我想保存DB（phpmyadmin）Mathjax html - ＆gt; tex代码

Question

我制作了mathjax编辑器，并成功完成了Mathjax转换。

但我试过保存DB文本.....例如，我的截图

我想在DB中保存此文本。

所以javascript var txt = ~~ .innerHTML但是..

<span class="MathJax_Preview"></span>
this is&nbsp;
<span class="MathJax" id="MathJax-Element-1-Frame" tabindex="-1">
    <nobr>
        <span class="math" id="MathJax-Span-1" role="math" style="width: 1.158em; display: inline-block;">
            <span style="display: inline-block; position: relative; width: 0.948em; height: 0px; font-size: 119%;">
                <span style="position: absolute; clip: rect(0.003em 1000.95em 1.158em -999.997em); top: -0.995em; left: 0.003em;">
                    <span class="mrow" id="MathJax-Span-2">
                        <span class="msubsup" id="MathJax-Span-3">
                            <span style="display: inline-block; position: relative; width: 0.948em; height: 0px;">
                                <span style="position: absolute; clip: rect(3.416em 1000.53em 4.152em -999.997em); top: -3.989em; left: 0.003em;">
                                    <span class="mi" id="MathJax-Span-4" style="font-family: MathJax_Math-italic;">a</span>
                                    <span style="display: inline-block; width: 0px; height: 3.994em;"></span>
                                </span>
                                <span style="position: absolute; top: -4.357em; left: 0.528em;">
                                    <span class="mn" id="MathJax-Span-5" style="font-size: 70.7%; font-family: MathJax_Main;">2</span>
                                    <span style="display: inline-block; width: 0px; height: 3.994em;"></span>
                                </span>
                            </span>
                        </span>
                    </span>
                    <span style="display: inline-block; width: 0px; height: 1.001em;"></span>
                </span>
            </span>
            <span style="display: inline-block; overflow: hidden; vertical-align: -0.059em; border-left: 0px solid; width: 0px; height: 1.128em;"></span>                
        </span>
    </nobr>
</span>
&nbsp;

<script type="math/tex" id="MathJax-Element-1">
    a^2
</script>

不是一个非常漂亮的DB文本。

我想要DB文本 - ＆gt;这是$ a ^ 2 $（Mathjax texcode）