![]() With this blogpost I hope to have given you inspiration to build your own import structure of flat files in those cases where the structure might change.Īs seen above the approach needs some. The only boundaries are set by limits to your imagination It is also possible to auto generate missing columns in the destination table based on columns from the bulk table. Going from here, a suggestion could be to set up processes that compared the two tables (bulk and destination) and throws an error if X amount of the columns are not present in the bulk table or X amount of columns are new. Changing columns, column order and other changes, can be handled in an easy way with a few lines of code. This is to be handled by processed outside this demo.Īs this demo and post shows it is possible to handle dynamic changing flat source files. No errors will be thrown.įrom here there are some remarks to be taken into account:Īs no errors are thrown, the source files could be empty and the data updated could be blank in the destination table. The result is that the destination table is correct and loaded with the right data every time – and only with the data that corresponds with the source. The exact same thing would be able to be used with the other source files in this demo. The console application can also be called from TSQL like this: The content of the format file is as follows: The above script generates a format file in the directory c:\source\ and names it personlistFormatFile.xml. Generateformatfile.exe -p c:\source\ -f personlist.csv -o personlistformatfile.xml -d You are very welcome to contribute to the GitHub project in that case. Net developer, so someone might have another way of doing this. EXE files content and origin, you can download the code and build your own version of the GenerateFormatFile.exe application.Īnother note is that I’m not hard core. NET console application that solves just that. Generation of the initial format file for a curtain source is rather easy when setting up the import.īut what if the generation of the format file could be done automatically and the import process would be more streamlined and manageable – even if the structure of the source file changes?įrom my GitHub project you can download a home brewed. A format file is a simple XML file that contains information of the source files structure – including columns, datatypes, row terminator and collation. In section E of the example scripts from MSDN, it is described how to use a format file. This is using the OPENROWSET functionality from TSQL. There is another way to import flat files. When using the above BULK INSERT functionality from TSQL the import process often goes well, but the data is wrong with the source file is changed. If it was to be made with an integration tool like SQL Server Integration Services, the errors would be different and the SSIS package would throw more errors and not be able to execute the data transfer. The above examples are made with pure TSQL code. This file could be imported to a SQL Server database (in this example named FlatFileImport) with below script: This is quite understandable, as the process of data transportation from the source to the destination needs to know where to map every column from the source to the defined destination.Ī source flat file table like below needs to be imported to a SQL server database. ![]() When importing flat files to SQL server almost every standard integration tool (including TSQL bulkload) requires fixed metadata from the files in order to work with them. ![]() Even if the columns change order or existing columns are missing. When implemented, the process of importing flat files with changing metadata is handled in a structured, and most important, resiliant way. So I’ve come up with an alternative solution that I would like to share with you. Ever been as frustrated as I have when importing flat files to a SQL Server and the format suddenly changes in production?Ĭommonly used integration tools (like SSIS) are very dependent on the correct, consistent and same metadata when working with flat files.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |