使用C ++和OCCI在CLOB中编写

Question

I'm developing a C++ application that populates an Oracle (11g) database. This database has a package with the following signature:

FUNCTION SAVE_CONF
(I_USER IN VARCHAR2
,I_APP IN VARCHAR2
,I_CONTEXT IN VARCHAR2
,O_CFG OUT SYS_REFCURSOR  --CLOB
,O_ERROR_MSG OUT VARCHAR2
)
RETURN NUMBER;

However, i cannot access the O_CFG refcursor in my application. This is how I define my SQL statement.

OraStmt->setSQL("BEGIN :1 := SCHM.PCK.SAVE_CONF(:2,:3,:4,:5,:6); END;");
OraStmt->registerOutParam(1, OCCIINT);
OraStmt->setString(2, User.GetBuffer(0));
OraStmt->setString(3, App.GetBuffer(0));
OraStmt->setString(4, Context.GetBuffer(0));         
OraStmt->registerOutParam(5,OCCICLOB);
OraStmt->registerOutParam(6,OCCISTRING,32767);
OraStmt->setAutoCommit(FALSE);

OraStmt->executeQuery(); 

However, I'm not able to define the 5th argument data type. I've already tried to use a OCCICURSOR, a OCCIREF, and many other data types.

When the instruction executeQuery() is performed, an oracle::occi::SQLException is thrown with an ORA-6550. This ORA suggests an argument type mismatch.

I have worked with writing in CLOBs before but never through a REFCURSOR.

Answer 1

After some testing, the solution was to use a ResultSet as intermediate.

OraStmt->setSQL("BEGIN :1 := SCHM.PCK.SAVE_CONF(:2,:3,:4,:5,:6); END;");
OraStmt->registerOutParam(1, OCCIINT);
OraStmt->setString(2, User.GetBuffer(0));
OraStmt->setString(3, App.GetBuffer(0));
OraStmt->setString(4, Context.GetBuffer(0));         
OraStmt->registerOutParam(5,OCCICLOB);
OraStmt->registerOutParam(6,OCCISTRING,32767);
OraStmt->setAutoCommit(FALSE);
OraStmt->executeUpdate(); 
ResultSet   *rs;

rs = OraStmt->getCursor(5);

rs->next();
Clob cLob = rs->getClob(1);

char *pBuffer = static_cast<char *>(Configuration.GetBuffer(0));

int remaining = Configuration.GetLength();
int written = 0;
int pos = 0;

do
{
    written = cLob.writeChunk(remaining, (unsigned char *)&pBuffer[pos], remaining, 1);

    pos += written;
    remaining -= written;
}
while(remaining > 0);

OraStmt->closeResultSet(rs);