如何使用Jquery $ .post发布复杂的字符串？

Question

我需要帮助将表示多边形的复杂字符串传递给php脚本，其中字符串用于SQL查询。正确的格式是将整个POLYGON语句用单引号括起来。 PHP脚本没有捕获$_POST变量。可能是什么原因？

使用Javascript：

var polyBoundary = "'POLYGON ((-98.13787244260311 30.031055426540206, -95.98455213010311 31.970803930433096, -92.18328259885311 27.89734922968426, -95.69890759885311 26.49024045886963, -98.13787244260311 30.031055426540206))'";

$.post("php/insertPolygon.php", {boundary: polyBoundary}, function (data) {
    alert(data) // this alert never fires
    // Do stuff with the response
}, "json");

PHP：

<?php
    $prjBoundary = $_POST['boundary']; # I'll sanitize once I get everything working
    # Connect to DB, execute SQL query, etc.

    # Make sure I'm sending a response no matter what
    if ( ($errors = sqlsrv_errors() ) !=null) {
        echo "Error!";
    } else {
        echo "SUCCESS!"; # this should have been echo json_encode("SUCCESS!");
    }

PHP错误：Undefined index: boundary in FILENAME on line 2