PHP PDOStatement:: bindColumn Explanation

PDOStatement::bindColumn

PDOStatement:: bindColumn--Bind 1 column to 1 PHP variable (PHP 5 > = 5.1.0, PECL pdo > = 0.1.0)

Description

Grammar

bool PDOStatement::bindColumn ( mixed $column , mixed &$param [, int $type [, int $maxlen [, mixed $driverdata ]]] )

Arranges a specific variable to bind to a given column in a query result set. Each call PDOStatement::fetch() Or PDOStatement::fetchAll() All variables bound to columns are updated.

Note: PDO column information is not always available before the statement is executed, and portable applications should be in PDOStatement::execute() This function (method) is then called.

However, in order to bind an LOB column as a stream when using the PgSQL driver, the application must call the PDOStatement::execute() This method is called before, otherwise the large object OID is returned as an integer.

Parameter

column

Column number (indexed from 1) or column name in the result set. If you use column names, note that the name should keep 1 case with the column name returned by the driver.

param

The name of the PHP variable that will be bound to the column

type

The data type of the parameter specified by the PDO:: PARAM_* constant.

maxlen

Pre-allocation prompt.

driverdata

Optional parameters of the drive.

Return value

Returns TRUE on success or FALSE on failure.

Instances

Bind the result set output to an PHP variable

Binding the columns in the result set to an PHP variable is an effective way to make the data contained in each row immediately available in your application. The following example demonstrates how PDO binds and retrieves columns with multiple options and defaults.

<?php
function readData($dbh) {
 $sql = 'SELECT name, colour, calories FROM fruit';
 try {
  $stmt = $dbh->prepare($sql);
  $stmt->execute();
  /*  Bind by column number  */
  $stmt->bindColumn(1, $name);
  $stmt->bindColumn(2, $colour);
  /*  Bind by column name  */
  $stmt->bindColumn('calories', $cals);
  while ($row = $stmt->fetch(PDO::FETCH_BOUND)) {
   $data = $name . "\t" . $colour . "\t" . $cals . "\n";
   print $data;
  }
 }
 catch (PDOException $e) {
  print $e->getMessage();
 }
}
readData($dbh);
?>

The above routine outputs:

apple red 150
banana yellow 175
kiwi green 75
orange orange 150
mango red 200
strawberry red 25

Summarize