查询只返回一行（PHP / MYSQL）
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【中文标题】查询只返回一行（PHP / MYSQL）【英文标题】：Query only returning one row (PHP / MYSQL) 【发布时间】：2020-06-26 22:05:17 【问题描述】：尝试在 javascript 中使用 php 返回一些行时遇到问题...
当我将结果作为纯文本回显时，它可以正常工作。但是当我尝试用结果填充地图时，它只显示数据库中的一行/标记，而不是表格的其余部分
screenshot shows only one marker returning on map instead of all results from the database
这是页面的完整代码..
<?php include("header.php");
// Connect to the hydrants table and set ORDER BY to ASC or DESC
$sql = "SELECT id, lat, lng, flow, pressure, type, lid, updated FROM hydrants_OLD ORDER BY id ASC";
$result = $conn->query($sql);
// Display the results of the query
while($row = $result->fetch_assoc()) ;
?>
<head>
<title>Hydrants</title>
<meta name="viewport" content="initial-scale=1.0">
<link rel="Shortcut Icon" href=images/hl.png>
<meta name="mobile-web-app-capable" content="yes">
<link rel="icon" href="images/hl.png">
<!--<meta name="apple-mobile-web-app-capable" content="yes">-->
<meta name="apple-mobile-web-app-status-bar-style" content="black-translucent">
<meta name="apple-mobile-web-app-title" content="Hydrants">
<link rel="apple-touch-icon" href="images/h-apple.png"><link rel="apple-touch-startup-image" media="(device-width: 320px) and (device-height: 568px) and (-webkit-device-pixel-ratio: 2)" href="images/h-apple.png"><link rel="apple-touch-startup-image" media="(device-width: 768px) and (orientation: portrait)" href="images/h-apple.png">
<meta charset="utf-8">
<style>
/* Always set the map height explicitly to define the size of the div
* element that contains the map. */
#map
height: 100%;
/* Optional: Makes the sample page fill the window. */
html, body
height: 100%;
margin: 0;
padding: 0;
</style>
</head>
<body bgcolor="#ffffff">
<?php
$lat = $row['lat'];
$lng = $row['lng'];
$id = $row['id'];
$flow = $row['flow'];
$pressure = $row['pressure'];
$type = $row['type'];
$lid = $row['lid'];
$updated = $row['updated'];
?>
<?php echo $id, $lat, $lng, $flow, $pressure, $type, $lid, $updated, "<br>" ; ?>
<div id="map"></div>
<script>
var map, infoWindow;
function initMap()
// Map options
var options =
// zoom:17,
zoom:14,
center: lat: 53.428345, lng: -6.244447,
var map = new google.maps.Map(document.getElementById('map'), options);
// Array of markers
var markers = [
// HYDRANTS
coords:lat:<?php echo $lat ?>,lng:<?php echo $lng ?>, iconImage:'images/hs.png', content:'<h2>Hydrant - Number <?php echo $id ?></h2><b>Flow</b> <?php echo $flow ?> Liters per minute<br><b>Pressure</b> <?php echo $pressure ?> bar<br><br><?php echo $type ?><br><?php echo $lid ?><br><br><center><a href=images/hydrants/<?php echo $id ?>.jpg><img src=images/hydrants/<?php echo $id ?>.jpg width=100%></a>Updated <?php echo $updated ?><br><br><a href="report.php?id=<?php echo $id ?>">Report problem with this hydrant</a></center>'
];
// Loop through markers
for(var i = 0;i < markers.length;i++)
// Add marker
addMarker(markers[i]);
// Add Marker Function
function addMarker(props)
var marker = new google.maps.Marker(
position:props.coords,
map:map,
//icon:props.iconImage
);
// Check for customicon
if(props.iconImage)
// Set icon image
marker.setIcon(props.iconImage);
// Check content
if(props.content)
var infoWindow = new google.maps.InfoWindow(
content:props.content
);
marker.addListener('click', function()
infoWindow.open(map, marker);
);
infoWindow = new google.maps.InfoWindow;
</script>
<script async defer
src="https://maps.googleapis.com/maps/api/js?key=0000MYAPIKEY0000&callback=initMap">
</script>
</body>
<?php
// Close database connection
$conn->close();
?>
【问题讨论】：
您正在为数据库中的每个条目创建完整的 html，这意味着您有 n 个head 标签，n 个 body 标签...修复您的代码以提取循环外的通用结构以创建有效的 html。此外，您的问题的标题不准确 - 如果 php 回显多个结果，那么您的查询不是问题。
【参考方案1】：
问题是循环部分中有 html 代码，这意味着您正在为每个坐标创建地图。考虑到您的代码，我认为最好的方法是创建一个标记数组，然后使用 json_encode 方法将其转换为 JSON，并将其打印到您的 javascript 代码上的变量中。
// Display the results of the query
$markers = [];
while($row = $result->fetch_assoc())
$markers[] = [
'coords' => [
'lat' => $row['lat'],
'lng' => $row['lng']
],
'iconImage' => 'images/hs.png',
