ios - 乱序调用的 SQLite3 库例程

Question

下面的代码给了我一个乱序调用的库例程错误，但我无法解释问题出在哪里。有任何想法吗 ？

- (BOOL)insertProduct:(Product *)product inOrder:(Order *)order withAmount:(int)amount
    {
        BOOL ok = NO;
        sqlite3_stmt *statement;

        const char *dbpath = [_databasePath UTF8String];

        if (sqlite3_open(dbpath, &_database) == SQLITE_OK)
        {
            NSString * insertSQL;
            int amount = [self getAmountForProduct:product inOrder:order];
            NSLog(@"%i", amount);

            if (amount != -1)
            {
                insertSQL = [NSString stringWithFormat: @"UPDATE ARTICOLIPERORDINE SET quantita = %i WHERE ordine = %i AND articolo = '%@'", amount, order.idOrdine, product.codice];
            }
            else
            {
                insertSQL = [NSString stringWithFormat: @"INSERT INTO ARTICOLIPERORDINE (ordine, articolo, quantita) VALUES(%i, '%@', %i)",order.idOrdine, product.codice, 1];
            }

            NSLog(@"%@", insertSQL);
            const char *insert_stmt = [insertSQL UTF8String];

            if (sqlite3_prepare_v2(_database, insert_stmt, -1, &statement, NULL) == SQLITE_OK)
            {
                if (sqlite3_step(statement) == SQLITE_DONE)
                {
                    ok = YES;
                }
                else
                {
                    ok = NO;
                    NSLog(@"sqlite3 ERROR %s: %@",sqlite3_errmsg(_database), insertSQL);
                }

                sqlite3_finalize(statement);
                sqlite3_close(_database);
            }
            else
            {
                NSLog(@"Error prepare = %s", sqlite3_errmsg(_database));
            }

        }

        return ok;
    }

日志打印错误准备=库例程调用顺序不对

Answer 1

我有一种方法。在此之前，请确保您已完成所有 sql 查询，如连接打开、关闭、完成等。

Before run your query actual into your code, execute that query into any database browser, You will see what is missing in your query.

在我的例子中，我错误地将列名放入查询中并运行代码，我多次遇到错误。我仔细检查了所有代码并在数据库浏览器中执行查询，我发现了我的错误。