HumHub Documentation (unofficial)

DataReader extends BaseObject
in package

Application

implements Iterator, Countable

DataReader represents a forward-only stream of rows from a query result set.

To read the current row of data, call [[read()]]. The method [[readAll()]] returns all the rows in a single array. Rows of data can also be read by iterating through the reader. For example,

$command = $connection->createCommand('SELECT * FROM post');
$reader = $command->query();

while ($row = $reader->read()) {
    $rows[] = $row;
}

// equivalent to:
foreach ($reader as $row) {
    $rows[] = $row;
}

// equivalent to:
$rows = $reader->readAll();

Note that since DataReader is a forward-only stream, you can only traverse it once. Doing it the second time will throw an exception.

It is possible to use a specific mode of data fetching by setting [[fetchMode]]. See the PHP manual for more details about possible fetch mode.

Interfaces

Iterator
Countable

Properties

$columnCount : int
$fetchMode : int
$isClosed : bool
$rowCount : int
$_closed : mixed
$_index : mixed
$_row : mixed
$_statement : PDOStatement

Methods

__call() : mixed: Calls the named method which is not a class method.
__construct() : mixed: Constructor.
__get() : mixed: Returns the value of an object property.
__isset() : bool: Checks if a property is set, i.e. defined and not null.
__set() : mixed: Sets value of an object property.
__unset() : mixed: Sets an object property to null.
bindColumn() : mixed: Binds a column to a PHP variable.
canGetProperty() : bool: Returns a value indicating whether a property can be read.
canSetProperty() : bool: Returns a value indicating whether a property can be set.
className() : string: Returns the fully qualified name of this class.
close() : mixed: Closes the reader.
count() : int: Returns the number of rows in the result set.
current() : mixed: Returns the current row.
getColumnCount() : int: Returns the number of columns in the result set.
getIsClosed() : bool: whether the reader is closed or not.
getRowCount() : int: Returns the number of rows in the result set.
hasMethod() : bool: Returns a value indicating whether a method is defined.
hasProperty() : bool: Returns a value indicating whether a property is defined.
init() : mixed: Initializes the object.
key() : int: Returns the index of the current row.
next() : mixed: Moves the internal pointer to the next row.
nextResult() : bool: Advances the reader to the next result when reading the results of a batch of statements.
read() : array<string|int, mixed>: Advances the reader to the next row in a result set.
readAll() : array<string|int, mixed>: Reads the whole result set into an array.
readColumn() : mixed: Returns a single column from the next row of a result set.
readObject() : mixed: Returns an object populated with the next row of data.
rewind() : mixed: Resets the iterator to the initial state.
setFetchMode() : mixed: Set the default fetch mode for this statement.
valid() : bool: Returns whether there is a row of data at current position.

$columnCount read-only


    public
        int
    $columnCount

The number of columns in the result set.

$fetchMode write-only


    public
        int
    $fetchMode

Fetch mode.

$isClosed read-only


    public
        bool
    $isClosed

Whether the reader is closed or not.

$rowCount read-only


    public
        int
    $rowCount

Number of rows contained in the result.

$_closed


    private
        mixed
    $_closed
     = false

$_index


    private
        mixed
    $_index
     = -1

$_row


    private
        mixed
    $_row

$_statement


    private
        PDOStatement
    $_statement

the PDOStatement associated with the command

__call()

Calls the named method which is not a class method.


    public
                    __call(string $name, array<string|int, mixed> $params) : mixed

Do not call this method directly as it is a PHP magic method that will be implicitly called when an unknown method is being invoked.

Parameters

$name : string: the method name
$params : array<string|int, mixed>: method parameters

Return values

mixed —

the method return value

__construct()

Constructor.


    public
                    __construct(Command $command[, array<string|int, mixed> $config = [] ]) : mixed

Parameters

$command : Command: the command generating the query result
$config : array<string|int, mixed> = []: name-value pairs that will be used to initialize the object properties

__get()

Returns the value of an object property.


    public
                    __get(string $name) : mixed

Do not call this method directly as it is a PHP magic method that will be implicitly called when executing $value = $object->property;.

