传递＆＃39; sqlite3 * const *＆＃39; （又名＆＃39; struct sqlite3 * const *＆＃39;）参数类型＆＃39; sqlite3 **＆＃39; （又名＆＃39; struct sqlite3 **＆＃39;）丢弃限定词

Question

我在使用数据库sqlite时出现警告消息。它出现在＆＃34;＆amp;数据库＆＃34; 上 有什么想法吗？

 sqlite3 *database;

NSLog(@"Open Database : %@", path);

            // Open the database. The database was prepared outside the application.
            if (sqlite3_open([path UTF8String], &database) == SQLITE_OK)
            {
                NSLog(@"Open Database OK");


                NSString *selectSQL = [NSString stringWithFormat:@"....

Answer 1

答案：这是因为我把数据库的声明放在发货之外。

这是我的旧代码比楼上更完整：

sqlite3 *database;
NSString *path = [[self documentsDirectory] stringByAppendingPathComponent:@"tva.sqlite"];

dispatch_queue_t searchTVAQueue = dispatch_queue_create("searchTVA", NULL);
        dispatch_async(searchTVAQueue, ^{
NSLog(@"Open Database : %@", path);

            if (sqlite3_open([path UTF8String], &database) == SQLITE_OK)
            {
                NSLog(@"Open Database OK");

                NSString *selectSQL = [NSString stringWithFormat:@"....
                ...

这是一个很好的代码：

dispatch_queue_t searchTVAQueue = dispatch_queue_create("searchTVA", NULL);
        dispatch_async(searchTVAQueue, ^{

sqlite3 *database;
NSString *path = [[self documentsDirectory] stringByAppendingPathComponent:@"tva.sqlite"];

NSLog(@"Open Database : %@", path);

            if (sqlite3_open([path UTF8String], &database) == SQLITE_OK)
            {
                NSLog(@"Open Database OK");

                NSString *selectSQL = [NSString stringWithFormat:@"....
                ...

我只是将数据库声明直接包含在dispatch_async中。