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diff --git a/demos/quickstart/protected/pages/Database/SqlMap.page b/demos/quickstart/protected/pages/Database/SqlMap.page index 2b70e8f5..4b462168 100644 --- a/demos/quickstart/protected/pages/Database/SqlMap.page +++ b/demos/quickstart/protected/pages/Database/SqlMap.page @@ -3,78 +3,78 @@ <h1>Data Mapper</h1> <p>Data Mappers moves data between objects and a database while keeping them - independent of each other and the mapper itself. If you started with - <a href="?page=Database.ActiveRecord">Active Records</a>, you may eventually - faced with more complex business - objects as your project progresses. When you build an object model with a - lot of business logic it's valuable to use these mechanisms to better organize - the data and the behavior that goes with it. Doing so leads to variant schemas; - that is, the object schema and the relational schema don't match up. + independent of each other and the mapper itself. If you started with + <a href="?page=Database.ActiveRecord">Active Records</a>, you may eventually + faced with more complex business + objects as your project progresses. When you build an object model with a + lot of business logic it's valuable to use these mechanisms to better organize + the data and the behavior that goes with it. Doing so leads to variant schemas; + that is, the object schema and the relational schema don't match up. </p> <p>The Data Mapper separates the in-memory objects from the database. Its responsibility - is to transfer data between the two and also to isolate them from each other. - With Data Mapper the in-memory objects needn't know even that there's a database - present; they need no SQL interface code, and certainly no knowledge of the - database schema. (The database schema is always ignorant of the objects that use it.) + is to transfer data between the two and also to isolate them from each other. + With Data Mapper the in-memory objects needn't know even that there's a database + present; they need no SQL interface code, and certainly no knowledge of the + database schema. (The database schema is always ignorant of the objects that use it.) </p> <h2>When to Use It</h2> <p>The primary occasion for using Data Mapper is when you want the database schema - and the object model to evolve independently. Data Mapper's primary benefit is - that when working on the business (or domain) objects you can ignore the database, both in - design and in the build and testing process. The domain objects have no idea - what the database structure is, because all the correspondence is done by the mappers. + and the object model to evolve independently. Data Mapper's primary benefit is + that when working on the business (or domain) objects you can ignore the database, both in + design and in the build and testing process. The domain objects have no idea + what the database structure is, because all the correspondence is done by the mappers. </p> <p>This helps you in the code because you can understand and work with the domain objects - without having to understand how they're stored in the database. You can modify the - business models or the database without having to alter either. With complicated - mappings, particularly those involving <b>existing databases</b>, this is very valuable. + without having to understand how they're stored in the database. You can modify the + business models or the database without having to alter either. With complicated + mappings, particularly those involving <b>existing databases</b>, this is very valuable. </p> <p>The price, of course, is the extra layer that you don't get with - <a href="?page=Database.ActiveRecord">Active Record</a>, - so the test for using these patterns is the complexity of the business logic. - If you have fairly simple business logic, an <a href="?page=Database.ActiveRecord">Active Record</a> - will probably work. - For more complicated logic a Data Mapper may be more suitable. + <a href="?page=Database.ActiveRecord">Active Record</a>, + so the test for using these patterns is the complexity of the business logic. + If you have fairly simple business logic, an <a href="?page=Database.ActiveRecord">Active Record</a> + will probably work. + For more complicated logic a Data Mapper may be more suitable. </p> <h2>SqlMap Data Mapper</h2> <p>The SqlMap DataMapper framework makes it easier to use a database with