When you use query method, You'll get count right away
<?php
$dbh = new PDO('odbc:sample', 'db2inst1', 'ibmdb2');
$sth = $dbh->query("SELECT name, colour FROM fruit");
$count = $sth->columnCount();
echo 'query count is '.$count;
?>
PDOStatement::columnCount
(PHP 5 >= 5.1.0, PHP 7, PHP 8, PECL pdo >= 0.2.0)
PDOStatement::columnCount — Returns the number of columns in the result set
Descrizione
Use PDOStatement::columnCount() to return the number of columns in the result set represented by the PDOStatement object.
If the PDOStatement object was returned from PDO::query(), the column count is immediately available.
If the PDOStatement object was returned from PDO::prepare(), an accurate column count will not be available until you invoke PDOStatement::execute().
Elenco dei parametri
Questa funzione non contiene parametri.
Valori restituiti
Returns the number of columns in the result set represented by the
PDOStatement object, even if the result set is empty. If there is no result set,
PDOStatement::columnCount() returns 0.
Errori/Eccezioni
Emits an error with level E_WARNING if the attribute PDO::ATTR_ERRMODE is set
to PDO::ERRMODE_WARNING.
Throws a PDOException if the attribute PDO::ATTR_ERRMODE
is set to PDO::ERRMODE_EXCEPTION.
Esempi
Example #1 Counting columns
This example demonstrates how PDOStatement::columnCount() operates with and without a result set.
<?php
$dbh = new PDO('odbc:sample', 'db2inst1', 'ibmdb2');
$sth = $dbh->prepare("SELECT name, colour FROM fruit");
/* Count the number of columns in the (non-existent) result set */
$colcount = $sth->columnCount();
print "Before execute(), result set has $colcount columns (should be 0)\n";
$sth->execute();
/* Count the number of columns in the result set */
$colcount = $sth->columnCount();
print "After execute(), result set has $colcount columns (should be 2)\n";
?>Il precedente esempio visualizzerà:
Before execute(), result set has 0 columns (should be 0) After execute(), result set has 2 columns (should be 2)
Vedere anche:
- PDO::prepare() - Prepares a statement for execution and returns a statement object
- PDOStatement::execute() - Executes a prepared statement
- PDOStatement::rowCount() - Returns the number of rows affected by the last SQL statement
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User Contributed Notes 1 note
756567406 at qq dot com ¶
8 years ago
