autoPrepare & autoExecute
Описание
Purpose
autoPrepare() and autoExecute() reduce the need to write boring INSERT, UPDATE, DELETE or SELECT SQL queries which are difficult to maintain when you add a field for instance. It requires the use of the Extended module
Imagine you have a 'user' table with 3 fields (id, name and country). You have to write sql queries like:
INSERT INTO table (id, name, country) VALUES (?, ?, ?) UPDATE table SET id=?, name=?, country=? WHERE ...
If you add a field ('birthYear' for example), you have to rewrite your queries which is boring and can lead to bugs (if you forget one query for instance).
autoPrepare
With autoPrepare(), you don't have to write your insert, update, delete or select queries. For example:
<?php
// Once you have a valid MDB2 object named $mdb2...
$table_name = 'user';
$table_fields = array('id', 'name', 'country');
$types = array('integer', 'text', 'text');
$mdb2->loadModule('Extended');
$sth = $mdb2->extended->autoPrepare($table_name, $table_fields,
MDB2_AUTOQUERY_INSERT, null, $types);
if (PEAR::isError($sth)) {
die($sth->getMessage());
}
?>
In this example, autoPrepare() will build the following SQL query:
INSERT INTO user (id, name, country) VALUES (?, ?, ?)
And then, it will call prepare() with it.
To add records, you have to use execute() or executeMultiple() like:
<?php
// ... continuing from the example above...
$table_values = array(1, 'Fabien', 'France');
$res =& $sth->execute($table_values);
if (PEAR::isError($res)) {
die($res->getMessage());
}
?>
So, you don't have to write any SQL INSERT queries! And it works with UPDATE and DELETE queries too. For flexibility reasons, you have only to write the WHERE clause of the query. For instance:
<?php
// Once you have a valid MDB2 object named $mdb2...
$table_name = 'user';
$mdb2->loadModule('Extended');
$sth = $mdb2->extended->autoPrepare($table_name, null,
MDB2_AUTOQUERY_DELETE, 'id = '.$mdb2->quote(1, 'integer'));
if (PEAR::isError($sth)) {
die($sth->getMessage());
}
$res =& $sth->execute($table_values);
if (PEAR::isError($res)) {
die($res->getMessage());
}
?>
autoPrepare() will build the following query:
UPDATE user SET name=?, country=? WHERE id=1
Then, it will call prepare() with it.
Be careful, if you don't specify any WHERE clause, all the records of the table will be updated.
autoExecute
Using autoExecute() is the easiest way to do insert, update, delete or select queries. It is a mix of autoPrepare() and execute().
You only need an associative array (key => value) where keys are fields names and values are corresponding values of these fields. This is only relevant for insert and update queries. For instance:
<?php
// Once you have a valid MDB2 object named $mdb2...
$table_name = 'user';
$fields_values = array(
'id' => 1,
'name' => 'Fabien',
'country' => 'France'
);
$types = array('integer', 'text', 'text');
$mdb2->loadModule('Extended');
$affectedRows = $mdb2->extended->autoExecute($table_name, $fields_values,
MDB2_AUTOQUERY_INSERT, null, $types);
if (PEAR::isError($affectedRows)) {
die($affectedRows->getMessage());
}
?>
And that's all! The following query is built and executed:
INSERT INTO user (id, name, country) VALUES (1, 'Fabien', 'France')
And it's the same thing for UPDATE queries:
<?php
// Once you have a valid MDB2 object named $mdb2...
$table_name = 'user';
$fields_values = array(
'name' => 'Fabien',
'country' => 'France'
);
$types = array('text', 'text');
$mdb2->loadModule('Extended');
$affectedRows = $mdb2->extended->autoExecute($table_name, $fields_values,
MDB2_AUTOQUERY_UPDATE, 'id = '.$mdb2->quote(1, 'integer'), $types);
if (PEAR::isError($affectedRows)) {
die($affectedRows->getMessage());
}
?>
which prepares and executes the following query:
UPDATE user SET name='Fabien', country='France' WHERE id = 1
Be careful, if you don't specify any WHERE statement, all the records of the table will be updated.
Here is an example for a DELETE queries:
<?php
// Once you have a valid MDB2 object named $mdb2...
$table_name = 'user';
$mdb2->loadModule('Extended');
$affectedRows = $mdb2->extended->autoExecute($table_name, null,
MDB2_AUTOQUERY_DELETE, 'id = '.$mdb2->quote(1, 'integer'));
if (PEAR::isError($affectedRows)) {
die($affectedRows->getMessage());
}
?>
which prepares and executes the following query:
DELETE FROM user WHERE id = 1
Finally an example for a SELECT queries:
<?php
// Once you have a valid MDB2 object named $mdb2...
$table_name = 'user';
// if left as a non array all fields of the table will be fetched using '*'
// in that case this variable can be set to true, to autodiscover the types
$result_types = array(
'name' => 'text',
'country' => 'text'
);
$mdb2->loadModule('Extended');
$res = $mdb2->extended->autoExecute($table_name, null,
MDB2_AUTOQUERY_SELECT, 'id = '.$mdb2->quote(1, 'integer'),
null, true, $result_types);
if (PEAR::isError($res)) {
die($res->getMessage());
}
$row = $res->fetchRow();
?>
which prepares and executes the following query:
SELECT name, country FROM user WHERE id = 1
You can also use placeholders in the WHERE clause and pass the values like this:
<?php
$id = 1;
$mdb2->autoExecute('table_name', array($id), MDB2_AUTOQUERY_DELETE, 'id = ?');
?>
which prepares the following query and passes the $id parameter on execute:
DELETE FROM table_name WHERE id = ?
The values passed in
$datamust be literals. Do not submit SQL functions (for exampleCURDATE()). SQL functions that should be performed at execution time need to be put in the prepared statement.