Jsp, Tomcat, J2Ee, Linux Web Hosting, Hibernate Programming Blog

CHAPTER 24 INTRODUCING POSTGRESQL popular systems like FreeBSD and Red Hat Linux, to obscure platforms like QNX and BeOS, and even to some major gaming platforms such as Sony PlayStation 2 and the Nintendo GameCube. Even with all of this flexibility, PostgreSQL often received knocks in the past because it required the Linux-like environment toolset Cygwin (http://cygwin.com) to run on Windows. PostgreSQL 8.0.0 silenced this critique by including full native Windows support on all recent versions of Windows (Windows XP, Windows NT, Windows 2000/2003). This new Windows port has been extremely popular, accounting for 65 percent of all downloads in the first few months of the 8.0.0 release, and should help to open up PostgreSQL to a whole new world of developers and users. Flexible Security Options PostgreSQL supports a wide array of security protocols and configuration options as well as features inside the database to help give you control over who and what may access the data inside your database. PostgreSQL security can be broken down into two major categories: Standards-based authentication methods, such as Kerberos, Pluggable Authentication Module (PAM), ident, and MD5 encryption, can be used to control client access to the database. This can be configured per user, per database, per connecting machine, or some combination of these, as needed for your environment. You can even require that connections be made over Secure Sockets Layer (SSL). Internal privileges, using standard SQL commands such as GRANT and REVOKE, allow for fine-grained control of objects inside the database. Users can be created with access to all tables, to only a few tables, or to only tables with read access. Combined with advanced features (e.g., functions, schemas, and views), you can even arrange for two different users to see completely different presentations of the same database. Given the importance of securing both your database and your data, we ll cover even more options and techniques as we look at different aspects of PostgreSQL, and we dedicate the whole of Chapter 29 to PostgreSQL security. Global Development, Local Flavor The group of developers that works on PostgreSQL is commonly referred to as the PostgreSQL Global Development Group. This moniker is quite fitting because, unlike many corporatecontrolled open-source databases whose direction is set at some company headquarters, PostgreSQL really is the product of hundreds of developers around the world. Because of this world-spanning contribution, PostgreSQL has extensive support for internationalization and localization. PostgreSQL has been translated into more than 20 languages, supports a wide variety of database encoding (including full Unicode support), and supports a wide variety of locales to help control collation order and number ordering. As with most aspects of PostgreSQL, you can also define your own locale for the database if you have a really specific need. Hassle-Free Licensing PostgreSQL is licensed under a BSD license, which means that it can be used in both opensource and commercial applications free of charge. This also makes PostgreSQL immune to
If you are in need for chaep and reliable webhost to host your website, our recommendation is http web server services.

574 CHAPTER 24 INTRODUCING POSTGRESQL PostgreSQL s Key Features PostgreSQL abounds with features of central importance to both personal programming projects and Fortune 500 operations alike. This section highlights many of those key attributes. Data Integrity The PostgreSQL developers have always striven to put data integrity at the top of their list. If a new feature would compromise data integrity, that feature is not allowed in until it can be made to work correctly and preserve data integrity. The same is true of performance improvements and other optimizations. Any database can be fast, but if you cannot trust it with your data, then what is the point? The philosophy of the PostgreSQL developers is to make it right, and then make it fast. Highly Scalable In most classic database systems, the management of concurrent transactions is done through a series of different locking mechanisms. Many of these systems are very fast at read-only queries or with a limited number of users, but begin to bog down once they are confronted by a large number of users reading and writing simultaneously. PostgreSQL avoids this problem by using a system known as Multiversion Concurrency Control (MVCC), in which each transaction sees only a snapshot of the data it is working with, isolating it from underlying data changes of other users. Feature-Complete While no software is ever done, PostgreSQL has supported basic database objects such as constraints, foreign keys, triggers, and views for years. It also supports a number of not-socommon features, including custom aggregates, domains, custom operators, and rules. Subquery support in PostgreSQL is top-notch, allowing for subqueries in the SELECT, FROM, and WHERE clauses of a query. On top of that, PostgreSQL also supports more than a dozen different server-side function languages, including C, SQL, PL/pgSQL, PL/Perl, PL/PHP, PL/Tcl, and PL/Ruby. This feature completeness has allowed PostgreSQL to start adding extremely high-end features, including point-in-time recovery (PITR), savepoints (nested transactions), and tablespaces. No matter what you are trying to do, PostgreSQL likely has a way to do it, and if it does not, you can probably add the new functionality yourself. Extensible Beyond just giving you source code access, PostgreSQL makes adding your own extensions to the database far easier by providing tools like custom aggregates, data types, domains, and operators. Full-text indexing, fuzzy string matching, OpenGIS, and trigram matching are just a few of the many packages that have been built on top of PostgreSQL. Platform Support PostgreSQL has always taken strides to be as functional as possible across different platforms. It has been ported to more than a dozen different Unix- and Linux-based platforms, from
Go visit our java server pages services for a reliable, lowcost webhost to satisfy all your needs.

