Generating Query Results
There are several ways to generate query results:
Result Arrays
getResult()
This method returns the query result as an array of objects, or an empty array on failure.
Getting an Array of stdClass
Typically you’ll use this in a foreach loop, like this:
<?php
$query = $db->query('YOUR QUERY');
foreach ($query->getResult() as $row) {
echo $row->title;
echo $row->name;
echo $row->body;
}
The above method is an alias of CodeIgniter\Database\BaseResult::getResultObject()
.
Getting an Array of Array
You can pass in the string ‘array’ if you wish to get your results as an array of arrays:
<?php
$query = $db->query('YOUR QUERY');
foreach ($query->getResult('array') as $row) {
echo $row['title'];
echo $row['name'];
echo $row['body'];
}
The above usage is an alias of getResultArray().
Getting an Array of Custom Object
You can also pass a string to getResult()
which represents a class to
instantiate for each result object
<?php
$query = $db->query('SELECT * FROM users;');
foreach ($query->getResult(\App\Entities\User::class) as $user) {
echo $user->name; // access attributes
echo $user->reverseName(); // or methods defined on the 'User' class
}
The above method is an alias of getCustomResultObject().
getResultArray()
This method returns the query result as a pure array, or an empty array when no result is produced. Typically you’ll use this in a foreach loop, like this:
<?php
$query = $db->query('YOUR QUERY');
foreach ($query->getResultArray() as $row) {
echo $row['title'];
echo $row['name'];
echo $row['body'];
}
Result Rows
getRow()
This method returns a single result row. If your query has more than one row, it returns only the first row. The result is returned as an object. Here’s a usage example:
<?php
$query = $db->query('YOUR QUERY');
$row = $query->getRow();
if (isset($row)) {
echo $row->title;
echo $row->name;
echo $row->body;
}
If you want a specific row returned you can submit the row number as a digit in the first parameter:
<?php
$row = $query->getRow(5);
You can also add a second String parameter, which is the name of a class to instantiate the row with:
<?php
$query = $db->query('SELECT * FROM users LIMIT 1;');
$row = $query->getRow(0, \App\Entities\User::class);
echo $row->name; // access attributes
echo $row->reverse_name(); // or methods defined on the 'User' class
getRowArray()
Identical to the above row()
method, except it returns an array.
Example:
<?php
$query = $db->query('YOUR QUERY');
$row = $query->getRowArray();
if (isset($row)) {
echo $row['title'];
echo $row['name'];
echo $row['body'];
}
If you want a specific row returned you can submit the row number as a digit in the first parameter:
<?php
$row = $query->getRowArray(5);
In addition, you can walk forward/backward/first/last through your results using these variations:
$row = $query->getFirstRow()
$row = $query->getLastRow()
$row = $query->getNextRow()
$row = $query->getPreviousRow()
By default they return an object unless you put the word “array” in the parameter:
$row = $query->getFirstRow('array')
$row = $query->getLastRow('array')
$row = $query->getNextRow('array')
$row = $query->getPreviousRow('array')
Note
All the methods above will load the whole result into memory
(prefetching). Use getUnbufferedRow()
for processing large
result sets.
getUnbufferedRow()
This method returns a single result row without prefetching the whole
result in memory as row()
does. If your query has more than one row,
it returns the current row and moves the internal data pointer ahead.
<?php
$query = $db->query('YOUR QUERY');
while ($row = $query->getUnbufferedRow()) {
echo $row->title;
echo $row->name;
echo $row->body;
}
For use with MySQLi you may set MySQLi’s result mode to
MYSQLI_USE_RESULT
for maximum memory savings. Use of this is not
generally recommended but it can be beneficial in some circumstances
such as writing large queries to csv. If you change the result mode
be aware of the tradeoffs associated with it.
<?php
$db->resultMode = MYSQLI_USE_RESULT; // for unbuffered results
$query = $db->query('YOUR QUERY');
$file = new \CodeIgniter\Files\File(WRITEPATH . 'data.csv');
$csv = $file->openFile('w');
while ($row = $query->getUnbufferedRow('array')) {
$csv->fputcsv($row);
}
$db->resultMode = MYSQLI_STORE_RESULT; // return to default mode
Note
When using MYSQLI_USE_RESULT
all subsequent calls on the same
connection will result in error until all records have been fetched or
a freeResult()
call has been made. The getNumRows()
method will only
return the number of rows based on the current position of the data pointer.
