如何根据第三列从两列中选择值 [英] how to select value from two columns based on third column

问题描述

我有一个以书籍命名的数据库表。它由以下内容组成

 -------------------- ------------------------------------------- 
 title |作者| category 
 | | 
 ---------------------------------------------- ---------------- 
 
 xyz狂人小说
 
适应无脑小说
 
 adaxx愚蠢小说
 
关注白痴期刊
 
你的男人acadamic 
 ------------------------- ------------------------------------- 

用户试图按作者或标题搜索价值并基于类别

例如：如果用户通过选择小说来搜索适应需要显示适应和adaxx <下面的
是使用mysql数据库的代码

 <  表格    action   =  search.php   方法  = 发布 >  
 <？ php 
 $ select_query =  从书籍中选择不同的类别; 
  $ select_query_run  = mysql_query（$ select_query）; 
 $ select_query_array = mysql_fetch_array（$ select_query_run）; 
  $ cat  = $ select_query_array ['  category ]; 
  echo   < select name ='名'>中; 
  while （$ select_query_array = mysql_fetch_array（$ select_query_run））
 { //  动态下拉列表 
 
  echo    < option value =' .htmlspecialchars（$ select_query_array [  category]）。 '>。 htmlspecialchars（$ select_query_array [  category]）。  < / option>; 
} 
 
  echo   < /选择> 中; 
 ？>  
 <  输入   类型  =  text    name   =  searchvalue    size   =  5      id   =  searchfield    title   =  searchfield    onFocus   =  clearText（this）  /  >  
 <  < span class =code-leadattribute> input     type   = 提交   名称  = 提交    value   =     alt   = 搜索    id   =  searchbutton    title   = 搜索    /  >  
 <  < span class =code-leadattribute> / form  >  
 <？ php 
  $ button  = $ _POST [' 提交']; 
  $ search  = $ _POST ['  searchvalue ]; 
 if（strlen（$ search）< = 1）
 {
  $ name  = $ _POST ['  name']; 
  //   echo $ a;  
  echo   搜索词太短; 
} 
 else {
  echo   您搜索了 $ search < hr size ='1'>< / br>; 
  $ search_exploded  = explode（ ，$ search）; 
  $ x  =  ; 
  $ construct  =  ; 
 foreach（$ search_exploded  as  $ search_each）
 {
 $ x ++; 
 if（$ x == 1）
  $ construct 。=  < span class =code-string> title LIKE'％$ search_each％'; 
  else  
  $ construct 。=   AND LIKE'％$ search_each％'; 
 
} 
  $ construct  =   SELECT * FROM books WHERE $ construct and category ='$ name';  //  我试过这个但没有工作 
 
  $ run  = mysql_query（$ construct）; 
  $ foundnum  = mysql_num_rows（$ run）; 
  if （$ foundnum == 0）
  echo   抱歉， $ search 没有匹配的结果。< / br>< / br> 1。 ; 
  else  
 {
  echo    $ foundnum results found！< p>; 
} 
 ？>  

解决方案

select_query = 从书籍中选择不同的类别;

select_query_run = mysql_query（

select_query）;

I have a database table named with books. it consists of something like below

---------------------------------------------------------------
     title         |     author           |    category
                   |                      |  
--------------------------------------------------------------

    xyz                   madman                  fiction

    adapt                 brainless               fiction
     
    adaxx                   stupid                fiction

    follow                 idiot                  journal

    your                    man                   acadamic
--------------------------------------------------------------

user is trying to search the value by author or title and based on category
ex: if user search for adapt by selecting fiction need display both adapt and adaxx
below is the code
using mysql database

<form action="search.php" method="post">
<?php
$select_query=          "Select distinct category from books";
$select_query_run =     mysql_query($select_query);
$select_query_array=   mysql_fetch_array($select_query_run) ;
 $cat = $select_query_array['category'];
echo "<select name='name'>";
while ($select_query_array=   mysql_fetch_array($select_query_run) )
{// dynamic drop list

  echo "<option value='".htmlspecialchars($select_query_array["category"])."' >".htmlspecialchars($select_query_array["category"])."</option>";
}

echo "</select>";
?>
   <input type="text" name="searchvalue" size="5"  id="searchfield" title="searchfield" onFocus="clearText(this)"/>
     <input type="submit" name="submit" value="" alt="Search" id="searchbutton" title="Search" />
</form>
<?php
$button = $_POST['submit'];
$search = $_POST['searchvalue']; 
if(strlen($search)<=1)
{
$name = $_POST['name'];
//echo $a;
echo "Search term too short";
}
else{
echo "You searched for $search <hr size='1'></br>";
$search_exploded = explode (" ", $search);
$x = "";
$construct = "";  
foreach($search_exploded as $search_each)
{
$x++;
if($x==1)
$construct .="title LIKE '%$search_each%'";
else
$construct .="AND title LIKE '%$search_each%'";
 
}
$construct ="SELECT * FROM books WHERE $construct and category = '$name'";// I tried this but not working

$run = mysql_query($construct);
$foundnum = mysql_num_rows($run);
if ($foundnum==0)
echo "Sorry, there are no matching result for $search.</br></br>1.";
else
{
echo "$foundnum results found !<p>";
}
?>

解决方案

select_query= "Select distinct category from books";

select_query_run = mysql_query(

select_query);

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