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Data migration projects - why and how

Data migration reasons Sooner or later, if you are a database developer or a data architect, you will be faced with a data migration project. Data migrations are executed by organizations due to many different factors. The organizations try to avoid the data migrations, if they can, because in many cases it is a costly and complicated process. Optimally, a data driven application should work for many years without major changes, aside from only patching and updating their data store. Indeed, even upgrading a database version to a newer one can become quite a complicated project, well exceeding the backup-restore approach, so desired by the management and the development teams. Here is a few of many reasons why the migrations take place....

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Enum data type in MySQL

While investigating features of MySQL database engine, I came across an interesting concept: the enum data type.   The enum data type allows for defining static data ranges that can be used as values of certain attributes. These ranges typically are quite small - for example marital status consists of 'Married', 'Single', 'Widowed', 'Divorced', 'N/A' . These five values can be encoded as an enum data type column. For example, we can define a table in the following way. create table Person ( FirstName varchar(50) not null, SurName varchar(50) not null, MaritalStatus enum ('Married', 'Single', 'Widowed', 'Divorced', 'N/A') not null ); Please note this is a very simplified code. Enum in MySQL has a certain feature - the values in rows...

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Activation of Cherry City Software OLEDB Provider for MySQL

If you read my previous post, How to install MySQL Connection Provider, you know that installation of the provider is just the first step. Yes, you can test the connection, but any attempt to run a query against your MySQL database will result with error saying "MySQL OLE DB provider has not been activated".  I was stuck for a while with this error - it doesn't direct exactly to a resolution of the issue. I analyzed the code of SelectCompare and found nothing wrong with it. I googled for some information pertaining to the error message. I found some old pages that referenced the message, but no solutions.  This made me thinking - after all, if Google doesn't show relevant results, there must...

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How to install MySQL Connection Provider

SelectCompare can connect to virtually any OleDB or ODBC data source. Once you have the connection provider installed, you can use SelectCompare to connect to respective database and compare its data with any other data set you wish. Data provider installation There is a number of different providers for MySQL. I used in this example one older, but still popular provider implemented by Cherry City Software. You can download the MySQL data provider from the download page. After you download the archive, extract its contents to a folder and run the setup. This is a pretty standard installation wizard. Follow the installation wizard until the installation is complete. You will have to have administrative rights on your machine to install...

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Write Select Statements for Excel Spreadsheets

You are reading this post because there is a chance you want to compare two spreadsheets in Excel, and you are looking for a way to do it easily and effectively. SelectCompare allows for data comparison of Excel spreadsheets, as well as other data sources with simple, unified interface. You can export your comparison to Excel for further analysis or sharing. You may be initially anxious about writing an SQL statement to pull data from your Excel, but unnecessarily. It is not that difficult! This post will show you a few examples of writing queries against your spreadsheet that you will be able to use right away for your Excel data comparison. If you want to find out how to connect...

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