Hi,
I tried to update bytea field, using prepared statement, and have problem:
There are twice escaped characters stored in database. First esaping cause
"Esc = T.esc_raw(...)", second one cause "I(Esc);"
It is possible pass raw data to prepare::invocation(), to avoid this
behavior ?
Thanks,
Lumir Vanek
KPoGre developer
----------------------------------
Here is my source - slightly modified test062 :
T.exec("DELETE FROM pqxxbin");
const int bufSize = 4;
char buffer1[bufSize]; // some raw data - begin of PNG file
buffer1[0] = 0x89; // \211
buffer1[1] = 0x50; // P
buffer1[2] = 0x4E; // N
buffer1[3] = 0x47; // G
T.exec("CREATE TEMP TABLE pqxxbin (binfield bytea)");
// Make escaped string from buffer data
const std::string Esc = T.esc_raw(reinterpret_cast <const unsigned
char *> (&buffer1), bufSize);
const std::string prepStmtName = "test";
pqxx::prepare::declaration D = m_pConnection->prepare(prepStmtName,
"INSERT INTO pqxxbin VALUES ($1)");
D("bytea", pqxx::prepare::treat_binary);
prepare::invocation I = T.prepared(prepStmtName);
I(Esc); // pass escaped string as invocation parameter for $1. But
this cause escaping twice !
I.exec();
result R = T.exec("SELECT binfield from pqxxbin");
binarystring B( R.at(0).at(0) );
if (B.empty())
cout << "Binary string became empty in conversion" << endl;
cout << "original: 211PNG" << endl << "returned: " << B.c_ptr() << endl;
if (B.size() != bufSize)
cout << "Binary string got changed from " + to_string(bufSize) +
" to " + to_string(B.size()) + " bytes" << endl;
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