在mysql_query中使用if语句？

Question

I have a news table and I want to echo out a different statement depending on what type of news it is. The type is stored in the field named "type" in the table.

Here's the basic code I'm using to return the data to an array

$query = mysql_query("SELECT * FROM news");
while ($row = mysql_fetch_assoc($result)) {
} 

So at the moment I'm returning all the information from the table 'news' but I want to echo out different statements depending on the type within the row.

The purpose of the table is to display user submitted news with different pre-defined text based on the type field.

To give an example of what I mean: if the row contains the type "release_date" echo out ''name' will be released on". If the row contains the type of new_video echo "'name' has a new video". It also then needs to be ordered by the submission date which is also contained in the table.

I don't want to do this with seperate queries because I need to arrange all of the news by submission date. Would the best way of doing this be with an if statement? I'm a bit lost for ideas at the moment, any advice will be really appreciated. Hope this makes sense

Answer 1

To order the results by date you could extend your query like this

SELECT * FROM news ORDER BY `submission_date` DESC //or "ASC" for opposite order

by using your column name. To handle different results

while ($row = mysql_fetch_assoc($result)) { //for each returned row
  switch($row['type']){ //your column name for field
    case 'release_date':
      echo $row['name']." will be released on";
      break;
    case 'new_video':
      echo $row['name']." has a new video";
      break;
      //other cases
    default: //if there should be a process for "anything else"-cases
      //code
      break;
   }
}

edit:

"echo" at this point won't make you happy; I guess you want to output the results in html; then you have to define a variable before the loop starts and fill it inside the loop. Like this:

$html = ''; //set variable
while ($row = mysql_fetch_assoc($result)) { //for each returned row
  switch($row['type']){ //your column name for field
    case 'release_date':
      $html .= "<p>".$row['name']." will be released on</p>";
      break;
    case 'new_video':
      $html .= "<p>".$row['name']." has a new video</p>";
      break;
      //other cases
    default: //if there should be a process for "anything else"-cases
      //code
      break;
   }
}
echo $html; 
/*$html is now filled with some paragraphs.
You should echo it inside a complete html-structure 
with doctype and inside the body-tag.
The position of the echo inside you script depends on the rest of your code. */

Because you're inserting userdefined content make sure that the inputs are

1. escaped
2. trimmed or the switch-case may not work

And please notice eggyal's comment, I've just taken your code. Do not use mysql_query.

Answer 2

You could do this in your PHP code. If you want to do this in the SQL query, then you can use CASE for this:

SELECT CONCAT('\'', name, '\' ',
              CASE type
              WHEN 'release_date' THEN 'will be released on'
              WHEN 'new_video' THEN 'has a new video'
              ELSE 'did something unexpected'
              END)
FROM news
ORDER BY submission_date DESC

Note that the use of CONCAT is just an example. You could still combine the text fragments in PHP. Or you could have a CASE on the outside, and different CONCAT expressions in each of the THEN clauses. Depends on what exactly you need, whether you always want a quoted name up front for example.