Example: Displaying Attributes of an OMetaData Object

This example recursively displays all attributes belonging to a table.

Note: For more information about sample code, see Sample Code and Applications.

#include <iostream.h>

#include "oracl.h"

// This code recursively displays all attributes belonging to

// an OMetaData object

void RecursiveDescribe(const char *name, OMetaData *pOMD)

{

OMDAttribute pOMDAttr;

OMetaData pOMD1;

int count = pOMD->GetCount();

for (int i = 0; i<count; i++) {

pOMDAttr = pOMD->GetAttribute(i);

// If an attribute can be described further, describe it,

// otherwise dump its attribute name & value

if (pOMDAttr.IsMDObject()) {

pOMD1 = pOMDAttr.GetValue();

RecursiveDescribe(pOMDAttr.GetName(), &pOMD1);

} else {

cout << name << "->" << pOMDAttr.GetName() << " = " << (const char *)pOMDAttr.GetValue() << endl;

}

}

}

int main()

{

// Initialize the C++ Class Library before use.

// Usually initialization is done at the beginning of the program.

OStartup();

// Construct a database, obtaining a database connection:

ODatabase odb("ExampleDB", "scott", "tiger");

// The Odatabase object (odb) allows you to connect to a database

// ("ExampleDB") along with other connection information, and

// sets you up to execute SQL statements.

// Using the Describe() method of ODatabase, we can get metadata

// info for a schema object

OMetaData omd = odb.Describe("emp");

/* OMetaData can be also constructed as the following:

OMetaData omd;

omd.Open(odb, "emp");

*/

// Call a simple method to get the metadata type, see the

// GetType method for all possible types.

cout << "EMP is of the type " << omd.GetType() << endl;

// Call simple methods to retrieve an attribute name and value

cout << "EMP's first attribute: " << omd.GetAttrName(0) << " = " << (const char *)omd.GetAttrValue(0) << endl;

cout << endl;

// The following dumps out all metadata information

RecursiveDescribe("emp", &omd);

// Uninitialize the C++ Class Library when you are finished with it.

// Usually uninitialization is done at the end of the program.

OShutdown();

return 0;

}