Query Results
The database class contains many methods for working with a query's result set that you can get after SELECT queries.
Single Value Result
loadResult()
Use loadResult()
when you expect just a single value back from your database query.
id | name | username | |
---|---|---|---|
1 | John Smith | [email protected] | johnsmith |
2 | Magda Hellman | [email protected] | magdah |
3 | Yvonne de Gaulle | [email protected] | ydegaulle |
This is often the result of a 'count' query to get the number of records:
use Joomla\CMS\Factory;
$db = Factory::getContainer()->get('DatabaseDriver');
$query = $db->getQuery(true);
$query->select('COUNT(*)');
$query->from($db->quoteName('#__my_table'));
$query->where($db->quoteName('name')." = :value");
$query->bind('value', $value)
// Reset the query using our newly populated query object.
$db->setQuery($query);
$count = $db->loadResult();
or where you are just looking for a single field from a single row of the table (or possibly a single field from the first row returned).
use Joomla\CMS\Factory;
$db = Factory::getContainer()->get('DatabaseDriver');
$query = $db->getQuery(true);
$query->select('field_name');
$query->from($db->quoteName('#__my_table'));
$query->where($db->quoteName('some_name')." = :value");
$query->bind(':value', $some_value);
$db->setQuery($query);
$result = $db->loadResult();
Single Row Results
Each of these results functions will return a single record from the database even though there may be several records that meet the criteria that you have set. To get more records, you need to call the function again.
id | name | username | |
---|---|---|---|
1 | John Smith | [email protected] | johnsmith |
2 | Magda Hellman | [email protected] | magdah |
3 | Yvonne de Gaulle | [email protected] | ydegaulle |
loadRow()
loadRow()
returns an indexed array from a single record in the table:
. . .
$db->setQuery($query);
$row = $db->loadRow();
print_r($row);
will give:
Array ( [0] => 1, [1] => John Smith, [2] => [email protected], [3] => johnsmith )
You can access the individual values by using:
$row['index'] // e.g. $row['2']
Notes:
- The array indices are numeric starting from zero.
- Whilst you can repeat the call to get further rows, one of the functions that returns multiple rows might be more useful.
loadAssoc()
loadAssoc()
returns an associated array from a single record in the table:
. . .
$db->setQuery($query);
$row = $db->loadAssoc();
print_r($row);
will give:
Array ( [id] => 1, [name] => John Smith, [email] => [email protected], [username] => johnsmith )
You can access the individual values by using:
$row['name'] // e.g. $row['email']
Whilst you can repeat the call to get further rows, one of the functions that returns multiple rows might be more useful.
loadObject()
loadObject()
returns a PHP object from a single record in the table:
. . .
$db->setQuery($query);
$result = $db->loadObject();
print_r($result);
will give:
stdClass Object ( [id] => 1, [name] => John Smith, [email] => [email protected], [username] => johnsmith )
You can access the individual values by using:
$result->index // e.g. $result->email
Whilst you can repeat the call to get further rows, one of the functions that returns multiple rows might be more useful.
Single Column Results
Each of these results functions will return a single column from the database.
id | name | username | |
---|---|---|---|
1 | John Smith | [email protected] | johnsmith |
2 | Magda Hellman | [email protected] | magdah |
3 | Yvonne de Gaulle | [email protected] | ydegaulle |
loadColumn()
loadColumn()
returns an indexed array from a single column in the table:
$query->select('name'));
->from . . .";
. . .
$db->setQuery($query);
$column = $db->loadColumn();
print_r($column);
will give:
Array ( [0] => John Smith, [1] => Magda Hellman, [2] => Yvonne de Gaulle )
You can access the individual values by using:
$column['index'] // e.g. $column['2']
- The array indices are numeric starting from zero.
loadColumn()
is equivalent toloadColumn(0)
.
loadColumn($index)
loadColumn($index)
returns an indexed array from a single column in the table:
$query->select(array('name', 'email', 'username'));
->from . . .";
. . .
$db->setQuery($query);
$column = $db->loadColumn(1);
print_r($column);
will give:
[
[0] => [email protected],
[1] => [email protected],
[2] => [email protected],
];
You can access the individual values by using:
$column['index'] // e.g. $column['2']
loadColumn($index)
allows you to iterate through a series of columns in the results:
. . .
$db->setQuery($query);
for ( $i = 0; $i <= 2; $i++ ) {
$column = $db->loadColumn($i);
print_r($column);
}
will give:
Array (
[0] => Array ( [0] => John Smith, [1] => Magda Hellman, [2] => Yvonne de Gaulle ),
[1] => Array ( [0] => [email protected], [1] => [email protected], [2] => [email protected] ),
[2] => Array ( [0] => johnsmith, [1] => magdah, [2] => ydegaulle )
)
The array indices are numeric starting from zero.
Multi-Row Results
Each of these results functions will return multiple records from the database.
id | name | username | |
---|---|---|---|
1 | John Smith | [email protected] | johnsmith |
2 | Magda Hellman | [email protected] | magdah |
3 | Yvonne de Gaulle | [email protected] | ydegaulle |
loadRowList()
loadRowList()
returns an indexed array of indexed arrays from the table records returned by the query:
. . .
