classname_autoid_find

This function returns a handle to the object referenced by its autoid.

Prototype

 
    MCO_RET	classname_autoid_find(	/*IN*/ mco_trans_h trans,
                        /*IN*/ autoid_t id
                       /*OUT*/ classname * handle );
 

Arguments

trans	A MCO_READ_WRITE transaction handle returned by mco_trans_start()
id	The autoid value of the object to be located
handle	The address of a variable of type class handle

Description

This function will return a handle to the object referenced by the autoid value in the argument id.

Return Codes

MCO_S_OK	The object was located successfully
MCO_S_NOTFOUND	There are no objects referenced by the autoid value given
MCO_E_TRANSACT	Transaction is in an error state

Example

The following code snippets demonstrate how classname_autoid_find() is used to lookup a database object.

 
 
    Snippet from schema file:
            
     
    class Department
    {
        autoid[1000];
        string name;
        string code;
         
        unique tree<name> Iname;
        unique tree<code> Icode;
    };
 
    class Employee
    {
        string name;
        autoid_t dept;
         
        unique tree<name> Iname;
        unique tree<dept,name> Idept_name;
    };
     
    Application snippet:
            
     
    MCO_RET find_coworkers(mco_db_h db, char * search_name)
    {
        MCO_RET rc = MCO_S_OK;
        mco_trans_h t;
        Employee emp;
        autoid_t dept_id1;
        Department dept1;
         
        /* Find co-workers of search_name */
        rc = mco_trans_start(db, MCO_READ_ONLY, MCO_TRANS_FOREGROUND, &t);
         
        ...
         
        // 1. find employee record by name
        rc = Employee_Iname_find(t, search_name, (uint2)strlen(search_name), &emp);
        if (MCO_S_OK == rc) 
        {
            printf("\n\n%s's co-workers in ", search_name);
            Employee_dept_get(&emp, &dept_id1);
         
            // 2. Find the Department object by its autoid
            rc = Department_autoid_find(t, dept_id1, &dept1);
            
            ...
        }
    }
     
     

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