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authorxue <>2006-11-24 04:21:06 +0000
committerxue <>2006-11-24 04:21:06 +0000
commit9478fba18018c1f072f5f6dd4335c5828f23bc80 (patch)
treef3718d9fd6af53c8aebc591b047a1b257804fa17 /framework/Data/TDbCommand.php
parent750f6c453bb21d6cef0eed50ed742fe7048709d2 (diff)
Added DB layer.
Diffstat (limited to 'framework/Data/TDbCommand.php')
-rw-r--r--framework/Data/TDbCommand.php262
1 files changed, 262 insertions, 0 deletions
diff --git a/framework/Data/TDbCommand.php b/framework/Data/TDbCommand.php
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+<?php
+/**
+ * TDbCommand class file
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @link http://www.pradosoft.com/
+ * @copyright Copyright &copy; 2006 PradoSoft
+ * @license http://www.pradosoft.com/license/
+ * @version $Id $
+ * @package System.Data
+ */
+
+/**
+ * TDbCommand class.
+ *
+ * TDbCommand represents an SQL statement to execute against a database.
+ * It is usually created by calling {@link TDbConnection::createCommand}.
+ * The SQL statement to be executed may be set via {@link setText Text}.
+ *
+ * To execute a non-query SQL (such as insert, delete, update), call
+ * {@link execute}. To execute an SQL statement that returns result data set
+ * (such as select), use {@link query} or its convenient versions {@link queryRow}
+ * and {@link queryScalar}.
+ *
+ * TDbCommand supports SQL statment preparation and parameter binding.
+ * Call {@link bindParameter} to bind a PHP variable to a parameter in SQL.
+ * Call {@link bindValue} to bind a value to an SQL parameter.
+ * When binding a parameter, the SQL statement is automatically prepared.
+ * You may also call {@link prepare} to explicitly prepare an SQL statement.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @version $Id $
+ * @package System.Data
+ * @since 3.0
+ */
+class TDbCommand extends TComponent
+{
+ private $_connection;
+ private $_text='';
+ private $_statement=null;
+
+ /**
+ * Constructor.
+ * @param TDbConnection the database connection
+ * @param string the SQL statement to be executed
+ */
+ public function __construct(TDbConnection $connection,$text)
+ {
+ $this->_connection=$connection;
+ $this->setText($text);
+ }
+
+ /**
+ * @return string the SQL statement to be executed
+ */
+ public function getText()
+ {
+ return $this->_text;
+ }
+
+ /**
+ * Specifies the SQL statement to be executed.
+ * Any previous execution will be terminated or cancel.
+ * @param string the SQL statement to be executed
+ */
+ public function setText($value)
+ {
+ $this->_text=$value;
+ $this->cancel();
+ }
+
+ /**
+ * @return TDbConnection the connection associated with this command
+ */
+ public function getConnection()
+ {
+ return $this->_connection;
+ }
+
+ /**
+ * @return PDOStatement the underlying PDOStatement for this command
+ * It could be null if the statement is not created yet.
+ */
+ public function getPdoStatement()
+ {
+ return $this->_statement;
+ }
+
+ /**
+ * Prepares the SQL statement to be executed.
+ * For complex SQL statement that is to be executed multiple times,
+ * this may improve performance.
+ * For SQL statement with binding parameters, this method is invoked
+ * automatically.
+ */
+ public function prepare()
+ {
+ if($this->_statement==null)
+ {
+ try
+ {
+ $this->_statement=$this->getConnection()->getPdoInstance()->prepare($sql);
+ }
+ catch(Exception $e)
+ {
+ throw new TDbException('dbcommand_prepare_failed',$e->getMessage());
+ }
+ }
+ }
+
+ /**
+ * Cancels the execution of the SQL statement.
+ */
+ public function cancel()
+ {
+ $this->_statement=null;
+ }
+
+ /**
+ * Binds a parameter to the SQL statement to be executed.
+ * @param mixed Parameter identifier. For a prepared statement
+ * using named placeholders, this will be a parameter name of
+ * the form :name. For a prepared statement using question mark
+ * placeholders, this will be the 1-indexed position of the parameter.
