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    <p>It depends on what you mean.</p> <p><a href="http://ca2.php.net/mysql_result" rel="nofollow noreferrer">mysql_result</a> returns <code>FALSE</code> on failure, which would happen if you specified an invalid (row,field). To check for this you'd want to do use the identicality operator <code>===</code>, which checks both value and type. The equality operator <code>==</code>, the <code>empty()</code> function, and the conditional evaluation of an if statement all check the value but not the type.</p> <p>This means that using one of those methods there's no difference between various values that all equate to <code>Boolean FALSE</code>, like empty strings, empty arrays, the string <code>'0'</code>, and the value <code>NULL</code>.</p> <p>So if you want to be really thorough about it you could do something like the following:</p> <pre><code>if ($description === FALSE) { throw new Exception("The row $i was out of range in query $query."); } else if ($description === NULL) { // assuming that the description field has a default value of NULL // * this one I'm not sure about.. the documentation for mysql_result claims // that it returns a string, so this may never happen. // It's left as an exercise for the reader. throw new Exception("Uninitialized value in result row $i of db query $query"); } else if ($description === '') { echo "No description available"; } else { echo $description; } </code></pre> <p>Since <code>empty()</code> returns <code>true</code> under a similar set of conditions to an equality (<code>==</code>) with <code>FALSE</code>, this more strict in your type checking would be especially important in cases where the result might actually be <code>"0"</code>. </p> <p>Apparently I'm not allowed to post more than one hyperlink, so I wasn't able to link to the documentation for comparison operators ("<a href="http://php.net/manual/en/language.operators.comparison.php" rel="nofollow noreferrer">http://php.net/manual/en/language.operators.comparison.php</a>") or the empty function ("<a href="http://php.net/empty" rel="nofollow noreferrer">http://php.net/empty</a>"). Fortunately their security is relatively lax. Mwuh Hah!</p>
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    1. USChristian Giupponi
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Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

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