From c004bbdf4f0e824e5ccbaef8f98ca4a3d44d3b49 Mon Sep 17 00:00:00 2001 From: wei <> Date: Fri, 14 Jul 2006 06:46:31 +0000 Subject: Changed SQLMap manual into a prado app. --- .../protected/pages/Manual/BigPicture.page | 151 +++++++++++++++++++++ 1 file changed, 151 insertions(+) create mode 100644 demos/sqlmap-docs/protected/pages/Manual/BigPicture.page (limited to 'demos/sqlmap-docs/protected/pages/Manual/BigPicture.page') diff --git a/demos/sqlmap-docs/protected/pages/Manual/BigPicture.page b/demos/sqlmap-docs/protected/pages/Manual/BigPicture.page new file mode 100644 index 00000000..7857d6ec --- /dev/null +++ b/demos/sqlmap-docs/protected/pages/Manual/BigPicture.page @@ -0,0 +1,151 @@ + +

The Big Picture

+

SQLMap is a simple but complete framework that makes it easy for you to map +your objects to your SQL statements or stored procedures. The goal of the +SQLMap framework is to obtain 80% of data access functionality using only +20% of the code.

+ +

What does it do?

+

Developers often create maps between objects within an application. One +definition of a Mapper is an "object that sets up communication between two +independent objects." A Data Mapper is a "layer of mappers that moves data +between objects and a database while keeping them independent of each other +and the mapper itself." [Patterns of Enterprise Architecture, ISBN +0-321-12742-0].

+ +

You provide the database and the objects; SQLMap provides the mapping layer +that goes between the two.

+ +

How does it work?

+ +

Your programming platform already provides a capable library for accessing +databases, whether through SQL statements or stored procedures. But developers +find several things are still hard to do well when using "stock" PHP +function including:

+ +

Separating SQL code from programming code Passing input parameters to the +library classes and extracting the output Separating data access classes from +business logic classes Caching often-used data until it changes Managing +transactions and many more -- by using XML documents to create a mapping +between a plain-old object and a SQL statement or a stored procedure. The +"plain-old object" can be any PHP object.

+ +

Tip: +The object does not need to be part of a special object hierarchy or implement +a special interface. (Which is why we call them "plain-old" objects.) +Whatever you are already using should work just fine. +

+ + alt="SQLMap DataMapper work flow" id="fig:diagram.png" class="figure"/> +
Figure 1: SQLMap DataMapper work flow
+ +

Here's a high level description of the work flow shown in the figure above: +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.

+ +

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.

+ +

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 type.

+ +

So, what does all this look like in your source code? Here's how you might +code the insert of a "lineItem" object into your database.

+ + +TMapper::instance()->insert("InsertLineItem", $lineItem); + + +

If your database is generating the primary keys, the generated key can be +returned from the same method call, like this:

+ + +$myKey = TMapper::instance()->insert("InsertLineItem", $lineItem); + + +

The following example shows an XML descriptor for "InsertLineItem". + + + INSERT INTO [LinesItem] + (Order_Id, LineItem_LineNum, Item_Id, LineItem_Quantity, LineItem_UnitPrice) + VALUES + (#Order.Id#, #LineNumber#, #Item.Id#, #Quantity#, #Item.ListPrice#) + + select @@IDENTITY as value + + + +

+ +

The <selectKey> stanza returns an auto-generated key from a SQL Server +database (for example). If you need to select multiple rows, SQLMap can return +a list of objects, each mapped to a row in the result set: + +$productList = Mapper::instance()->queryForList("selectProduct",$categoryKey); + +Or just one, if that's all you need: + +$product = Mapper::instance()->queryForObject("selectProduct",$categoryKey); + +

+ +

Of course, there's more, but this is SQLMap from 10,000 meters. (For a longer, +gentler introduction, see the Tutorial.) +The Data Map definition files describes +where the statement for "InsertLineItem" would +be defined. The Installation and Setup section describes +the "bootstrap" configuration file that exposes SQLMap to your application.

+ +

Is SQLMap the best choice for my project?

+

SQLMap is a Data Mapping tool. Its role is to map the columns of a database +query (including a stored procedure) to the properties of an object. If your +application is based on business objects (including array or lists of +objects), then SQLMap can be a good choice. SQLMap is an even better choice +when your application is layered, so that that the business layer is distinct +from the user-interface layer.

+ +

Under these circumstances, another good choice would be an Object/Relational +Mapping tool (OR/M tool), like [...]. Other products in this category are +[...] and [...] . An OR/M tool generates all or most of the SQL for you, +either beforehand or at runtime. These products are called OR/M tools because +they try to map an object graph to a relational schema.

+ +

SQLMap is not an OR/M tool. SQLMap helps you map objects to stored procedures +or SQL statements. The underlying schema is irrelevant. An OR/M tool is great +if you can map your objects to tables. But they are not so great if your +objects are stored as a relational view rather than as a table. If you can +write a statement or procedure that exposes the columns for your object, +regardless of how they are stored, SQLMap can do the rest.

+ +

So, how do you decide whether to OR/M or to DataMap? As always, the best +advice is to implement a representative part of your project using either +approach, and then decide. But, in general, OR/M is a good thing when you +

+Likewise, the best time to use a Data Mapper, like SQLMap, is when: + +

+ +

In the end, you have to decide what's best for your project. If a OR/M tool +works better for you, that's great! If your next project has different needs, +then we hope you give SQLMap another look. If SQLMap works for you now: +Excellent!

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