对于所有关心的人，if not empty 语句对我有用
我是 SQL 和 PHP 新手，正在尝试实现搜索功能以从处理 Wine 的 MySQL 数据库中获取数据。
我已经弄清楚如何在有一个搜索变量的情况下进行查询，并且我已经弄清楚如何使用两个搜索变量进行查询，我确信我可以继续这种模式 - 但是我是什么想要做的是实现一个搜索功能，可以根据用户输入到变量中的内容进行搜索(这意味着用户必须至少输入一个值，并且搜索将抓取与搜索变量相关的字段)。
假设我有这些搜索变量:
- 酒名 -(用户可以将此留空或输入一个值)
- Wine 类型 -(用户输入值)
- 年份 -(用户可以将此留空或输入一个值)
根据用户输入的变量数量来决定搜索的精确程度。
我尝试搜索论坛，但似乎找不到任何内容。如果我的格式或问题有误，请道歉。希望您能提供任何帮助或指出正确的方向，谢谢!
这是迄今为止我的代码，如果用户输入变量“wineName”和“wineryName”，则该代码有效。尝试使用 isset 触发某种开关，但我认为我没有走在正确的轨道上。
<!DOCTYPE HTML PUBLIC
"-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html401/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<title>Answer Page</title>
</head>
<body bgcolor="white">
<?php
function showerror() {
die("Error " . mysql_errno() . " : " . mysql_error());
}
require 'db.php';
// Show all wines in a region in a <table>
function displayWines($connection, $query, $wineName) {
// Run the query on the server
if (!($result = @ mysql_query ($query, $connection))) {
showerror();
}
// Find out how many rows are available
$rowsFound = @ mysql_num_rows($result);
// If the query has results ...
if ($rowsFound > 0) {
// ... print out a header
print "You searched for $wineName with a region of $wineryName <br><br>";
// and start a <table>.
print "\n<table>\n<tr>" .
"\n\t<th>Wine ID</th>" .
"\n\t<th>Wine Name</th>" .
"\n\t<th>Winery Name</th>" .
"\n\t<th>Year</th>\n</tr>";
// Fetch each of the query rows
while ($row = @ mysql_fetch_array($result)) {
// Print one row of results
print "\n<tr>\n\t<td>{$row["wine_id"]}</td>" .
"\n\t<td>{$row["wine_name"]}</td>" .
"\n\t<td>{$row["winery_name"]}</td>" .
"\n\t<td>{$row["year"]}</td>\n</tr>";
} //end while loop body
//finish table
print "\n</table>";
} //end if $rowsFound body
//Report how many rows were found
print "<br>{$rowsFound} records found matching your criteria<br>";
} //end of function
// Connect to the MySQL server
if (!($connection = @ mysql_connect(DB_HOST, DB_USER, DB_PW))) {
die("Could not connect");
}
//get user data
$wineName = $_GET['wineName'];
$wineryName = $_GET['wineryName'];
if (!mysql_select_db(DB_NAME, $connection)) {
showerror();
}
//start a query
$query = "SELECT wine_id, wine_name, winery_name, year
FROM wine, winery
WHERE wine.winery_id = winery.winery_id";
if (isset($wineName)) {
$query .= " AND wine_name = '{$wineName}'";
}
if (isset($wineryName)) {
$query .= " AND winery_name = '{$wineryName}'";
}
//order the list
$query .= " ORDER BY wine_name";
//run query, show results
displayWines($connection, $query, $wineName);
?>
</body>
</html>
最佳答案
//start a query
$query = "SELECT wine_id, wine_name, winery_name, year
FROM wine, winery
WHERE wine.winery_id = winery.winery_id";
if (isset($wineName)) {
$query .= " AND wine_name LIKE '%$wineName%'";
}
if (isset($wineryName)) {
$query .= " AND winery_name LIKE '%$wineryName%'";
}
//order the list
$query .= " ORDER BY wine_name";
//run query, show results
displayWines($connection, $query, $wineName);
关于PHP 搜索 MySQL 数据库 - 多个搜索变量，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/25285164/