Parameters

$name : string: the property name

Return values

mixed —

the property value

__isset()

Checks if a property is set, i.e. defined and not null.


    public
                    __isset(string $name) : bool

Do not call this method directly as it is a PHP magic method that will be implicitly called when executing isset($object->property).

Note that if the property is not defined, false will be returned.

Parameters

$name : string: the property name or the event name

Return values

bool —

whether the named property is set (not null).

__set()

Sets value of an object property.


    public
                    __set(string $name, mixed $value) : mixed

Do not call this method directly as it is a PHP magic method that will be implicitly called when executing $object->property = $value;.

Parameters

$name : string: the property name or the event name
$value : mixed: the property value

__unset()

Sets an object property to null.


    public
                    __unset(string $name) : mixed

Do not call this method directly as it is a PHP magic method that will be implicitly called when executing unset($object->property).

Note that if the property is not defined, this method will do nothing. If the property is read-only, it will throw an exception.

Parameters

$name : string: the property name

bindColumn()

Binds a column to a PHP variable.


    public
                    bindColumn(int|string $column, mixed &$value[, int|null $dataType = null ]) : mixed

When rows of data are being fetched, the corresponding column value will be set in the variable. Note, the fetch mode must include PDO::FETCH_BOUND.

Parameters

$column : int|string: Number of the column (1-indexed) or name of the column in the result set. If using the column name, be aware that the name should match the case of the column, as returned by the driver.
$value : mixed: Name of the PHP variable to which the column will be bound.
$dataType : int|null = null: Data type of the parameter

canGetProperty()

Returns a value indicating whether a property can be read.


    public
                    canGetProperty(string $name[, bool $checkVars = true ]) : bool

A property is readable if:

the class has a getter method associated with the specified name (in this case, property name is case-insensitive);
the class has a member variable with the specified name (when $checkVars is true);

Parameters

$name : string: the property name
$checkVars : bool = true: whether to treat member variables as properties

Return values

bool —

whether the property can be read

canSetProperty()

Returns a value indicating whether a property can be set.


    public
                    canSetProperty(string $name[, bool $checkVars = true ]) : bool

A property is writable if:

the class has a setter method associated with the specified name (in this case, property name is case-insensitive);
the class has a member variable with the specified name (when $checkVars is true);

Parameters

$name : string: the property name
$checkVars : bool = true: whether to treat member variables as properties

Return values

bool —

whether the property can be written

className()

Returns the fully qualified name of this class.


    public
            static        className() : string

Return values

string —

the fully qualified name of this class.

close()

Closes the reader.


    public
                    close() : mixed

This frees up the resources allocated for executing this SQL statement. Read attempts after this method call are unpredictable.

count()

Returns the number of rows in the result set.


    public
                    count() : int

This method is required by the Countable interface. Note, most DBMS may not give a meaningful count. In this case, use "SELECT COUNT(*) FROM tableName" to obtain the number of rows.

#[ReturnTypeWillChange]

Return values

int —

number of rows contained in the result.

current()

Returns the current row.


    public
                    current() : mixed

This method is required by the interface [[\Iterator]].

#[ReturnTypeWillChange]

Return values

mixed —

the current row.

getColumnCount()

Returns the number of columns in the result set.


    public
                    getColumnCount() : int

Note, even there's no row in the reader, this still gives correct column number.

Return values

int —

the number of columns in the result set.

getIsClosed()

whether the reader is closed or not.


    public
                    getIsClosed() : bool

Return values

bool —

whether the reader is closed or not.

getRowCount()

Returns the number of rows in the result set.


    public
                    getRowCount() : int

Note, most DBMS may not give a meaningful count. In this case, use "SELECT COUNT(*) FROM tableName" to obtain the number of rows.