MyISAM tables will remain locked until all the records have been fetched
or a freeResult()
call has been made.
You can optionally pass ‘object’ (default) or ‘array’ in order to specify the returned value’s type:
<?php
$query->getUnbufferedRow(); // object
$query->getUnbufferedRow('object'); // object
$query->getUnbufferedRow('array'); // associative array
Custom Result Objects
You can have the results returned as an instance of a custom class instead
of a stdClass
or array, as the getResult()
and getResultArray()
methods allow. If the class is not already loaded into memory, the Autoloader
will attempt to load it. The object will have all values returned from the
database set as properties. If these have been declared and are non-public
then you should provide a __set()
method to allow them to be set.
Example:
<?php
namespace App\Entities;
class User
{
public $id;
public $email;
public $username;
protected $lastLogin;
public function lastLogin($format)
{
return $this->lastLogin->format($format);
}
public function __set($name, $value)
{
if ($name === 'lastLogin') {
$this->lastLogin = DateTime::createFromFormat('!U', $value);
}
}
public function __get($name)
{
if (isset($this->{$name})) {
return $this->{$name};
}
}
}
In addition to the two methods listed below, the following methods also can
take a class name to return the results as: getFirstRow()
, getLastRow()
,
getNextRow()
, and getPreviousRow()
.
getCustomResultObject()
Returns the entire result set as an array of instances of the class requested. The only parameter is the name of the class to instantiate.
Example:
<?php
$query = $db->query('YOUR QUERY');
$rows = $query->getCustomResultObject(\App\Entities\User::class);
foreach ($rows as $row) {
echo $row->id;
echo $row->email;
echo $row->lastLogin('Y-m-d');
}
getCustomRowObject()
Returns a single row from your query results. The first parameter is the row number of the results. The second parameter is the class name to instantiate.
Example:
<?php
$query = $db->query('YOUR QUERY');
$row = $query->getCustomRowObject(0, \App\Entities\User::class);
if (isset($row)) {
echo $row->email; // access attributes
echo $row->lastLogin('Y-m-d'); // access class methods
}
You can also use the getRow()
method in exactly the same way.
Example:
<?php
$row = $query->getRow(0, \App\Entities\User::class);
Result Helper Methods
getFieldCount()
The number of FIELDS (columns) returned by the query. Make sure to call the method using your query result object:
<?php
$query = $db->query('SELECT * FROM my_table');
echo $query->getFieldCount();
getFieldNames()
Returns an array with the names of the FIELDS (columns) returned by the query. Make sure to call the method using your query result object:
<?php
$query = $db->query('SELECT * FROM my_table');
echo $query->getFieldNames();
getNumRows()
The number of records returned by the query. Make sure to call the method using your query result object:
<?php
$query = $db->query('SELECT * FROM my_table');
echo $query->getNumRows();
Note
Because SQLite3 lacks an efficient method returning a record count, CodeIgniter will fetch and buffer the query result records internally and return a count of the resulting record array, which can be inefficient.
freeResult()
It frees the memory associated with the result and deletes the result resource ID. Normally PHP frees its memory automatically at the end of script execution. However, if you are running a lot of queries in a particular script you might want to free the result after each query result has been generated in order to cut down on memory consumption.
Example:
<?php
$query = $thisdb->query('SELECT title FROM my_table');
foreach ($query->getResult() as $row) {
echo $row->title;
}
$query->freeResult(); // The $query result object will no longer be available
$query2 = $db->query('SELECT name FROM some_table');
$row = $query2->getRow();
echo $row->name;
$query2->freeResult(); // The $query2 result object will no longer be available
dataSeek()
This method sets the internal pointer for the next result row to be
fetched. It is only useful in combination with getUnbufferedRow()
.
It accepts a positive integer value, which defaults to 0 and returns true on success or false on failure.
<?php
$query = $db->query('SELECT `field_name` FROM `table_name`');
$query->dataSeek(5); // Skip the first 5 rows
$row = $query->getUnbufferedRow();
Note
Not all database drivers support this feature and will return false. Most notably - you won’t be able to use it with PDO.
