如果/其他有条件 <select>选项

Question

I am having troubling getting a simply if/else conditional for options in an html select form. If the value for bid is 'N', then I want one option for the select field to change to "Y" and vice versa. I know my db connection is good and other php works and the form was updating the db fine until I tried to work in the php conditional code within the so I just need to get the syntax correct.

 /* fetch associative array */
 while ($row = mysqli_fetch_assoc($result)){
 ?>

 <form method="post" name="update" action="update.php" >
 <select name="bid">

 <option value="<?php echo $row['bid']; ?>" selected="selected">
 <?php echo $row['bid']; ?></option>

 <? if ($row['bid'] == 'N') {  
 ?>

 <option value="Y">Y</option>

 <?   } else {

 ?>

 <option value="N">N</option>

 <? }
 ?>

</select>
<input type="submit" name="Submit" value="update" > 
</form>

<?
}

Answer 1

if statement expect expression and you have syntax error in your statement

if (echo $row['bid']; == 'N')

the syntax error because of echo and the semicolon ;

you should change your condition to

if ($row['bid'] == 'N'){

if $row['bid'] string then you need to compare with strcmp , like this

if (strcmp($row['bid'] , 'N') == 0){

also you need to move <input> tag outside the <select>

Answer 2

Your <input type="submit"> was inside your <select> , so I moved it outside.

It is also incorrect to use the if statement in this manner:

if (echo $row['bid']; == 'N')

correct would be this:

if ($row['bid'] == 'N')

Here is the corrected code:

<form method="post" name="update" action="update.php" >
<select name="bid">

<?php
echo '<option value="'.$row['bid'].'" selected="selected">'.$row['bid'].'</option>';

if ($row['bid'] == 'N') echo '<option value="Y">Y</option>';
else echo '<option value="N">N</option>';

echo '</select>';
?>

<input type="submit" name="Submit" value="update" >
</form>

Answer 3

Your condition is bad, you must remove echo and ; . it should like this

<? if ($row['bid'] == 'N') { ?>

And your submit button should be presented out side the select field. Your codes should look like this:

<form method="post" name="update" action="update.php" >
    <select name="bid">

       <option value="<?=$row['bid']?>" selected="selected">
           <?=$row['bid']?>
       </option>

      <?php if ($row['bid'] == 'N') { 
          echo '<option value="Y">Y</option>';
      } else {
          echo '<option value="N">N</option>';
      }
      ?>

     </select>
     <input type="submit" name="Submit" value="update" > 
 </form>

Answer 4

Your if condition has bad syntax. Remove the semicolon and echo statement.

<form method="post" name="update" action="update.php" >
 <select name="bid">

 <option value="<?php echo $row['bid']; ?>" selected="selected">
 <?php echo $row['bid']; ?></option>

 <? if ($row['bid'] == 'N') {  
 ?>

 <option value="Y">Y</option>

 <?   } else {

 ?>

 <option value="N">N</option>

 <? }
 ?>

 <input type="submit" name="Submit" value="update" >

 </select> 
 </form>