a PHP application. - SqlMap DataMapper couples objects with stored procedures or SQL statements using - a XML descriptor. Simplicity is the biggest advantage of the SqlMap DataMapper over - object relational mapping tools. To use SqlMap DataMapper you rely on your own objects, - XML, and SQL. There is little to learn that you don't already know. - With SqlMap DataMapper you have the full power of both SQL and stored procedures at - your fingertip + SqlMap DataMapper couples objects with stored procedures or SQL statements using + a XML descriptor. Simplicity is the biggest advantage of the SqlMap DataMapper over + object relational mapping tools. To use SqlMap DataMapper you rely on your own objects, + XML, and SQL. There is little to learn that you don't already know. + With SqlMap DataMapper you have the full power of both SQL and stored procedures at + your fingertip </p> <p> - <img src=<%~ diagram.png %> alt="SqlMap Data Mapper Overview" id="fig:sqlmap.png" class="figure"/> - - Here's a high level description of the work flow illustrated in the figure abov. - Provide a parameter, either as an object or a primitive type. The parameter can be - used to set runtime values in your SQL statement or stored procedure. If a runtime value - is not needed, the parameter can be omitted. + <img src=<%~ diagram.png %> alt="SqlMap Data Mapper Overview" id="fig:sqlmap.png" class="figure"/> + + Here's a high level description of the work flow illustrated in the figure abov. + Provide a parameter, either as an object or a primitive type. The parameter can be + used to set runtime values in your SQL statement or stored procedure. If a runtime value + is not needed, the parameter can be omitted. </p> <p>Execute the mapping by passing the parameter and the name you gave the statement or - procedure in your XML descriptor. This step is where the magic happens. The framework - will prepare the SQL statement or stored procedure, set any runtime values using your - parameter, execute the procedure or statement, and return the result. + procedure in your XML descriptor. This step is where the magic happens. The framework + will prepare the SQL statement or stored procedure, set any runtime values using your + parameter, execute the procedure or statement, and return the result. </p> <p>In the case of an update, the number of rows affected is returned. In the case of a - query, a single object, or a collection of objects is returned. Like the parameter, - the result object, or collection of objects, can be a plain-old object or a primitive PHP type. + query, a single object, or a collection of objects is returned. Like the parameter, + the result object, or collection of objects, can be a plain-old object or a primitive PHP type. </p> <h2>Setting up a database connection and initializing the SqlMap</h2> <p> - A database connection for SqlMap can be set as follows. - See <a href="?page=Database.DAO">Establishing Database Connection</a> for - futher details regarding creation of database connection in general. + A database connection for SqlMap can be set as follows. + See <a href="?page=Database.DAO">Establishing Database Connection</a> for + futher details regarding creation of database connection in general. <com:TTextHighlighter Language="php" CssClass="source"> //create a connection and give it to the SqlMap manager. $dsn = 'pgsql:host=localhost;dbname=test'; //Postgres SQL @@ -82,21 +82,21 @@ $conn = new TDbConnection($dsn, 'dbuser','dbpass'); $manager = new TSqlMapManager($conn); $manager->configureXml('my-sqlmap.xml'); $sqlmap = $manager->getSqlMapGateway(); -</com:TTextHighlighter> +</com:TTextHighlighter> </p> <p> - The <tt>TSqlMapManager</tt> is responsible for setting up the database connection - and configuring the SqlMap with given XML file(s). The <tt>configureXml()</tt> - method accepts a string that points to a SqlMap XML configuration file. Once - configured, call the <tt>getSqlMapGateway()</tt> method to obtain an instance - of the SqlMap gateway interface (use this object to insert/delete/find records). + The <tt>TSqlMapManager</tt> is responsible for setting up the database connection + and configuring the SqlMap with given XML file(s). The <tt>configureXml()</tt> + method accepts a string that points to a SqlMap XML configuration file. Once + configured, call the <tt>getSqlMapGateway()</tt> method to obtain an instance + of the SqlMap gateway interface (use