将日期时间对象转换为字符串，转换回来

Question

这有点与php中的Access DateTime->date有关，但实际上是别的东西。我有一些从SQL服务器获取DateTime对象的php。我使用 echo $mydate->format('Y-m-d H:i:s'); 所以它只是一个字符串，或者至少我认为它是。（我什至使用显式类型转换来确保）。这是那个代码，

                } else {
                echo "<br/>object ";
                $dt = (string) $row[$column]->format('Y-m-d H:i:s');
                $this->retVal["nonEmpty"] = true;
                $this->retVal["value"] = (string) $dt;
                echo $this->retVal["value"]; //Returns a string, no issue.
                }

当"字符串"从类中传递回时，会出现此问题。

                $convert = new DataConv;
                $convert->conv($newConnectionThree, $fieldNames[$cnt1][$cnt2]["Type"],$fieldNames[$cnt1][$cnt2]["Size"], $tableNames[$cnt1],              $columnNames[$cnt1][$cnt2]);
                $fieldNames[$cnt1][$cnt2]["Type"] = $convert->type;
                $returned = $convert->retVal;
                echo $returned["value"]; //Returns error "Catchable fatal error: Object of class DateTime could not be converted to string".
                var_dump($returned["value"]); //Shows Datetime object. 

现在它又回到了日期时间对象。我认为没有任何理由将其转换回来。我只是想知道是否有人至少对为什么会发生这种情况有答案，但解决方案会有所帮助。除了在课堂之外进行转换之外的任何事情。

Answer 1

我找到了问题所在。这与我的想法无关。无论如何，这是解决方案。

private function get($conn, $table, $column){
    $params = array();
    $expl = array();
    $wrkStrg;
    $tsql = "SELECT [" . $column . "] FROM " . $table;
    $options = array("scrollable" => SQLSRV_CURSOR_KEYSET);
    $getTableData = SQLSRV_QUERY($conn, $tsql, $params, $options);
    if ($getTableData){
    $row = SQLSRV_FETCH_ARRAY($getTableData, SQLSRV_FETCH_ASSOC, SQLSRV_SCROLL_FIRST);
        if ($row !== NULL){
            if (!is_object($row[$column])){
                if (!preg_match('/["'&<>]/', $row[$column])){
                    if (($this->type === "Image") or ($this->type === "Var Binary")){
                        $this->retVal["nonEmpty"] = true;
                        $this->retVal["value"] = bin2hex($row[$column]);
                    } else {
                        $this->retVal["nonEmpty"] = true;
                        $this->retVal["value"] = $row[$column]; //These two lines. 
                    }
                } else {
                    $expl = explode(""", $row[$column]);
                    $wrkStrg = implode("&quot;", $expl);
                    $expl = explode("'", $wrkStrg);
                    $wrkStrg = implode("&#39;", $expl);
                    $expl = explode("&", $wrkStrg);
                    $wrkStrg = implode("&amp;", $expl);
                    $expl = explode("<", $wrkStrg);
                    $wrkStrg = implode("&lt;", $expl);
                    $expl = explode(">", $wrkStrg);
                    $wrkStrg = implode("&gt;", $expl);
                    $this->retVal["nonEmpty"] = true;
                    $this->retVal["value"] = $wrkStrg;
                    $expl = array();
                    $wrkStrg = Null;
                }
            } else {
                $this->retVal["nonEmpty"] = true;
                $this->retVal["value"] = $row[$column]->format('Y-m-d H:i:s');
            }
            //Used to be here! :(
        }
    } else {
        echo "<p>Table: " . $table . "<br/>Column: " . $column . "</p>";        
        echo "<p>Falure: Seven</p>";
        die(var_dump(SQLSRV_ERRORS(), true));
    }
}

所以我只需要在那里添加其他内容并移动这两行。我很尴尬，我没有早点看到。

Answer 2

您可以将对象序列化为字符串并将字符串反序列化为对象
阅读此参考资料
http://php.net/manual/en/language.oop5.serialization.php