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FMDatabaseQueueiOSアプリケーションで使用しています。キューの作成時に値を返す方法を理解するのに行き詰まっています。あなたの助けに感謝！！

 FMDatabaseQueue *queue = [FMDatabaseQueue databaseQueueWithPath:aPath]; 

[queue inDatabase:^(FMDatabase *db) {
[db executeUpdate:@"INSERT INTO myTable VALUES (?)", [NSNumber numberWithInt:1]];
[db executeUpdate:@"INSERT INTO myTable VALUES (?)", [NSNumber numberWithInt:2]];
[db executeUpdate:@"INSERT INTO myTable VALUES (?)", [NSNumber numberWithInt:3]];

FMResultSet *rs = [db executeQuery:@"select * from foo"];
while ([rs next]) {
    ... 
}
// I want value to be returned from here
}];
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2 に答える 2

0

以下の例のように、ブロックメソッドで別のものを渡すことができます

FMDB の Github ページページを読めば、仕組みがわかるかもしれません。

[queue inTransaction:^(FMDatabase *db, BOOL *rollback) {
    [db executeUpdate:@"INSERT INTO myTable VALUES (?)", [NSNumber numberWithInt:1]];
    [db executeUpdate:@"INSERT INTO myTable VALUES (?)", [NSNumber numberWithInt:2]];
    [db executeUpdate:@"INSERT INTO myTable VALUES (?)", [NSNumber numberWithInt:3]];

    if (whoopsSomethingWrongHappened) {
        *rollback = YES;
        return;
    }
    // etc…
    [db executeUpdate:@"INSERT INTO myTable VALUES (?)", [NSNumber numberWithInt:4]];
}]; 






 FMDatabaseQueue will run the blocks on a serialized queue 
(hence the name of the class). So if you call FMDatabaseQueue's 
methods from multiple threads at the same time, they 
will be executed in the order they are received. 
This way queries and updates won't step on each other's toes,
 and every one is happy.

    Note: The calls to FMDatabaseQueue's methods are blocking. So even though you are passing along blocks, they will not be run on another thread.
于 2013-05-27T04:22:00.100 に答える