classname_new (OID)

This function creates a new instance of a database object with an OID.

Prototype

 
    MCO_RET	classname_new(	/*IN*/ mco_trans_h t, 
                  /*IN*/ dbname_oid *oid,
                  /*OUT*/ classname * handle );
 

Arguments

t	A MCO_READ_WRITE transaction handle returned by mco_trans_start()
oid	The address of a variable of generated typedef dbname_oid which specifies the OID of the object to be allocated
handle	The address of a variable of type class handle

Description

This function will reserve space for a new instance of the class and return a reference to the instance. This form of classname_new() is only valid for classes declared with an OID.

Return Codes

MCO_S_OK	The instance was reserved successfully
MCO_S_DUPLICATE	The OID value is not unique
MCO_E_ACCESS	The transaction handle is MCO_READ_ONLY
MCO_E_TRANSACT	A transaction error occurred
MCO_E_NOMEM	Database memory allocation error

Example

 
     
    Schema snippet:
 
    struct SimpleId
    {
        uint2 id;
    };
    declare oid SimpleId[10000];
     
     
    Application snippet:
     
    const char * dbname = "SimpleDb";
     
    int main(int argc, char* argv[])
    {
        mco_db_h db;
        MCO_RET rc;
        mco_trans_t       t;
        SimpleId simple_id;
        ...
         
        simple_id.id= 99;
        mco_trans_start(db, MCO_READ_WRITE, MCO_TRANS_FOREGROUND, &t);
        if ( MCO_S_OK != rc )
        {
            A a;
            rc = A_new( t, &simple_id, &a );
            
            ...
        }
    }
 

Related Topics