', type='TEXT', notNull=false, primaryKeyPosition=0}, id=Column{name='id', type='INTEGER ', notNull=false, primaryKeyPosition=1}, api_response_json=Column{name='api_response_json', type='TEXT', notNull=false, primaryKeyPosition=0}, api_req=Column{name='api_req', type='TEXT ', notNull=false, primaryKeyPosition=0}}, foreignKeys=[], indices=[]}

发现: TableInfo{name='api_data', columns={timestamp=Column{name='timestamp', type='TIMESTAMP', notNull=false, primaryKeyPosition=0}, req_type=Column{name='req_type', type='VARCHAR ', notNull=false, primaryKeyPosition=0}, post_params=Column{name='post_params', type='TEXT', notNull=false, primaryKeyPosition=0}, id=Column{name='id', type='INTEGER ', notNull=false, primaryKeyPosition=1}, api_response_json=Column{name='api_response_json', type='TEXT', notNull=false, primaryKeyPosition=0}, api_req=Column{name='api_req', type='TEXT ', notNull=false, primaryKeyPosition=0}}, foreignKeys=[], indices=[]}

TIMESTAMP 和 VARCHAR 有问题。

Answer 1

是的，TIMESTAMP 和 VARCHAR 有问题你应该把它改成:

    static final Migration MIGRATION_1_2 = new Migration(1, 2) {
    @Override
    public void migrate(SupportSQLiteDatabase database) {
        // Create the new table
        database.execSQL(
                "CREATE TABLE users_new (id INTEGER PRIMARY KEY AUTOINCREMENT,api_response_json TEXT, api_req TEXT,post_params TEXT,req_type TEXT,timestamp TEXT)");
        // Copy the data
        database.execSQL("INSERT INTO users_new (id,api_response_json, api_req,post_params,req_type,timestamp) "
                + "SELECT id,api_response_json, api_req,post_params, req_type,timestamp "
                + "FROM old_Table_name");
        // Remove the old table
        database.execSQL("DROP TABLE old_Table_name");
        // Change the table name to the correct one
        database.execSQL("ALTER TABLE users_new RENAME TO old_Table_name");}
    };

答案在你的迁移错误中