mco_uda_length

原型

    MCO_RET mco_uda_length(	/*IN*/ mco_uda_object_handle_t * obj,
                  /*IN*/ unsigned short field_no, 
                  /*OUT*/ unsigned short * dimension);

参数

obj	包含 UDA 对象的结构的地址mco_uda_object_handle_t
field_no	字段编号（必须介于 0 到 - 1 之间）struct_info.field_count
dimension	用于接收向量或数组的长度（元素数）的变量的地址

描述

返回 vector 或 array 字段的长度（元素数）。

返回

MCO_S_OK	已成功返回游标
MCO_E_UDA_FIELD_NOT_FOUND	无效field_no
MCO_E_UDA_SCALAR	字段不是向量或数组

示例

    /*  应用程序代码片段 */
        
     
    int main(int argc, char** argv)
    {
        MCO_RET rc;
        mco_db_h db;
        mco_trans_h t;
        mco_cursor_t cursor;
        unsigned short field_no = 1;
        unsigned short struct_no = 1;
        unsigned short index_no = 5;
        unsigned short length;
        ...
         
        rc = mco_trans_start(db, MCO_READ_ONLY, MCO_TRANS_FOREGROUND, &t);
        if ( MCO_S_OK == rc )
        {
            rc = mco_uda_cursor(t, struct_no, index_no, &cursor);
            for ( ; rc == MCO_S_OK; rc = mco_cursor_next(t, &cursor))
            {
                mco_uda_object_handle_t obj;
                /* get object handle */
                mco_uda_length(&obj, field_no, &length);
        
                ...
            }
            rc = mco_trans_rollback(t);
        }
    }