I tried debugging the problem. Here is what I found:

If one parameter is passed to the query, the function 'Query::store(const SQLString& str)' is called twice, instead of only once which causes the final query to be: SELECT bpSerialNo FROM rtsBP WHERE bpSerialNo = 'SELECT bpSerialNo FROM rtsBP WHERE bpSerialNo = \'0000000000001001\' Instead of: SELECT bpSerialNo FROM rtsBP WHERE bpSerialNo = '0000000000001001'

I am not familiar with the code and would not know where the root problem lies. Can anybody that is familiar with the query.cpp code help me find the root cause?

Added debug printf's:

--------------------- Result Query::store(const SQLString& str) { printf("Query::store(const SQLString& str): %s, def.size()=%d, def.processing_=%d\n", str.c_str(),def.size(),def.processing_); if ((def.size() == 1) && !def.processing_) { // Take str to be a lone parameter for a template query. The // auto-reset flag is required because we'll end up back in this // function once the query string is built, but we need to take // the 'else' path to avoid an infinite loop. AutoFlag<> af(def.processing_); return store(SQLQueryParms() << str); } else { // Take str to be the entire query string return store(str.c_str(), str.length()); } }

Example:

-------- string m_serial="0000000000001001"; mysqlpp::Query query1 = con->query(); mysqlpp::Result res1; query1 << "SELECT bpSerialNo FROM rtsBP WHERE bpSerialNo = %0q"; query1.parse(); query1.def[0U] = m_serial; cout << query1.preview() << endl; res1 = query1.store(); cout << res1.num_rows() << endl;

Output:

------ SELECT bpSerialNo FROM rtsBP WHERE bpSerialNo = '0000000000001001' Query::store(SQLQueryParms& p) Query::store(const SQLString& str): SELECT bpSerialNo FROM rtsBP WHERE bpSerialNo = '0000000000001001', def.size()=1, def.processing_=0 Query::store(SQLQueryParms& p) Query::store(const SQLString& str): SELECT bpSerialNo FROM rtsBP WHERE bpSerialNo = 'SELECT bpSerialNo FROM rtsBP WHERE bpSerialNo = \'0000000000001001\'', def.size()=1, def.processing_=1 Query::store(const char* str, size_t len): SELECT bpSerialNo FROM rtsBP WHERE bpSerialNo = 'SELECT bpSerialNo FROM rtsBP WHERE bpSerialNo = \'0000000000001001\'' 0

Working example:

---------------- mysqlpp::Query query3 = con->query(); mysqlpp::Result res3; query3 << "SELECT bpSerialNo FROM rtsBP WHERE bpSerialNo = %1q:serial"; query3.parse(); query3.def["serial"] = m_serial; cout << query3.preview() << endl; res3 = query3.store(); cout << res3.num_rows() << endl;

Output:

------- SELECT bpSerialNo FROM rtsBP WHERE bpSerialNo = '0000000000001001' Query::store(SQLQueryParms& p) Query::store(const SQLString& str): SELECT bpSerialNo FROM rtsBP WHERE bpSerialNo = '0000000000001001', def.size()=2, def.processing_=0 Query::store(const char* str, size_t len): SELECT bpSerialNo FROM rtsBP WHERE bpSerialNo = '0000000000001001' 1

Thanks, Roger