this object to insert/delete/find records). </p> <p> - SqlMap database connection can also be configured using a <tt><module></tt> - tag in the <a href="?page=Configurations.AppConfig">application.xml</a> - or <a href="?page=Configurations.PageConfig">config.xml</a> as follows. + SqlMap database connection can also be configured using a <tt><module></tt> + tag in the <a href="?page=Configurations.AppConfig">application.xml</a> + or <a href="?page=Configurations.PageConfig">config.xml</a> as follows. <com:TTextHighlighter Language="xml" CssClass="source"> <modules> <module id="my-sqlmap" class="System.Data.SqlMap.TSqlMapConfig" @@ -104,66 +104,66 @@ $sqlmap = $manager->getSqlMapGateway(); <database ConnectionString="pgsql:host=localhost;dbname=test" Username="dbuser" Password="dbpass" /> </module> -</modules> -</com:TTextHighlighter> +</modules> +</com:TTextHighlighter> </p> <p> - The <tt>ConfigFile</tt> attribute should point to a SqlMap configuration file - (to be detailed later) either using absolute path, relative path or the - Prado's namespace dot notation path (must omit the ".xml" extension). - - <div class="tip"><b class="note">Tip:</b> - The <tt>EnableCache</tt> attribute when set to "true" will cache the - parsed configuration. You must clear or disable the cache if you - make chanages your configuration file. - A <a href="?page=Advanced.Performance#6402">cache - module</a> must also be defined for the cache to function. - </div> + The <tt>ConfigFile</tt> attribute should point to a SqlMap configuration file + (to be detailed later) either using absolute path, relative path or the + Prado's namespace dot notation path (must omit the ".xml" extension). + + <div class="tip"><b class="note">Tip:</b> + The <tt>EnableCache</tt> attribute when set to "true" will cache the + parsed configuration. You must clear or disable the cache if you + make chanages your configuration file. + A <a href="?page=Advanced.Performance#6402">cache + module</a> must also be defined for the cache to function. + </div> </p> <p>To obtain the SqlMap gateway interface from the <module> configuration, simply - do, for example, + do, for example, <com:TTextHighlighter Language="php" CssClass="source"> class MyPage extends TPage { - public function onLoad($param) - { - parent::onLoad($param); - $sqlmap = $this->Application->Modules['my-sqlmap']->Client; - $sqlmap->queryForObject(...); //query for some object - } + public function onLoad($param) + { + parent::onLoad($param); + $sqlmap = $this->Application->Modules['my-sqlmap']->Client; + $sqlmap->queryForObject(...); //query for some object + } } </com:TTextHighlighter> </p> <h2>A quick example</h2> <p>Let us - consider the following "users" table that contains two columns named "username" and "email", - where "username" is also the primary key. + consider the following "users" table that contains two columns named "username" and "email", + where "username" is also the primary key. <com:TTextHighlighter Language="sql" CssClass="source"> CREATE TABLE users ( - username VARCHAR( 20 ) NOT NULL , - email VARCHAR( 200 ) , - PRIMARY KEY ( username ) + username VARCHAR( 20 ) NOT NULL , + email VARCHAR( 200 ) , + PRIMARY KEY ( username ) ); </com:TTextHighlighter> </p> <p>Next we define our plain <tt>User</tt> class as follows. Notice that - the <tt>User</tt> is very simple. + the <tt>User</tt> is very simple. <com:TTextHighlighter Language="php" CssClass="source"> class User { - public $username; - public $email; + public $username; + public $email; } </com:TTextHighlighter> </p> </p> <p>Next, we need to define a SqlMap XMl configuration file, lets name - the file as <tt>my-sqlmap.xml</tt> + the file as <tt>my-sqlmap.xml</tt> <com:TTextHighlighter Language="xml" CssClass="source"> <?xml version="1.0" encoding="utf-8" ?