CHAPTER 24 Introducing PostgreSQL In 1986, University of California at Berkeley professor and noted database technology expert Michael Stonebraker set out to build a better database system. Despite having already enjoyed a great deal of success with his previous database project, INGRES, Stonebraker decided that the code in INGRES had become sufficiently cumbersome that, rather than attempt to implement his new vision in the INGRES project, he should build a new system from the ground up, the result of which was what he dubbed POSTGRES. Over the next eight years, POSTGRES grew in popularity, particularly among the research community. Eventually this popularity became overwhelming, taking time away from the POSTGRES researchers, who should have been doing further database research. Thus, the POSTGRES project was officially ended at version 4.2. However, thanks to its release under the BSD license, this was not the end of the database project. Development was picked up by a handful of folks on the Internet, and in 1994, Andrew Yu and Jolly Chen added a SQL parser (replacing the previous QUEL language system) and subsequently released it as Postgres95. By 1996, it became obvious that the name Postgres95 didn t exactly imply a futuristic vision, so the database was released as PostgreSQL 6.0 by the developer community. The name PostgreSQL paid homage to the original POSTGRES project while also reflecting the new SQL capabilities that had been implemented, and the version number was set in line with the original POSTGRES project version line. Today PostgreSQL is one of the most popular open-source projects on the Internet. Like many of the projects that have come out of Berkeley (BIND, BSD Unix, sendmail, and Tcl rank among its contributions), PostgreSQL powers countless applications, Web sites, and even parts of the Internet backbone itself. In fact, some of the biggest and most popular organizations in the world use PostgreSQL on a regular basis, including the likes of Afilias Ltd. (the .info registrar), Apple Computers, BASF, Cisco Systems, and The World Health Organization (WHO). Even more important is the number of companies that provide project development and support resources, including the likes of Fujitsu, Pervasive Software Inc., Red Hat Inc., and SRA International Inc. It is worth noting that, while all of these companies are involved in PostgreSQL, none of them has any ownership of the code or control the direction of PostgreSQL development. All of that is run by volunteers within the community, and the developers collectively control what is added into the core system. Given this community-first approach to the project, what do all of these companies see in PostgreSQL? And more importantly, why should PostgreSQL be at the top of your list when you start a new database-backed project?
We recommend high quality webhost to host and run your jsp application: christian web host services.

572 CHAPTER 23 INTRODUCING PDO Summary PDO offers users a powerful means for consolidating otherwise incongruous database commands, allowing for an almost trivial means for migrating an application from one database solution to another. Furthermore, it encourages greater productivity among the PHP language developers due to the separation of language-specific and database-specific features. If your clients expect an application that allows them to use a preferred database, you re encouraged to keep an eye on this new extension as it matures in the coming months. The next chapter begins the detailed introduction to the PostgreSQL database server. From there you ll learn all about PostgreSQL installation and configuration, table structures, datatypes, and a variety of other pertinent topics. This sets the stage for several chapters discussing how PHP and PostgreSQL are most effectively integrated.
Please visit Domain Name Hosting services for high quality webhost to host and run your jsp applications.

CHAPTER 23 INTRODUCING PDO // Create and prepare the query $query = “SELECT sku, name FROM product WHERE rowID=1″; $stmt = $dbh->prepare($query); $stmt = $dbh->execute(); // Bind according to column offset $stmt->bindColumn(1, $sku); // Bind according to column name $stmt->bindColumn(’name’, $name); // Output the data echo “Product: $name ($sku)”; This returns the following: Painless Aftershave (ZP457321) Transactions PDO offers transaction support for those databases capable of executing them. Three PDO methods facilitate transactional tasks, beginTransaction(), commit(), and rollback(). Because Chapter 36 is devoted to a complete introduction to transactions, no examples are offered here; instead, brief introductions to these three methods are offered. beginTransaction() boolean PDO::beginTransaction() The beginTransaction() method disables autocommit mode, meaning that any database changes will not take effect until the commit() method is executed. Once either commit() or rollback() is executed, autocommit mode will automatically again be enabled. commit() boolean PDO::commit() The commit() method commits the transaction. rollback() boolean PDO::rollback() The rollback() method negates any database changes made since beginTransaction() was executed.
Go visit our java server pages services for a reliable, lowcost webhost to satisfy all your needs.

