diff options
Diffstat (limited to 'libpqpp/pq-selectcommand.cpp')
-rw-r--r-- | libpqpp/pq-selectcommand.cpp | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/libpqpp/pq-selectcommand.cpp b/libpqpp/pq-selectcommand.cpp new file mode 100644 index 0000000..26967c5 --- /dev/null +++ b/libpqpp/pq-selectcommand.cpp @@ -0,0 +1,113 @@ +#include "pq-selectcommand.h" +#include "pq-connection.h" +#include "pq-column.h" +#include "pq-error.h" + +PQ::SelectCommand::SelectCommand(const Connection * conn, const std::string & sql, unsigned int no) : + DB::Command(sql), + DB::SelectCommand(sql), + PQ::Command(conn, sql, no), + executed(false), + txOpened(false), + nTuples(0), + tuple(0), + fTuples(35), + execRes(NULL), + s_declare(mkdeclare()), + s_fetch(mkfetch()), + s_close(mkclose()) +{ +} + +PQ::SelectCommand::~SelectCommand() +{ + if (txOpened) { + c->commitTx(); + } + if (executed) { + PQclear(PQexec(c->conn, s_close.c_str())); + if (execRes) { + PQclear(execRes); + } + } +} + +std::string +PQ::SelectCommand::mkdeclare() const +{ + std::string psql; + psql.reserve(sql.length() + 40); + psql += "DECLARE "; + psql += stmntName; + psql += " CURSOR FOR "; + prepareSql(psql, sql); + return psql; +} + +std::string +PQ::SelectCommand::mkfetch() const +{ + char buf[BUFSIZ]; + snprintf(buf, sizeof(buf), "FETCH %d IN %s", fTuples, stmntName.c_str()); + return buf; +} + +std::string +PQ::SelectCommand::mkclose() const +{ + char buf[BUFSIZ]; + snprintf(buf, sizeof(buf), "CLOSE %s", stmntName.c_str()); + return buf; +} + +void +PQ::SelectCommand::execute() +{ + if (!executed) { + if (!txOpened) { + c->beginTx(); + txOpened = true; + } + execRes = c->checkResult( + PQexecParams(c->conn, s_declare.c_str(), values.size(), NULL, &values.front(), &lengths.front(), &formats.front(), 0), + PGRES_COMMAND_OK); + fetchTuples(); + unsigned int nFields = PQnfields(execRes); + for (unsigned int f = 0; f < nFields; f += 1) { + insertColumn(DB::ColumnPtr(new Column(this, f))); + } + executed = true; + } +} + +void +PQ::SelectCommand::fetchTuples() +{ + if (execRes) { + PQclear(execRes); + } + execRes = NULL; + execRes = c->checkResult(PQexec(c->conn, s_fetch.c_str()), PGRES_TUPLES_OK); + nTuples = PQntuples(execRes); + tuple = -1; +} + +bool +PQ::SelectCommand::fetch() +{ + execute(); + if ((tuple >= (nTuples - 1)) && (nTuples == fTuples)) { + fetchTuples(); + } + if (tuple++ < (nTuples - 1)) { + return true; + } + else { + PQclear(PQexec(c->conn, s_close.c_str())); + PQclear(execRes); + execRes = NULL; + executed = false; + return false; + } +} + |