ToC path:

classname_delete

This function deletes a database object (referenced by its class handle).

Prototype

 
    MCO_RET	classname_delete(	/*IN*/ classname * handle );

Arguments

handle The address of a variable of type class handle

Description

This function will remove the object referenced by handle, and all of the object’s versions, from the database. Hash and tree index entries, if any, will also be removed.

Return Codes

MCO_S_OK	The instance was deleted successfully
MCO_E_ACCESS	The transaction handle is `MCO_READ_ONLY`
MCO_E_TRANSACT	Transaction is in error state
MCO_E_DELETED	This object has been deleted
MCO_E_NOMEM	Database memory allocation error
MCO_ERR_OBJECT_HANDLE	Invalid object handle
MCO_ERR_TRN	Error in the enclosing transaction

Example

The following code snippets demonstrate how classname_delete() is used to delete a database object.

 
    Snippet from schema file:
        
 
    class Record
    {
        uint4 key;
         
        hash <key> hkey;
    };
     
    Application snippet:
        
     
    int find_delete(mco_db_h db, int hkey_val)
    {
        MCO_RET rc;
        mco_trans_h t;
        Record obj;
         
        rc = mco_trans_start(db, MCO_READ_WRITE, MCO_TRANS_FOREGROUND, &t);
        if ( MCO_S_OK == rc ) 
        {
            rc = Record_hkey_find(t, hkey_val, &obj);
            if ( MCO_S_OK == rc )
             {
                rc = Record_delete(&obj);
        
            }
            rc = mco_trans_commit(t);
        }
    }