mysql - 如何使用 Zend Adapter 从数据库中检索信息

Question

我正在尝试了解 Zend Adapter 的基本要素。教程和解释令人困惑，需要更多说明。谁能给我一些简单的例子来完全理解如何使用 SQL 查询以及如何获得所需的 SQL 结果？

特别是，我有兴趣学习如何获得

-- 列名

-- 表名

-- 获取所有条目

等等

谢谢，

Answer 1

像许多其他人一样，您似乎对快速入门有困难，请尝试来自 Rob Allen 的教程它帮助我入门。

关于如何连接到您的表，您有多种选择，与 Zend_Db 的混淆通常从这里开始。

使用一个数据库时，最简单的方法是在您的 application.ini 文件中至少添加以下行:

resources.db.adapter = "pdo_Mysql"
resources.db.params.username = "user_name"
resources.db.params.password = "password"
resources.db.params.dbname = "db_name"

或者，您几乎可以在代码的任何位置使用 Zend_Db_Adapter 连接到数据库。 :

//using a normal constructor
$db = new Zend_Db_Adapter_Pdo_Mysql(array(
    'host'     => '127.0.0.1',
    'username' => 'webuser',
    'password' => 'xxxxxxxx',
    'dbname'   => 'test'
));

//using factory
$db = Zend_Db::factory('Pdo_Mysql', array(
    'host'     => '127.0.0.1',
    'username' => 'webuser',
    'password' => 'xxxxxxxx',
    'dbname'   => 'test'
));

List of supported Databases

在您的应用程序中使用它可以很简单:

//fetchAll using Zend_Db_Adapter and plain SQL
$sql = 'SELECT * FROM bugs WHERE bug_id = ?';

$result = $db->fetchAll($sql, 2);

您可以列出数据库中的表:

$tables = $db->listTables();

或者你可以获得完整的表描述(包括列名)，我在 Zend_Db_Adapter_Abstract 中包含了函数的注释 block :

 /**
     * Returns the column descriptions for a table.
     *
     * The return value is an associative array keyed by the column name,
     * as returned by the RDBMS.
     *
     * The value of each array element is an associative array
     * with the following keys:
     *
     * SCHEMA_NAME => string; name of database or schema
     * TABLE_NAME  => string;
     * COLUMN_NAME => string; column name
     * COLUMN_POSITION => number; ordinal position of column in table
     * DATA_TYPE   => string; SQL datatype name of column
     * DEFAULT     => string; default expression of column, null if none
     * NULLABLE    => boolean; true if column can have nulls
     * LENGTH      => number; length of CHAR/VARCHAR
     * SCALE       => number; scale of NUMERIC/DECIMAL
     * PRECISION   => number; precision of NUMERIC/DECIMAL
     * UNSIGNED    => boolean; unsigned property of an integer type
     * PRIMARY     => boolean; true if column is part of the primary key
     * PRIMARY_POSITION => integer; position of column in primary key
     *
     * @param string $tableName
     * @param string $schemaName OPTIONAL
     * @return array
     */
$describTable = $db->describeTable('myTable');

此信息应该可以帮助您入门，但是我发现 Zend_Db 的很多真正的力量在于 Zend_Db_Table , Zend_Db_Table_Row尤其是 Zend_Db_Select类。

我敦促您花一些时间弄清楚它们。

作为您可能对 Zend_Db_Table 和 Zend_Db_select 的期望的示例(当不使用更高级的映射器和域对象时，希望它们会在以后出现):

//When using DbTable models that extend Zend_Db_Table_Abstract the model already 
//knows the name of the table and has full access to the Db adapter, allowing your code to
//be very brief and descriptive.
class Application_Model_DbTable_Weekend extends Zend_Db_Table_Abstract
{
    //name of table, required if classname is not the same as the table name
    protected $_name = 'weekend';
    //primary key column of table, a good idea especially if primary key is not 'id'
    protected $_primary = 'weekendid';

    public function getWeekend($weekendId) {
        //create select object
        $select = $this->select();
        $select->where('weekendid = ?', $weekendId);//placeholder syntax

        $result = $this->fetchRow($select);       
        if (!$result) {
            throw new Exception('Could not find weekend ID ' . $weekendId);
        }
        return $result;//returns a single row object
    }
    public function fetchAllWeekend() {

        $select = $this->select();

        $result = $this->fetchAll($select);

        return $result; //returns array of row objects (rowset object)
    }
}

Rob Allen 的 Zf 教程将解释 DbTable 模型的设置方式及其工作原理。

希望这有助于...