> <sqlMapConfig> @@ -174,10 +174,10 @@ class User </com:TTextHighlighter> </p> <p>The <select> tag returns defines an SQL statement. The <tt>id</tt> - attribute will be used as the identifier for the query. The <tt>resultClass</tt> - attribute value is the name of the class the the objects to be returned. - We can now query the objects as follows: - + attribute will be used as the identifier for the query. The <tt>resultClass</tt> + attribute value is the name of the class the the objects to be returned. + We can now query the objects as follows: + <com:TTextHighlighter Language="php" CssClass="source"> //assume that $sqlmap is an TSqlMapGateway instance $userList = $sqlmap->queryForList("SelectUsers"); @@ -188,49 +188,49 @@ $user = $sqlmap->queryForObject("SelectUsers"); </p> <p>The above example shows demonstrates only a fraction of the capabilities - of the SqlMap Data Mapper. Further details can be found in the - <a href="http://www.pradosoft.com/demo/sqlamp/">SqlMap Manual</a>. + of the SqlMap Data Mapper. Further details can be found in the + <a href="http://www.pradosoft.com/demo/sqlamp/">SqlMap Manual</a>. </p> <h2>Combining SqlMap with Active Records</h2> <p>The above example may seem trival and it also seems that there is - alot work just to retrieve some data. However, notice that the <tt>User</tt> - class is totally unware of been stored in the database, and the database is - unware of the <tt>User</tt> class. + alot work just to retrieve some data. However, notice that the <tt>User</tt> + class is totally unware of been stored in the database, and the database is + unware of the <tt>User</tt> class. </p> <p> - One of advantages of SqlMap is the - ability to map complex object relationship, collections from an existing - database. On the other hand, <a href="?page=Database.ActiveRecord">Active Record</a> - provide a very simple way - to interact with the underlying database but unable to do more complicated - relationship or collections. A good compromise is to use SqlMap to retrieve - complicated relationships and collections as Active Record objects and then using - these Active Records to do the updates, inserts and deletes. + One of advantages of SqlMap is the + ability to map complex object relationship, collections from an existing + database. On the other hand, <a href="?page=Database.ActiveRecord">Active Record</a> + provide a very simple way + to interact with the underlying database but unable to do more complicated + relationship or collections. A good compromise is to use SqlMap to retrieve + complicated relationships and collections as Active Record objects and then using + these Active Records to do the updates, inserts and deletes. </p> <p>Continuing with the previous example, we change the definition of the - <tt>User</tt> class to become an Active Record. + <tt>User</tt> class to become an Active Record. <com:TTextHighlighter Language="php" CssClass="source"> class UserRecord extends TActiveRecord { - public $username; //the column named "username" in the "users" table - public $email; - - private static $_tablename='users'; //table name - - /** - * @return TActiveRecord active record finder instance - */ - public static function finder() - { - return self::getRecordFinder('UserRecord'); - } + public $username; //the column named "username" in the "users" table + public $email; + + private static $_tablename='users'; //table name + + /** + * @return TActiveRecord active record finder instance + */ + public static function finder() + { + return self::getRecordFinder('UserRecord'); + } } </com:TTextHighlighter> </p> <p>We also need to change the definition of the SqlMap XML configuration. We - just need to change the value of <tt>resultClass</tt> attribute to <tt>UserRecord</tt>. + just need to change the value of <tt>resultClass</tt> attribute to <tt>UserRecord</tt>. <com:TTextHighlighter Language="xml" CssClass="source"> <?xml version="1.0" encoding="utf-8" ?> <sqlMapConfig> @@ -243,8 +243,8 @@ class UserRecord extends TActiveRecord <p>The PHP code for retrieving the users remains the same, but SqlMap - returns Active Records instead, and we can take advantage of the Active Record methods. - + returns Active Records instead, and we can take advantage of the Active Record methods. + <com:TTextHighlighter Language="php" CssClass="source"> //assume that $sqlmap is an TSqlMapGateway instance $user = $sqlmap->queryForObject("SelectUsers"); @@ -256,10 +256,10 @@ $user->save(); //save it using Active Record <h2>References</h2> <ul> - <li>Fowler et. al. <i>Patterns of Enterprise Application Architecture</i>, - Addison Wesley, 2002.</li> - <li>xxxx. <i>iBatis Data Mapper</i>, - <a href="http://www.apache.org/ibatis">http://www.apache.org/ibatis</a>.</li> + <li>Fowler et. al. <i>Patterns of Enterprise Application Architecture</i>, + Addison Wesley, 2002.</li> + <li>xxxx. <i>iBatis Data Mapper</i>, + <a href="http://www.apache.org/ibatis">http://www.apache.org/ibatis</a>.</li> </ul> </com:TContent>
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