Class Reference
- class CodeIgniter\Database\BaseResult
- getResult([$type = 'object'])
- Parameters:
$type (
string
) – Type of requested results - array, object, or class name
- Returns:
Array containing the fetched rows
- Return type:
array
A wrapper for the
getResultArray()
,getResultObject()
andgetCustomResultObject()
methods.Usage: see Result Arrays.
- getResultArray()
- Returns:
Array containing the fetched rows
- Return type:
array
Returns the query results as an array of rows, where each row is itself an associative array.
Usage: see Result Arrays.
- getResultObject()
- Returns:
Array containing the fetched rows
- Return type:
array
Returns the query results as an array of rows, where each row is an object of type
stdClass
.Usage: see Getting an Array of stdClass.
- getCustomResultObject($class_name)
- Parameters:
$class_name (
string
) – Class name for the resulting rows
- Returns:
Array containing the fetched rows
- Return type:
array
Returns the query results as an array of rows, where each row is an instance of the specified class.
- getRow([$n = 0[, $type = 'object']])
- Parameters:
$n (
int
) – Index of the query results row to be returned$type (
string
) – Type of the requested result - array, object, or class name
- Returns:
The requested row or null if it doesn’t exist
- Return type:
mixed
A wrapper for the
getRowArray()
,getRowObject()
andgetCustomRowObject()
methods.Usage: see Result Rows.
- getUnbufferedRow([$type = 'object'])
- Parameters:
$type (
string
) – Type of the requested result - array, object, or class name
- Returns:
Next row from the result set or null if it doesn’t exist
- Return type:
mixed
Fetches the next result row and returns it in the requested form.
Usage: see Result Rows.
- getRowArray([$n = 0])
- Parameters:
$n (
int
) – Index of the query results row to be returned
- Returns:
The requested row or null if it doesn’t exist
- Return type:
array
Returns the requested result row as an associative array.
Usage: see Result Rows.
- getRowObject([$n = 0])
- Parameters:
$n (
int
) – Index of the query results row to be returned :returns: The requested row or null if it doesn’t exist
- Return type:
stdClass
Returns the requested result row as an object of type
stdClass
.Usage: see Result Rows.
- getCustomRowObject($n, $type)
- Parameters:
$n (
int
) – Index of the results row to return$class_name (
string
) – Class name for the resulting row
- Returns:
The requested row or null if it doesn’t exist
- Return type:
$type
Returns the requested result row as an instance of the requested class.
- dataSeek([$n = 0])
- Parameters:
$n (
int
) – Index of the results row to be returned next
- Returns:
true on success, false on failure
- Return type:
bool
Moves the internal results row pointer to the desired offset.
Usage: see Result Helper Methods.
- setRow($key[, $value = null])
- Parameters:
$key (
mixed
) – Column name or array of key/value pairs$value (
mixed
) – Value to assign to the column, $key is a single field name
- Return type:
void
Assigns a value to a particular column.
- getNextRow([$type = 'object'])
- Parameters:
$type (
string
) – Type of the requested result - array, object, or class name
- Returns:
Next row of result set, or null if it doesn’t exist
- Return type:
mixed
Returns the next row from the result set.
- getPreviousRow([$type = 'object'])
- Parameters:
$type (
string
) – Type of the requested result - array, object, or class name
- Returns:
Previous row of result set, or null if it doesn’t exist
- Return type:
mixed
Returns the previous row from the result set.
- getFirstRow([$type = 'object'])
- Parameters:
$type (
string
) – Type of the requested result - array, object, or class name
- Returns:
First row of result set, or null if it doesn’t exist
- Return type:
mixed
Returns the first row from the result set.
- getLastRow([$type = 'object'])
- Parameters:
$type (
string
) – Type of the requested result - array, object, or class name
- Returns:
Last row of result set, or null if it doesn’t exist
- Return type:
mixed
Returns the last row from the result set.
- getFieldCount()
- Returns:
Number of fields in the result set
- Return type:
int
Returns the number of fields in the result set.
Usage: see Result Helper Methods.
- getFieldNames()
- Returns:
Array of column names
- Return type:
array
Returns an array containing the field names in the result set.
- getFieldData()
- Returns:
Array containing field meta-data
- Return type:
array
Generates an array of
stdClass
objects containing field meta-data.
- getNumRows()
- Returns:
Number of rows in result set
- Return type:
int
Returns number of rows returned by the query
- freeResult()
- Return type:
void
Frees a result set.
Usage: see Result Helper Methods.