'content' => "<h2>Hydrant - Number $row['id']</h2><b>Flow</b> $row['flow'] Liters per minute<br><b>Pressure</b> $row['pressure'] bar<br><br>$row['type']<br>$row['lid']<br><br><center><a href=images/hydrants/$row['id'].jpg><img src=images/hydrants/$row['id'].jpg width=100%></a>Updated $row['updated']<br><br><a href=\"report.php?id=$row['id']\">Report problem with this hydrant</a></center>"
];
然后在您的 javascript 上，只需添加一个像这样的变量并打印编码结果：
var markers = <?php echo json_encode($markers); ?>;
整个代码：
<?php include("header.php");
// Connect to the hydrants table and set ORDER BY to ASC or DESC
$sql = "SELECT id, lat, lng, flow, pressure, type, lid, updated FROM hydrants_OLD ORDER BY id ASC";
$result = $conn->query($sql);
// Display the results of the query
$markers = [];
while($row = $result->fetch_assoc())
$markers[] = [
'coords' => [
'lat' => $row['lat'],
'lng' => $row['lng']
],
'iconImage' => 'images/hs.png',
'content' => "<h2>Hydrant - Number $row['id']</h2><b>Flow</b> $row['flow'] Liters per minute<br><b>Pressure</b> $row['pressure'] bar<br><br>$row['type']<br>$row['lid']<br><br><center><a href=images/hydrants/$row['id'].jpg><img src=images/hydrants/$row['id'].jpg width=100%></a>Updated $row['updated']<br><br><a href=\"report.php?id=$row['id']\">Report problem with this hydrant</a></center>"
];
// echo "$row['id'], $row['lat'], $row['lng'], $row['flow'], $row['pressure'], $row['type'], $row['lid'], $row['updated'], <br>" ;
?>
<head>
<title>Hydrants</title>
<meta name="viewport" content="initial-scale=1.0">
<link rel="Shortcut Icon" href=images/hl.png>
<meta name="mobile-web-app-capable" content="yes">
<link rel="icon" href="images/hl.png">
<!--<meta name="apple-mobile-web-app-capable" content="yes">-->
<meta name="apple-mobile-web-app-status-bar-style" content="black-translucent">
<meta name="apple-mobile-web-app-title" content="Hydrants">
<link rel="apple-touch-icon" href="images/h-apple.png"><link rel="apple-touch-startup-image" media="(device-width: 320px) and (device-height: 568px) and (-webkit-device-pixel-ratio: 2)" href="images/h-apple.png"><link rel="apple-touch-startup-image" media="(device-width: 768px) and (orientation: portrait)" href="images/h-apple.png">
<meta charset="utf-8">
<style>
/* Always set the map height explicitly to define the size of the div
* element that contains the map. */
#map
height: 100%;
/* Optional: Makes the sample page fill the window. */
html, body
height: 100%;
margin: 0;
padding: 0;
</style>
</head>
<body bgcolor="#ffffff">
<div id="map"></div>
<script>
var map, infoWindow;
function initMap()
// Map options
var options =
// zoom:17,
zoom:14,
center: lat: 53.428345, lng: -6.244447,
var markers = <?php echo json_encode($markers); ?>;
var map = new google.maps.Map(document.getElementById('map'), options);
// Loop through markers
for(var i = 0;i < markers.length;i++)
// Add marker
addMarker(markers[i]);
// Add Marker Function
function addMarker(props)
var marker = new google.maps.Marker(
position:props.coords,
map:map,
//icon:props.iconImage
);
// Check for customicon
if(props.iconImage)
// Set icon image
marker.setIcon(props.iconImage);
// Check content
if(props.content)
var infoWindow = new google.maps.InfoWindow(
content:props.content
);
marker.addListener('click', function()
infoWindow.open(map, marker);
);
infoWindow = new google.maps.InfoWindow;
</script>
<script async defer
src="https://maps.googleapis.com/maps/api/js?key=0000MYAPIKEY0000&callback=initMap">
</script>
</body>
<?php
// Close database connection
$conn->close();
?>
【讨论】：
感谢您的回复，我根本不是专家，感谢您的帮助。我现在收到以下错误，但是在第 18 行“解析错误：语法错误，意外'报告'（ T_STRING)，在第 18 行的 index.php 中期待 ']'" 不幸的是，现在我收到“此页面未正确加载 Google 地图。有关技术详情，请参阅 JavaScript 控制台。”并且在控制台中有“InvalidValueError: setPosition: not a LatLng or LatLngLiteral: in property lat: not a number”“1.jpg:1 GET images/hydrants/1.jpg 404 (Not Found)”。 “2.jpg:1 GET images/hydrants/2.jpg 404（未找到）”“js?key=AIzaSyBlvLFqjIwxRtvdJanpfUAai5883G9t6&callback=initMap:55 Google Maps JavaScript API 错误：InvalidKeyMapError” 在markers 变量后面添加以下代码：标记[i].coords.lng = parseFloat(标记[i].coords.lng);
我会尽快尝试，因为我不得不去，我现在正在通过电话回复...感谢到目前为止的帮助
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