Hi everyone,
I use soci with sqlite3 backend and have some really nasty problem that has
been bugging me for days. In short, my application autogenerates a high-level
OOP/ORM interface for my SQLite DB. This interface uses soci internally. In one
table, I store a timestamp coming from boost::posix_time::ptime into the
database. I convert the value as follows:
template<> struct type_conversion<boost::posix_time::ptime> {
typedef int base_type;
static void from_base(const int& t, indicator& i, boost::posix_time::ptime&
target) {
target = Helper::Time::timeFrom(t);
}
static void to_base(const boost::posix_time::ptime& d, int& target,
indicator& i) {
target = Helper::Time::secondsSinceEpoch(d);
i = i_ok;
}
};
(Helper::Time converts the timestamp into seconds since 1.1.1970 and back)
Writing a row into the DB looks like this:
soci::session sql(Connetion::pool);
sql << "INSERT INTO " << NAME << " (REP_TIMESTAMP, REP_EVENT, REP_LTU_ID,
REP_SEC_ID) VALUES (:timestamp, :event, :ltuId, :secId)",
use (bo.timestamp),
use (bo.event),
use (bo.ltuId),
use (bo.secId);
What happens is that bo.timestamp (which is a boost::posix_time::ptime)
sometimes gets inserted as string, not as int. This leads to std::bad_cast()
when I try to load from the DB. I already asked on Stackoverflow, someone told
me there that SQLite has dynamic typing and it's perfectly possible to insert a
string into a numeric column. However, I would expect that this code always
inserts the value as integer.
I didn't find any way to reliably reproduce the problem. It just sometimes
happens that a string gets written into the DB. May it be that this is a
problem on the soci side? Is it possible that a value changes its type before
it gets inserted? How can I further debug this? As for now, I can only notice
the problem when I reload the row. Is there a way to hook into soci and check
for the correct data types before inserting, so I can at least track down the
origin of the problem?
Thanks,
Felix
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