Showing entries 24441 to 24450 of 44955
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Security Benefit By Switching to MYSQL

From a security standpoint VFP is a nightmare. You can do pretty much anything on the program end with passwords etc but I never found a way around the fact that you pretty much have to give the client access to the Data directory. VFP being a flat file system (even with the introduction of DBC’s – databases) you had to give the client at the very least read access to the tables and if you wanted him/her to change something then write access too. Only way around that might have been to use VFPOLEDB and a web server but then why use VFP.

Now moving to MYSQL I want to point out some instant benefits you get migrating to MYSQL and that is security. One thing probably not immediatly visible to a newbie is the power of the “DEFINER” and INVOKER security options on stored procedures. This allows clients to do things under certain circumstances that they do have no right to. I want to use the following example to demonstrate the very …

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Optimizing differences

I would like to use this installment of my blog to show some differences between VFP and MYSQL on how problems need to be solved. On the top it seems to me that the MYSQL optimizer needs a quite different strategy and some more help then the “rushmore” one in VFP. There is probably some room for improvements left in both approaches but I usually stop optimizing when I get under 2 seconds on getting results.

The task was to roll back the AR aging to a prior date. Basically a standard business problem. Accounting comes, looks at last months aging, makes some adjustments and then wants to rerun the aging, or the bank wants it as of a particular date or things just went nuts and everyone was busy with … whatevever …. and did not get to run the aging at the proper time. So to handle this a query was devised to back out all invoices and applications as to a certain date.

In the late 80’s the customer got and SBT accounting …

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Build MySQL Cluster 7.1 from source – including MySQL Cluster Connector for Java

If you want to try out the beta features in MySQL Cluster 7.1 then you can either use the appropriate binaries or you can build it for yourself from source. Here I explain how to do this on LINUX.

Note that if you want to make use of OpenJPA then you first need to install OpenJPA and Connector/J.

The example here was on Fedora12 with the MySQL Cluster 7.1.2 source:

CFLAGS=”-O3″ CXX=gcc CXXFLAGS=”-O3 -felide-constructors -fno-exceptions -fno-rtti” ./configure -prefix=/usr/local/mysql –enable-assembler –with-mysqld-ldflags=-all-static –with-plugins=max –with-openjpa …

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Four short links: 19 March 2010
  1. Tsung -- GPLed multi-protocol (HTTP, PostgreSQL, MySQL, WebDAV, SOAP, XMPP) load tester written in Erlang.
  2. Myth of China's Manufacturing Prowess -- The latest data shows [...] that the United States is still the largest manufacturer in the world. In 2008, U.S. manufacturing output was $1.8 trillion, compared to $1.4 trillion in China (UN data. China’s data do not separate manufacturing from mining and utilities. So the actual Chinese manufacturing number should be much smaller). Also contains pointers to an interesting discussion of lack of opportunities for college grads in China.
  3. OpenSSO and the Value of Open Source -- …
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Kontrollbase rev292 gets important UI layout fixes

This is a small revision and will only be available through SVN. However, it is an important one to speak about as it solves a former issue when running the application on a screen smaller than 1024px wide. While most users may not have noticed this since they have larger monitors it has been noticed [...]

Greatest N per group: top 3 with GROUP_CONCAT()

In my opinion, one of the best things that happened to Planet MySQL lately, is Explain Extended, a blog by Alex Bolenok (also known as Quassnoi on Stackoverflow).

I never had the pleasure of meeting Alex in person, but his articles are always interesting and of high quality, and the SQL wizardry he pulls off is downright inspiring. I really feel humbled by the creativity of some of his solutions and his apparent experience with multiple RDBMS products.

Alex' most recent post is about aggregation, and finding a top 3 based on the aggregate:

In …

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New feature for quick filters: Distinct values

As soon as you update to the latest build (Help > Check for updates), you will get a new menu item "More values" in the "Quick filter" menu. This new submenu displays the 30 first distinct values of the selected column, plus their frequency in the selected table:



Thanks to Daniel for suggesting this feature!

Generating unique integer IDs from strings in MySQL

I have an interesting problem, on a data migration project I'm currently working on. I'm importing a large amount of legacy data into Drupal, using the awesome Migrate module (and friends). Migrate is a great tool for the job, but one of its limitations is that it requires the legacy database tables to have non-composite integer primary keys. Unfortunately, most of the tables I'm working with have primary keys that are either composite (i.e. the key is a combination of two or more columns), or non-integer (i.e. strings), or both.

Table with composite primary key.

The simplest solution to this problem would be to add an auto-incrementing integer primary key column to the legacy tables. This would provide the primary key information that Migrate needs in order to do its mapping of legacy IDs to Drupal IDs. But this solution has a serious drawback. In my project, …

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Generating unique integer IDs from strings in MySQL

I have an interesting problem, on a data migration project I'm currently working on. I'm importing a large amount of legacy data into Drupal, using the awesome Migrate module (and friends). Migrate is a great tool for the job, but one of its limitations is that it requires the legacy database tables to have non-composite integer primary keys. Unfortunately, most of the tables I'm working with have primary keys that are either composite (i.e. the key is a combination of two or more columns), or non-integer (i.e. strings), or both.

Table with composite primary key.

The simplest solution to this problem would be to add an auto-incrementing integer primary key column to the legacy tables. This would provide the primary key information that Migrate needs in order to do its mapping of legacy IDs to Drupal IDs. But this solution has a serious drawback. In my project, …

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Greatest N per group: dealing with aggregates

Answering questions asked on the site.

Vlad Enache asks:

In MySQL I have a table called meanings with three columns:

person word meaning
1 1 4
1 2 19
1 2 7
1 3 5

word has 16 possible values, meaning has 26.

A person assigns one or more meanings to each word. In the sample above, person 1 assigned two meanings to word 2.

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