570 CHAPTER 23 INTRODUCING PDO The resulting output follows. Note that the product name and SKU don t correspond to the correct values as provided in the sample data table. Product: AquaSmooth Toothpaste (PO988932) setFetchMode() boolean PDOStatement::setFetchMode (int mode) If your script requires that fetch() or fetchAll() be used several times, and you plan on using a fetching setting other than the default PDO_FETCH_BOTH, you can save some typing by declaring a new default setting at the top of the script using setFetchMode(). Just set the mode parameter to the appropriate setting (see the previous introduction to fetch() for a list of available settings), and all subsequent calls to fetch() or fetchAll() will produce result sets capable of being referenced accordingly. Setting Bound Columns In the previous section you learned how to set the fetch_style parameter in the fetch() and fetchAll()methods to control how the resultset columns will be made available to your script. You were probably intrigued by the PDO_FETCH_BOUND setting, because it seems to enable you to avoid an additional step altogether when retrieving column values, and instead just assign them automatically to predefined variables. Indeed this is the case, and it s accomplished using the bindColumn() method, introduced next. bindColumn() boolean PDOStatement::bindColumn (mixed column, mixed &param [, int type [, int maxlen [, mixed driver_options]]]) The bindColumn() method is used to match a column name to a desired variable name, which, upon each row retrieval, will result in the corresponding column value being automatically assigned to the variable. The column parameter specifies the column offset in the row, whereas the &param parameter defines the name of the corresponding variable. You can set constraints on the variable value by defining its type using the type parameter, and limiting its length using the maxlen parameter. Six type parameter values are supported. See the earlier introduction to bindParam() for a complete listing. The following example selects the sku and name columns from the product table where rowIDequals 1, and binds the results according to a numerical offset and associative mapping, respectively: // Connect to the database server $dbh = new PDO(”pgsql:host=localhost;dbname=corporate”, “websiteuser”, “secret”);
Searching for affordable and proven webhost to host and run your servlet applications? Go to Linux Web Hosting services and you will find it.

CHAPTER 23 INTRODUCING PDO // Retrieve all of the rows $rows = $result->fetchAll(); // Output the rows foreach ($rows as $row) { $sku = $row[’sku’]; $name = $row[’name’]; echo “Product: $name ($sku)
“; } Sample output follows: Product: AquaSmooth Toothpaste (TY232278) Product: HeadsFree Shampoo (PO988932) Product: Painless Aftershave (ZP457321) Product: WhiskerWrecker Razors (KL334899) As to whether you choose to use fetchAll() over fetch(), it seems largely a matter of convenience. However, keep in mind that using fetchAll() in conjunction with particularly large result sets could place a large burden on the system, both in terms of database server resources and network bandwidth. fetchColumn() string PDOStatement::fetchColumn ([int column_number]) The fetchColumn() method returns a single column value located in the next row of the result set. The column reference, assigned to column_number, must be specified according to its numerical offset in the row, which begins at zero. If no value is set, fetchColumn() returns the value found in the first column. Oddly enough, it s impossible to retrieve more than one column in the same row using this method, as each call will move the row pointer to the next position; therefore, consider using fetch() should you need to do so. The following example both demonstrates fetchColumn() and shows how subsequent calls to the method will move the row pointer: // Execute the query $query = “SELECT sku, name FROM product ORDER BY name”; $result = $dbh->query($query); // Fetch the first row first column $sku = $result->fetchColumn(); // Fetch the second row second column $name = $result->fetchColumn(1); // Output the data. echo “Product: $name ($sku)”;
If you are searching for cheap webhost for your web application, please visit MySQL5 Web Hosting services.

