You can call methods on the statement object to retrieve rows from
SQL statements that produce result set. SELECT,
SHOW, DESCRIBE and EXPLAIN are
examples of statements that produce a result set. INSERT,
UPDATE, and DELETE are examples of statements that
don't produce a result set. You can execute the latter SQL statements
using Zend_Db_Statement, but you cannot call methods to fetch
rows of results from them.
To retrieve one row from the result set, use the
fetch() method of the statement object.
All three arguments of this method are optional:
Fetch style is the first argument. This controls the structure in which the row is returned. See this chapter for a description of the valid values and the corresponding data formats.
Cursor orientation is the second argument. The default is
Zend_Db::FETCH_ORI_NEXT, which simply means that each call tofetch()returns the next row in the result set, in the order returned by the RDBMS.Offset is the third argument. If the cursor orientation is
Zend_Db::FETCH_ORI_ABS, then the offset number is the ordinal number of the row to return. If the cursor orientation isZend_Db::FETCH_ORI_REL, then the offset number is relative to the cursor position beforefetch()was called.
fetch() returns FALSE if all rows of
the result set have been fetched.
Example 219. Using fetch() in a loop
<?php
$stmt = $db->query('SELECT * FROM bugs');
while ($row = $stmt->fetch()) {
echo $row['bug_description'];
}
See also PDOStatement::fetch().
To retrieve all the rows of the result set in one step, use the
fetchAll() method. This is equivalent to calling
the fetch() method in a loop and returning all
the rows in an array. The fetchAll() method accepts
two arguments. The first is the fetch style, as described above,
and the second indicates the number of the column to return,
when the fetch style is Zend_Db::FETCH_COLUMN.
Example 220. Using fetchAll()
<?php
$stmt = $db->query('SELECT * FROM bugs');
$rows = $stmt->fetchAll();
echo $rows[0]['bug_description'];
See also PDOStatement::fetchAll().
By default, the statement object returns rows of the result set
as associative arrays, mapping column names to column values.
You can specify a different format for the statement class to
return rows, just as you can in the Adapter class. You can use
the setFetchMode() method of the statement object
to specify the fetch mode. Specify the fetch mode using
Zend_Db class constants FETCH_ASSOC,
FETCH_NUM, FETCH_BOTH,
FETCH_COLUMN, and FETCH_OBJ.
See this chapter
for more information on these modes. Subsequent calls to the statement methods
fetch() or fetchAll() use the
fetch mode that you specify.
Example 221. Setting the fetch mode
<?php
$stmt = $db->query('SELECT * FROM bugs');
$stmt->setFetchMode(Zend_Db::FETCH_NUM);
$rows = $stmt->fetchAll();
echo $rows[0][0];
See also PDOStatement::setFetchMode().
To return a single column from the next row of the result set,
use fetchColumn(). The optional argument is the
integer index of the column, and it defaults to 0. This method
returns a scalar value, or FALSE if all rows of
the result set have been fetched.
Note this method operates differently than the
fetchCol() method of the Adapter class.
The fetchColumn() method of a statement returns a
single value from one row.
The fetchCol() method of an adapter returns an
array of values, taken from the first column of all rows of the
result set.
Example 222. Using fetchColumn()
<?php
$stmt = $db->query('SELECT bug_id, bug_description, bug_status FROM bugs');
$bug_status = $stmt->fetchColumn(2);
See also PDOStatement::fetchColumn().
To retrieve a row from the result set structured as an object,
use the fetchObject(). This method takes two
optional arguments. The first argument is a string that names
the class name of the object to return; the default is
'stdClass'. The second argument is an array of values that
will be passed to the constructor of that class.
Example 223. Using fetchObject()
<?php
$stmt = $db->query('SELECT bug_id, bug_description, bug_status FROM bugs');
$obj = $stmt->fetchObject();
echo $obj->bug_description;
See also PDOStatement::fetchObject().