shannon 2002/06/07 14:13:35
Modified: src/documentation/xdocs/userdocs/concepts databases.xml
Log:
Sorry, this is the proper
revised file.
Revision Changes Path
1.3 +57 -52
xml-cocoon2/src/documentation/xdocs/userdocs/concepts/databases.xml
Index: databases.xml
===================================================================
RCS file:
/home/cvs/xml-cocoon2/src/documentation/xdocs/userdocs/concepts/databases.xml,v
retrieving revision 1.2
retrieving revision 1.3
diff -u -r1.2 -r1.3
--- databases.xml 7 Jun 2002 21:10:52 -0000 1.2
+++ databases.xml 7 Jun 2002 21:13:35 -0000 1.3
@@ -14,9 +14,9 @@
<s1 title="Introduction">
<p>
- Publishing dynamic content or creating web-applications at
- some point often involves database access. Apache Cocoon
- offers a number of different facilities to access
+ Publishing dynamic content or creating web-applications
+ eventually involves adatabase access. Apache Cocoon
+ offers a number of different approaches to access
(object) relational and XML databases. This document provides
an overview of the different ways to access (object)
relational databases.
@@ -30,39 +30,39 @@
Basically, there are three different approaches available:
<link href="actions.html">Actions,</link> <link
href="../xsp/logicsheet-concepts.html">logicsheets,</link>
- and <link href="sitemap.html">transformers.</link> Each has
- its merits and difficulties.
+ and <link href="sitemap.html">transformers.</link> Each approach has
+ its pros and cons.
</p>
</s1>
- <s1 title="Actions">
+ <s1 title="Actions Approach">
<p>
<link href="actions.html">Actions</link> are code to be executed
- during pipeline setup. The outcome of an action can change how the
pipeline is
- assembled. For exampl, a pipeline may produce an alternative
- page to display when a database operation failed.
+ during pipeline setup. The outcome of an action can change how a
pipeline is
+ assembled. For example, a pipeline may produce an alternative
+ page to display upon failure of a particular database operation.
</p>
<p>
Actions are especially great for inserting, changing, or deleting
data.
- When pipeline switching features of actions are used, pages can be
simpler
- as they are only concerned with one view - either successful operation
- or failure.
+ Employing the pipeline-switching features of actions will simplify
your
+ pages. Such actions are concerned with only one view: either the
success
+ or failure of an operation.
</p>
<p>
- Even for data that is not user-provided, actions can be useful.
- Tracking information can be stored in a database from a central
- location without the need to modify every page.
+ Actions can be useful, even when data is not provided by users.
+ For example, you could store tracking information in a database in
+ a central location without the need to modify every page.
</p>
<p>
- Database actions allow also to read data from a database. This is
- useful if the pipeline assembling depends on this data or to setup an
- environment for processing on a XSP.
+ Database actions can read and return data from a database. This is
+ useful when the pipeline assembly depends upon such data. It's also
+ useful when setting up an environment for XSP processing.
</p>
<p>
- A big advantage of these actions is, that once the database meta data
- is captured into a descriptor file in XML, using any of these actions
- is just a matter of placing it in the pipeline, no programming is
- required, not even writing SQL queries.
+ Once the database meta data is captured in an XML descriptor file,
+ making use of these actions is simply a matter of placing them in a
pipeline.
+ This is a major advantage of the action approach. No programming is
+ required, not even SQL query writing.
</p>
<p>
A detailed description can be found <link
@@ -70,27 +70,30 @@
</p>
</s1>
- <s1 title="ESQL Logicsheet">
+ <s1 title="ESQL Logicsheet Approach">
<p>
- Usage of logicsheets is limited to XSPs, ESQL is currently available
- for JAVA XSPs. In addition, the interface is largely modelled after
- JDBC, and it is advantageous to be familiar with it.
- </p>
- <p>
- ESQL is great to read data from a database while it is less attractive
- to react to operation failures because that makes the XSP complex and
- less easy to understand and maintain.
- </p>
- <p>
- Complex layouts of the data read are easy to achieve. ESQL allows
- arbitrary nesting of queries and connections, provides support for
- stored procedures and complex data types. For generating reports that
- can be used with other XML-aware software or formated with XSL or CSS2,
- ESQL provides means to create a structured representation of the
- database data with just one tag. XML data can be retrieved from the
- database and included in the output, ESQL supports skipping part of the
- resultset and limiting the result with some supported database
- management systems. With the full power of JAVA available on the XSP,
+ The use of logicsheets is limited to XSPs. ESQL is currently available
+ for JAVA XSPs. Its interface is modeled largely on
+ JDBC. Thus, it is advantageous to be familiar with JDBC.
+ </p>
+ <p>
+ ESQL is great when reading data from a database. However, it is less
attractive
+ to use when it has to react to operation failures. This is due to the
fact
+ that it adds a layer of complexity to an XSP file, making it
+ more difficult to understand and maintain.
+ </p>
+ <p>
+ Complex layouts of the data are easy to achieve. ESQL allows
+ the arbitrary nesting of queries and connections. It also provides
support for
+ stored procedures and complex data types. ESQL provides a means to
+ create a structured representation of the database data with a single
tag.
+ This is useful when generating reports to use
+ with other XML-aware software or to be formated with XSL or CSS2.
+ XML data can be retrieved from the
+ database and included in the output. With some supported database
+ management systems, ESQL supports skipping part of the
+ resultset as well as limiting the result.
+ Given the full power of Java available within XSP,
any processing of the data is possible.
</p>
<p>
@@ -99,20 +102,22 @@
</p>
</s1>
- <s1 title="SQL Transformer">
+ <s1 title="SQL Transformer Approach">
<p>
- As a transformer, this approach can be combined with any kind
- of page. This results in slightly cleaner pages as some of the
- setup ESQL requires is not needed.
+ An approach using the SQL transformer can be combined with any kind
+ of page. This will result in slightly cleaner pages as you don't need
+ some of the setup that an ESQL approach requires.
</p>
<p>
- On the other hand it is more or less impossible to react to operation
- failures since the pipeline is already assembled and logic is not
- available inside transformers unless a custom transformer is written.
- This makes the transformer approach best for retrieving data. Creating
- an XML representation of the query result is even simpler than with
+ On the other hand, it is more or less impossible to react to operation
+ failures. This is due to the fact that the pipeline is already
assembled
+ and the necessary logic to handle such failures is not
+ available inside the SQL transformer, unless of course, you are willing
+ to write a custom transformer.
+ Thus, the transformer approach is best for retrieving data. Creating
+ an XML representation of the query result is even simpler than when
using the ESQL logicsheet. The transformer supports stored procedures.
- No programming is required apart from writing SQL.
+ No programming is required, apart from writing SQL.
</p>
<p>
A detailed description can be found <link
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