src/Data/Tools/BizRecord.php
final public function getKeyValue($isUseOldValue = false)
    {
        $keyValue = "";
        foreach ($this->keyFieldColumnMap as $fieldName => $colName) {
            $val = $isUseOldValue ? $this->varValue[$fieldName]->oldValue : $this->varValue[$fieldName]->value;
            if ($keyValue == "")
                $keyValue .= $val;
            else
            // use base64 (a-zA-Z1-9+-) to encode the key and connect them with "#"
                $keyValue .= CK_CONNECTOR . $val;
        }
        return $keyValue;
    }
final public function getKeyValue($isUseOldValue = false)
    {
        $keyValue = "";
        foreach ($this->keyFieldColumnMap as $fieldName => $colName) {
            $val = $isUseOldValue ? $this->varValue[$fieldName]->oldValue : $this->varValue[$fieldName]->value;
            if ($keyValue == "")
                $keyValue .= $val;
            else
            // use base64 (a-zA-Z1-9+-) to encode the key and connect them with "#"
                $keyValue .= CK_CONNECTOR . $val;
        }
        return $keyValue;
    }
Get key (Id) value.
If Id is defined as composite key, the returned key value
is the combination of key columns

@param boolean $isUseOldValue
@return string key field string