$db->setQuery($query);
$row = $db->loadRowList();
print_r($row);
will give (with line breaks added for clarity):
Array (
[0] => Array ( [0] => 1, [1] => John Smith, [2] => [email protected], [3] => johnsmith ),
[1] => Array ( [0] => 2, [1] => Magda Hellman, [2] => [email protected], [3] => magdah ),
[2] => Array ( [0] => 3, [1] => Yvonne de Gaulle, [2] => [email protected], [3] => ydegaulle )
)
You can access the individual rows by using:
$row['index'] // e.g. $row['2']
and you can access the individual values by using:
$row['index']['index'] // e.g. $row['2']['3']
The array indices are numeric starting from zero.
loadAssocList()
loadAssocList()
returns an indexed array of associated arrays from the table records returned by the query:
. . .
$db->setQuery($query);
$row = $db->loadAssocList();
print_r($row);
will give (with line breaks added for clarity):
Array (
[0] => Array ( [id] => 1, [name] => John Smith, [email] => [email protected], [username] => johnsmith ),
[1] => Array ( [id] => 2, [name] => Magda Hellman, [email] => [email protected], [username] => magdah ),
[2] => Array ( [id] => 3, [name] => Yvonne de Gaulle, [email] => [email protected], [username] => ydegaulle )
)
You can access the individual rows by using:
$row['index'] // e.g. $row['2']
and you can access the individual values by using:
$row['index']['column_name'] // e.g. $row['2']['email']
loadAssocList($key)
loadAssocList($key)
returns an associated array - indexed on 'key' - of associated arrays
from the table records returned by the query:
. . .
$db->setQuery($query);
$row = $db->loadAssocList('username');
print_r($row);
will give (with line breaks added for clarity):
Array (
[johnsmith] => Array ( [id] => 1, [name] => John Smith, [email] => [email protected], [username] => johnsmith ),
[magdah] => Array ( [id] => 2, [name] => Magda Hellman, [email] => [email protected], [username] => magdah ),
[ydegaulle] => Array ( [id] => 3, [name] => Yvonne de Gaulle, [email] => [email protected], [username] => ydegaulle )
)
You can access the individual rows by using:
$row['key_value'] // e.g. $row['johnsmith']
and you can access the individual values by using:
$row['key_value']['column_name'] // e.g. $row['johnsmith']['email']
Key must be a valid column name from the table; it does not have to be an Index or a Primary Key. But if it does not have a unique value you may not be able to retrieve results reliably.
loadAssocList($key, $column)
loadAssocList('key', 'column')
returns an associative array, indexed on 'key', of values from the column named 'column' returned by the query:
. . .
$db->setQuery($query);
$row = $db->loadAssocList('id', 'username');
print_r($row);
will give (with line breaks added for clarity):
Array (
[1] => John Smith,
[2] => Magda Hellman,
[3] => Yvonne de Gaulle,
)
Key must be a valid column name from the table; it does not have to be an Index or a Primary Key. But if it does not have a unique value you may not be able to retrieve results reliably.
loadObjectList()
loadObjectList()
returns an indexed array of PHP objects from the table records returned by the query:
. . .
$db->setQuery($query);
$row = $db->loadObjectList();
print_r($row);
will give (with line breaks added for clarity):
Array (
[0] => stdClass Object ( [id] => 1, [name] => John Smith,
[email] => [email protected], [username] => johnsmith ),
[1] => stdClass Object ( [id] => 2, [name] => Magda Hellman,
[email] => [email protected], [username] => magdah ),
[2] => stdClass Object ( [id] => 3, [name] => Yvonne de Gaulle,
[email] => [email protected], [username] => ydegaulle )
)
You can access the individual rows by using:
$row['index'] // e.g. $row['2']
and you can access the individual values by using:
$row['index']->name // e.g. $row['2']->email
loadObjectList($key)
loadObjectList('key')
returns an associated array - indexed on 'key' - of objects from the table records returned by the query:
. . .
$db->setQuery($query);
$row = $db->loadObjectList('username');
print_r($row);
will give (with line breaks added for clarity):
Array (
[johnsmith] => stdClass Object ( [id] => 1, [name] => John Smith,
[email] => [email protected], [username] => johnsmith ),
[magdah] => stdClass Object ( [id] => 2, [name] => Magda Hellman,
[email] => [email protected], [username] => magdah ),
[ydegaulle] => stdClass Object ( [id] => 3, [name] => Yvonne de Gaulle,
[email] => [email protected], [username] => ydegaulle )
)
You can access the individual rows by using:
$row['key_value'] // e.g. $row['johnsmith']
and you can access the individual values by using:
$row['key_value']->column_name // e.g. $row['johnsmith']->email
Key must be a valid column name from the table; it does not have to be an Index or a Primary Key. But if it does not have a unique value you may not be able to retrieve results reliably.
Miscellaneous Result Set Methods
getNumRows()
getNumRows()
will return the number of result rows found by the last SELECT or SHOW query and waiting to be read. To get a result from getNumRows() you have to run it after the query and before you have retrieved any results. To retrieve the number of rows affected by a INSERT, UPDATE, REPLACE or DELETE query, use getAffectedRows()
.
. . .
$db->setQuery($query);
$db->execute();
$num_rows = $db->getNumRows();
print_r($num_rows);
$result = $db->loadRowList();
will return
3
getNumRows()
is only valid for statements like SELECT or SHOW that return an actual result set. If you run getNumRows()
after loadRowList()
- or any other retrieval method - you will get a PHP Warning:
Warning: mysql_num_rows(): 80 is not a valid MySQL result resource
in libraries\joomla\database\database\mysql.php on line 344