568 CHAPTER 23 INTRODUCING PDO PDO_FETCH_LAZY: Creates associative and indexed arrays, in addition to an object containing the column properties, allowing you to use whichever of the three interfaces you choose. PDO_FETCH_OBJ: Causes fetch() to create an object consisting of properties matching each of the retrieved column names. PDO_FETCH_NUM: Causes fetch() to retrieve an array of values indexed by the numerical offset of the column in the row (beginning with 0). The cursor_orientation parameter determines which row will be retrieved should the object be a scrollable cursor. The cursor_offset parameter is an integer value representing the offset of the row to be retrieved relative to the present cursor position. The following example retrieves all of the products from the database, ordering the results by name: // Execute the query $query = $dbh->prepare(”SELECT sku, name FROM product ORDER BY name”); $query->execute(); while ($dbh->fetch(PDO_FETCH_ASSOC) as $row) { $sku = $row[’sku’]; $name = $row[’name’]; echo “Product: $name ($sku)
“; } Sample output follows: Product: AquaSmooth Toothpaste (TY232278) Product: HeadsFree Shampoo (PO988932) Product: Painless Aftershave (ZP457321) Product: WhiskerWrecker Razors (KL334899) fetchAll() array PDOStatement::fetchAll ([int fetch_style]) The fetchAll() method works in a fashion quite similar to fetch(), except that a single call to it will result in all rows in the result set being retrieved and assigned to the returned array. The way in which the retrieved columns are referenced depends upon how the optional fetch_style parameter is set, which by default is set to PDO_FETCH_BOTH. See the preceding section regarding the fetch() method for a complete listing of all available fetch_style values. The following example produces the same result as the example provided in the fetch() introduction, but this time depends on fetchAll() to ready the data for output: // Execute the query $query = “SELECT sku, name FROM product ORDER BY name”; $result = $dbh->query($query);
Please visit Domain Name Hosting services for high quality webhost to host and run your jsp applications.

CHAPTER 23 INTRODUCING PDO Retrieving Data PDO s data-retrieval methodology is quite similar to that found in any of the other database extensions. In fact, if you ve used any of these extensions in the past, you ll be quite comfortable with PDO s five relevant methods. These methods are introduced in this section, and are accompanied by examples where practical. All of the methods introduced in this section are part of the PDOStatement class, which is returned by several of the methods introduced in the previous section. columnCount() integer PDOStatement::columnCount() The columnCount() method returns the total number of columns returned in the result set. An example follows: // Execute the query $query = “SELECT sku, name FROM product ORDER BY name”; $result = $dbh->query($query); // Report how many columns were returned echo “There were “.$result->columnCount().” product fields returned.”; Sample output follows: There were 2 product fields returned. fetch() mixed PDOStatement::fetch ([int fetch_style [, int cursor_orientation [, int cursor_offset]]]) The fetch() method returns the next row from the result set, or FALSE if the end of the result set has been reached. The way in which each column in the row is referenced depends upon how the fetch_style parameter is set. Six settings are available, including: PDO_FETCH_ASSOC: Causes fetch() to retrieve an array of values indexed by the column name. PDO_FETCH_BOTH: Causes fetch() to retrieve an array of values indexed by both the column name and the numerical offset of the column in the row (beginning with 0). This is the default. PDO_FETCH_BOUND: Causes fetch() to return TRUE and instead assign the retrieved column values to the corresponding variables as specified in the bindParam() method. See the later section Setting Bound Columns for more information about bound columns.
If you are in need for chaep and reliable webhost to host your website, our recommendation is http web server services.

566 CHAPTER 23 INTRODUCING PDO PDO_PARAM_LOB: SQL large object datatype PDO_PARAM_STMT: PDOStatement object type; presently not operational PDO_PARAM_INPUT_OUTPUT: Used when the parameter is passed into a stored procedure and therefore could be changed after the procedure executes The length parameter specifies the datatype s length. It s only required when assigning it the PDO_PARAM_INPUT_OUTPUT datatype. Finally, the driver_options parameter is used to pass along any database driver specific options. Let s revisit the previous example, this time using bindParam()to assign the column values: // Connect to the database server $dbh = new PDO(”pgsql:host=localhost;dbname=corporate”, “websiteuser”, “secret”); // Create and prepare the query $query = “INSERT INTO product SET sku = :sku, name = :name”; $stmt = $dbh->prepare($query); $sku = ‘MN873213′; $name = ‘Minty Mouthwash’; // Bind the parameters $stmt->bindParam(’:sku’, $sku); $stmt->bindParam(’:name’, $name); // Execute the query $stmt->execute(); // Bind the parameters $stmt->bindParam(’:sku’, ‘AB223234′); $stmt->bindParam(’:name’, ‘Lovable Lipstick’); // Execute again $stmt->execute(); If question mark parameters were used, the statement would look like this: $query = “INSERT INTO product SET sku = ?, name = ?”; Therefore, the corresponding bindParam() calls would look like this: $stmt->bindParam(1, ‘MN873213′); $stmt->bindParam(2, ‘Minty Mouthwash’); . . . $stmt->bindParam(1, ‘AB223234′); $stmt->bindParam(2, ‘Lovable Lipstick’);
Please visit Domain Name Hosting services for high quality webhost to host and run your jsp applications.