Adapt Your CSV to Fit the Relational Model Here’s the SQL code for the PDM, which flows from the relational schema and is compatible with the SQLite3 RDBMS. So, here’s your adapted relational model after correcting the issues mentioned above and adding artificial keys: Latest version of the relational model However, don’t be surprised if you see the opposite happening in the work world, as good practices are rarely adopted. The PDM flows directly from the relational model (LDM).Īt the end of the chapter “Determine Your Primary Keys,” we discussed only using artificial keys in your LDM in specific cases, but you are encouraged to use them in all tables for the PDM. The PDM is highly dependent on the chosen RDBMS because each has its own variant of SQL and different features. Next, you need to develop the physical data model (PDM). To resolve the second point, remove the season attribute from the production table, meaning that you’ll lose this piece of information. ![]() It also means that the association between shooting_period and director will turn into a one-to-many relationship (instead of many-to-many). So, the name attribute in the director will no longer be atomic, which will violate the 1NF. To resolve the first point, allow director to hold a pair of directors in the same row. It’s a shame because it will impact the quality, but it will make it much simpler for you. Instead, we’re going to change the relational model. When this happens, you need to look at the filming date for each series, which would take too long. Either way, it's too tricky.įor series productions, the season number is often missing. You either need to check thousands of rows by hand and separate the pairs to resolve this or create a formula that will do it automatically. However, the director table can only have one director per row in your relational model. The Director column in your file is multivalued (i.e., some rows contain pairs of directors). Some data cleansing activities will be simple, while others are complex. So you first need to go through a process of data cleansing. You’ve created a high-quality relational model, so well done!īut the data you have available isn’t particularly high quality, and you're about to find out why. Adapt Your Relational Model and Create the PDM It would be mean (but true) to say at this point that all you've done is a couple of drawings your database doesn't exist yet! But thankfully, by the end of this chapter, you’ll have an actual database that you can query using SQL. You've worked hard to create your CDM and LDM. Is there any way to do this in Valentina Studio - e.g.We’re almost at the end of the course. SELECT extension6("d:\example path\filename.docx") I could then call this from a SQL query to output the results, or to update a table. If ( arguments.substring(arguments.lastIndexOf('\u005C')).lastIndexOf('.') = -1 )Įxt = arguments.substring(arguments.lastIndexOf('.') 1).trim() in SQLiteStudio I could define a Qtscript function called extension6 to return the file extension of a file (if it's fewer than six characters): However, there doesn't seem to be any way to call those scripts/function from an SQL query.Į.g. I can see that Valentina supports Javascript and that you can save scripts in the vsp project files. It's possible to build up quite complex logic in QtScript and so the integration with SQL, whether it's querying based on them or updating tables etc, is very powerful. ![]() (2) In SQLiteStudio, it's possible to define functions in QtScript, which then can be called from SQL statements. If necessary, I could live with running my projects in Valentina DB, if I can get (2) to work below. I know that Valentina DB itself has hashing functions, but I'd like to be able to use them within SQLite. I can see there is an option to "Show Extensions" in the Schema editor if you right click on the database name, with options to add/delete, but those buttons don't work and the sha1 library isn't listed. I can't see that the extension is loading at all. I've downloaded the dlls from here:, but if I try: However, I can't get the extensions to load in Valentina Studio. I know that SQLite doesn't support that natively, but there are extensions available that allow you to use that. (1) I need to be able to use hashing functions ( e.g. This is all running locally, rather than server based. ![]() I came across Valentina Studio, which looks fully featured, but I'm having trouble replicating functionality that I'm used to with SQLiteStudio, while still using my SQLite databases. I've been using SQLiteStudio for some years, but it doesn't seem to be maintained as much as it used to be so I'm looking for an alternative.
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