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PDOStatement->columnCount
(PHP 5 >= 5.1.0, PECL pdo >= 0.2.0)
PDOStatement->columnCount — Returns the number of columns in the result set
Beschreibung
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().
Rückgabewerte
Returns the number of columns in the result set represented by the PDOStatement object. If there is no result set, PDOStatement::columnCount() returns 0.
Beispiele
Beispiel #1 Counting columns
This example demonstrates how PDOStatement::columnCount() operates with and without a result set.
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$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");
Das oben gezeigte Beispiel erzeugt folgende Ausgabe:
Before execute(), result set has 0 columns (should be 0) After execute(), result set has 2 columns (should be 2)
Siehe auch
- 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