Return values

int —

number of rows contained in the result.

hasMethod()

Returns a value indicating whether a method is defined.


    public
                    hasMethod(string $name) : bool

The default implementation is a call to php function method_exists(). You may override this method when you implemented the php magic method __call().

Parameters

$name : string: the method name

Return values

bool —

whether the method is defined

hasProperty()

Returns a value indicating whether a property is defined.


    public
                    hasProperty(string $name[, bool $checkVars = true ]) : bool

A property is defined if:

the class has a getter or setter method associated with the specified name (in this case, property name is case-insensitive);
the class has a member variable with the specified name (when $checkVars is true);

Parameters

$name : string: the property name
$checkVars : bool = true: whether to treat member variables as properties

Return values

bool —

whether the property is defined

init()

Initializes the object.


    public
                    init() : mixed

This method is invoked at the end of the constructor after the object is initialized with the given configuration.

key()

Returns the index of the current row.


    public
                    key() : int

This method is required by the interface [[\Iterator]].

#[ReturnTypeWillChange]

Return values

int —

the index of the current row.

next()

Moves the internal pointer to the next row.


    public
                    next() : mixed

This method is required by the interface [[\Iterator]].

#[ReturnTypeWillChange]

nextResult()

Advances the reader to the next result when reading the results of a batch of statements.


    public
                    nextResult() : bool

This method is only useful when there are multiple result sets returned by the query. Not all DBMS support this feature.

Return values

bool —

Returns true on success or false on failure.

read()

Advances the reader to the next row in a result set.


    public
                    read() : array<string|int, mixed>

Return values

array<string|int, mixed> —

the current row, false if no more row available

readAll()

Reads the whole result set into an array.


    public
                    readAll() : array<string|int, mixed>

Return values

array<string|int, mixed> —

the result set (each array element represents a row of data). An empty array will be returned if the result contains no row.

readColumn()

Returns a single column from the next row of a result set.


    public
                    readColumn(int $columnIndex) : mixed

Parameters

$columnIndex : int: zero-based column index

Return values

mixed —

the column of the current row, false if no more rows available

readObject()

Returns an object populated with the next row of data.


    public
                    readObject(string $className, array<string|int, mixed> $fields) : mixed

Parameters

$className : string: class name of the object to be created and populated
$fields : array<string|int, mixed>: Elements of this array are passed to the constructor

Return values

mixed —

the populated object, false if no more row of data available

rewind()

Resets the iterator to the initial state.


    public
                    rewind() : mixed

This method is required by the interface [[\Iterator]].

setFetchMode()

Set the default fetch mode for this statement.


    public
                    setFetchMode(int $mode) : mixed

Parameters

$mode : int: fetch mode

valid()

Returns whether there is a row of data at current position.


    public
                    valid() : bool

This method is required by the interface [[\Iterator]].

#[ReturnTypeWillChange]

Return values

bool —

whether there is a row of data at current position.

DataReader extends BaseObject in package Application implements Iterator, Countable

Tags

Table of Contents

Interfaces

Properties

Methods

Properties

$columnCount read-only

$fetchMode write-only

$isClosed read-only

$rowCount read-only

$_closed

$_index

$_row

$_statement

Methods

__call()

Parameters

Tags

Return values

__construct()

Parameters

__get()

Parameters

Tags

Return values

__isset()

Parameters

Tags

Return values

__set()

Parameters

Tags

__unset()

Parameters

Tags

bindColumn()

Parameters

Tags

canGetProperty()

Parameters

Tags

Return values

canSetProperty()

Parameters

Tags

Return values

className()

Tags

Return values

close()

count()

Attributes

Return values

current()

Attributes

Return values

getColumnCount()

Return values

getIsClosed()

Return values

getRowCount()

Return values

hasMethod()

Parameters

Return values

hasProperty()

Parameters

Tags

Return values

init()

key()

Attributes

DataReader extends BaseObject
in package

Application

implements Iterator, Countable