PHP Unconference Europe 2015

fbsql_num_rows

(PHP 4 >= 4.0.6, PHP 5)

fbsql_num_rowsRestituisce il numero di righe presenti in un set di risultati

Descrizione

int fbsql_num_rows ( resource $result )

fbsql_num_rows() restituisce il numero di righe presenti in un set di risultati. Questo comando vale solo per le SELECT. Per sapere il numero di righe coinvolte da un INSERT, UPDATE o DELETE, utilizzare fbsql_affected_rows().

Example #1 Esempio di uso di fbsql_num_rows()

<?php

$link 
fbsql_connect("localhost""username""password"); 
fbsql_select_db("database"$link);

$result fbsql_query("SELECT * FROM table1;"$link); 
$num_rows fbsql_num_rows($result); 

echo 
"$num_rows Rows\n";

?>

Vedere anche: fbsql_affected_rows(), fbsql_connect(), fbsql_select_db() e fbsql_query().

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User Contributed Notes 1 note

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daggillies at yahoo dot com
12 years ago
Note that this function will not always return the actual size of a result set. For example, if you are doing a two-table join along the lines of "SELECT * FROM T1,T2 where T1.x=T2.x" you will get a result of -1. This is due to the 'lazy execution' model in FrontBase whereby result rows are only returned as you request them. If you absolutely have to have the number of rows in advance then you will have to use COUNT(*) first. Most of the time you do not need to know the exact number of rows; it is good enough to know if the size of the result set is non-zero.

David Gillies
San Jose
Costa Rica
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