+ * @param mixed Name of the PHP variable to bind to the SQL statement parameter
+ * @param int SQL data type of the parameter
+ * @param int length of the data type
+ * @see http://www.php.net/manual/en/function.pdostatement-bindparam.php
+ */
+ public function bindParameter($name, &$value, $dataType=null, $length=null)
+ {
+ $this->prepare();
+ if($dataType===null)
+ $this->_statement->bindParam($name,$value);
+ else if($length===null)
+ $this->_statement->bindParam($name,$value,$dataType);
+ else
+ $this->_statement->bindParam($name,$value,$dataType,$length);
+ }
+
+ /**
+ * Binds a value to a parameter.
+ * @param mixed Parameter identifier. For a prepared statement
+ * using named placeholders, this will be a parameter name of
+ * the form :name. For a prepared statement using question mark
+ * placeholders, this will be the 1-indexed position of the parameter.
+ * @param mixed The value to bind to the parameter
+ * @param int SQL data type of the parameter
+ * @see http://www.php.net/manual/en/function.pdostatement-bindvalue.php
+ */
+ public function bindValue($name, $value, $dataType=null)
+ {
+ $this->prepare();
+ if($dataType===null)
+ $this->_statement->bindParam($name,$value);
+ else
+ $this->_statement->bindParam($name,$value,$dataType);
+ }
+
+ /**
+ * Executes the SQL statement.
+ * This method is meant only for executing non-query SQL statement.
+ * No result set will be returned.
+ * @return integer number of rows affected by the execution.
+ * @throws TDbException execution failed
+ */
+ public function execute()
+ {
+ try
+ {
+ if($this->_statement instanceof PDOStatement)
+ {
+ $this->_statement->execute();
+ return $this->_statement->rowCount();
+ }
+ else
+ return $this->getConnection()->getPdoInstance()->exec($this->getText());
+ }
+ catch(Exception $e)
+ {
+ throw new TDbException('dbcommand_execute_failed',$e->getMessage());
+ }
+ }
+
+ /**
+ * Executes the SQL statement and returns query result.
+ * This method is for executing an SQL query that returns result set.
+ * @return TDbDataReader the reader object for fetching the query result
+ * @throws TDbException execution failed
+ */
+ public function query()
+ {
+ try
+ {
+ if($this->_statement instanceof PDOStatement)
+ $this->_statement->execute();
+ else
+ $this->_statement=$this->getConnection()->getPdoInstance()->query($this->getText());
+ return new TDbDataReader($this);
+ }
+ catch(Exception $e)
+ {
+ throw new TDbException('dbcommand_query_failed',$e->getMessage());
+ }
+ }
+
+ /**
+ * Executes the SQL statement and returns the first row of the result.
+ * This is a convenient method of {@link query} when only the first row of data is needed.
+ * @param boolean whether the row should be returned as an associated array with
+ * column names as the keys or the array keys are column indexes (0-based).
+ * @return array the first row of the query result, false if not result.
+ * @throws TDbException execution failed
+ */
+ public function queryRow($fetchAssociative=true)
+ {
+ try
+ {
+ if($this->_statement instanceof PDOStatement)
+ $this->_statement->execute();
+ else
+ $this->_statement=$this->getConnection()->getPdoInstance()->query($sql);
+ $result=$this->_statement->fetch($fetchAssociative ? PDO::FETCH_ASSOC : PDO::FETCH_NUM);
+ $this->_statement->closeCursor();
+ return $result;
+ }
+ catch(Exception $e)
+ {
+ throw new TDbException('dbcommand_query_failed',$e->getMessage());
+ }
+ }
+
+ /**
+ * Executes the SQL statement and returns the value of the first column in the first row of data.
+ * This is a convenient method of {@link query} when only a single scalar
+ * value is needed (e.g. obtaining the count of the records).
+ * @return mixed the value of the first column in the first row of the query result.
+ * @throws TDbException execution failed or there is no data
+ */
+ public function queryScalar()
+ {
+ try
+ {
+ if($this->_statement instanceof PDOStatement)
+ $this->_statement->execute();
+ else
+ $this->_statement=$this->getConnection()->getPdoInstance()->query($sql);
+ $result=$this->_statement->fetchColumn();
+ $this->_statement->closeCursor();
+ if($result!==false)
+ return $result;
+ else
+ throw new TDbException('dbcommand_column_empty');
+ }
+ catch(Exception $e)
+ {
+ throw new TDbException('dbcommand_queryscalar_failed',$e->getMessage());
+ }
+ }
+}
+
+?> \ No newline at end of file