[英]Column name from sql query in php
I am trying to extract a column name from SQL database to use in a dropdown in HTML. 我试图从SQL数据库中提取列名,以用于HTML的下拉列表中。 I am then trying to insert PHP into the HTML dropdown to display column name.
然后,我尝试将PHP插入HTML下拉列表中以显示列名称。
I have used fetch array to get output from SQL using a variable from another drop down to pull the relevant SQL table. 我已经使用fetch数组使用另一个下拉列表中的变量提取SQL来从SQL获取输出。 However i can't return the column name in PHP.
但是我不能在PHP中返回列名。 All I get is the value using
$row[2].
我所得到的只是使用
$row[2].
的值$row[2].
Is there an easy way to pull the column name (ie the non-numeric value in square brackets after the numerical value). 是否有一种简单的方法来提取列名(即,数值后方括号中的非数字值)。
$query="SELECT * FROM ".($units_cat)."";
if ($result = mysqli_query($link, $query)) {
$row = mysqli_fetch_array($result);
echo nl2br (" \n Query was successful \n");
print_r($row);
echo "<br>";
}
HTML 的HTML
<option value="<?php $row[2]?>"
<?php
if($_POST['units_from']==$row)
echo 'selected="selected"';?>
>
<?php echo ($row[2])?>
</option>
OUTPUT FROM SQL QUERY 从SQL查询输出
Array (
[0] => 1
[id] => 1
[1] => Klbs
[from_value] => Klbs
[2] => 1.0000000000
[klbs] => 1.0000000000
[3] => 1000.0000000000
[pound] => 1000.0000000000
[4] => 0.4535923700
[ton] => 0.4535923700
[5] => 453.5923700000
[kg] => 453.5923700000
[6] => 224.8089424432
[newton] => 224.8089424432
[7] => 22.4808942443
[dn] => 22.4808942443
[8] => 0.2248089424
[kn] => 0.2248089424
)
I was able to do this by using DESCRIBE to output array of table data. 通过使用DESCRIBE输出表数据数组,我能够做到这一点。 Then create an array of the columns.
然后创建一个列数组。
$query2=("DESCRIBE ".mysqli_real_escape_string($link, $units_cat));
if ($result2 = mysqli_query($link, $query2)) {
$table_desc = mysqli_fetch_all($result2);
#Create an array of column values
foreach($table_desc as $val) {
$col[]=$val[0];
}
Then call the column values in the relevant dropdown. 然后在相关的下拉列表中调用列值。
<option value="<?php echo($col[2]) ?>"<?php if($_POST['units_from']==($col[2])) echo
'selected="selected"';?>><?php echo($col[2]) ?></option>
I had to white-list the tables that $units_cat was referencing as I believe you cannot prepare a table as you are unable to bind parameters to a table entry in PHP/SQL. 我不得不将$ units_cat所引用的表列入白名单,因为我相信您无法准备表,因为您无法将参数绑定到PHP / SQL中的表项。
#Get tables list for whitelisting
$query3="Show tables";
$result3=mysqli_query($link,$query3);
if (!$result3) {
echo "DB Error, could not list tables\n";
echo 'MySQL Error: ' . mysqli_error();
exit;
}
if ($result3=mysqli_query($link,$query3)){
while($row=mysqli_fetch_row($result3)){
$tables[]=$row[0];
}
}
#UNITS CAT WHITELIST CHECK
if (in_array($units_cat,$tables)){
echo nl2br (" \n Units Cat Table exists");
}else{
echo "Table does not exist";
mysqli_close($link);
echo "<br>";
die("non valid entry");
}
with mysql_fetch_array you can access each parameter individually $row['id']; 使用mysql_fetch_array,您可以单独访问每个参数$ row ['id']; $row['pound'];
$ row ['pound'];
However, storing the different values for a same variable (in kg, in tons , in...) in the database seems a bit unnecessary taking into account that you can save the space with a simple conversion using the metric unit. 但是,考虑到可以通过使用公制单位进行简单转换来节省空间,在数据库中存储相同变量的不同值(以千克,吨,英寸...为单位)似乎有点不必要。 do your users need to input the weight in different units each time?
您的用户是否需要每次以不同的单位输入重量?
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