[#CONCPP-96] PreparedStatement SetDouble Drops Significant Digits

Table for testing:

CREATE TABLE `contracts` (

  `cost_as_dbl` decimal(15,4) NOT NULL DEFAULT 0.0000,

  `cost_as_str` varchar(20) NOT NULL

) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4

C++ code for testing:

#include "mariadb/conncpp.hpp"

#include <memory>

int

main()

  sql::Driver* driver = sql::mariadb::get_driver_instance();

  sql::SQLString url("jdbc:mariadb://localhost:3306/*****");

  sql::Properties properties(

    { { "user", "******" }, { "password", "********" } });

   std::unique_ptr<sql::Connection> conn(driver->connect(url, properties));

  double cost(98.765432109);

  std::unique_ptr<sql::PreparedStatement> pstmnt(

    conn->prepareStatement("INSERT INTO contracts (cost_as_dbl, cost_as_str) VALUES (?, ?);"));

  do {

    pstmnt->setDouble(1, cost);

    pstmnt->setString(2, std::to_string(cost));

    pstmnt->executeQuery();

    cost *= 10.0;

  } while (cost < 1000000000);

Query Output:

MariaDB [test]> select * from contracts;

+----------------+------------------+

| cost_as_dbl    | cost_as_str      |

+----------------+------------------+

|        98.7654 | 98.765432        |

|       987.6540 | 987.654321       |

|      9876.5400 | 9876.543211      |

|     98765.4000 | 98765.432109     |

|    987654.0000 | 987654.321090    |

|   9876540.0000 | 9876543.210900   |

|  98765400.0000 | 98765432.109000  |

| 987654000.0000 | 987654321.090000 |

+----------------+------------------+

8 rows in set (0.000 sec)

pstmnt->setDouble only processes the first 6 significant digits and zeros the remaining.

[CONCPP-96] PreparedStatement SetDouble Drops Significant Digits Created: 2022-02-20 Updated: 2022-05-09 Resolved: 2022-05-09
Status:	Closed
Project:	MariaDB Connector/C++
Component/s:	General
Affects Version/s:	1.0.1, 1.1.0
Fix Version/s:	1.0.2, 1.1.2