I am not very experienced developer in backend, and I am trying to build the simple CMS. I use go and gin framework, and database/sql package to interact with DB. So, the question is that sometimes I have to perform very similar queries, but they are slightly different.
For example, sometimes I want to add where clause dynamically, or simply omit it. Or I have to create new row or updating existing – despite different query, they basically perform similar operations. Or I want to add or clause.
So, I write a lot of duplicated code. What is the best way to avoid it?
Related
I have reviewed the previous Questions and haven't found the answer to the following question,
Is there a Database Tool available in MS Access to run and identify the Queries that are NOT Bring used as a part of my database. We have lots of Queries that are no longer used and I need to clean the database and get rid of these Queries.
Access does have a built in “dependency” feature. The result is a VERY nice tree-view of those dependencies, and you can even launch such objects using that treeview of your application to “navigate” the application so to speak.
The option is found under database tools and is appropriately called Object Dependencies.
The result looks like this:
While you don't want to use auto correct, this feature will force on track changes. If this is a large application, then on first run a significant delay will occur. After that, the results can be viewed instantly. So, most developers still turn off track name autocorrect (often referred to track auto destroy). However, the track auto correct is required for this feature.
And, unfortunately, you have to go query by query, but at least it will display dependences for each query - (forms, or reports). However, VBA code that creates SQL on the fly and uses such queries? Well, it will not catch that case. So, at the end of the day, deleting a query may well still be used in code, and if that code creates SQL on the fly (as at LOT of VBA code does, then you can never really be sure that the query is not not used some place in the application.
So, the dependency checker can easy determine if another query, another form/sub form, or report uses that query. So dependency checker does a rather nice job.
However, VBA code is a different matter, and how VBA code runs and does things cannot be determined until such time code is actually run. In effect, a dependency checker would have to actually run the VBA code, and even then, sometimes code will make several choices as to which query to run, or use - and that is determined by code. I suppose that you could do a quick "search", since a search is global for VBA (all code in modules, reports and forms can be searched). This would find most uses of the query, but not in all cases since as noted VBA code often can and does create sql on the fly.
I have a vague recollection part of Access Analyzer from FMS Inc has this functionality built in.
Failing that, I can see 2 options that may work.
Firstly, you could use the inbuilt Database Documenter. This creates a report that you can export to Excel. You would then need to import this into the database, and write some code that loops the queries to see if they appear in this table;
Alternatively, you could use the undocumented "SaveAsText" feature to loop all Forms/Reports/Macros/Modules in your database, as well as looping the Querydefs and saving their SQL into a text file. You would then write some VBA to loop the queries, open each of the text files and check for the existence of the query.
Either way, rather than just deleting any unused queries, rename then to something like "old_Query", and leave them for a month or so in the database just in case!!
Regards,
I would like to be able to run SQL queries in pages of a Mediawiki (inline queries). I am not even sure if this is possible or if we can do it only through SSH. I find information provided by MediaWiki pretty confusing for a new user.
As far as i am concerned, the SQL queries are wrapped for security reasons, so syntax will not be SQL exactly.
The questions would be:
Can we make inline SQL (or wrapped SQL) queries in Mediawiki pages? If yes, how? If not, is there a 'similar' alternative for it? (For example, creating a function with the query in it an accessing it). Please, provide examples if possible and take in account i am not familiar with Mediawiki data structure.
Let´s assume, for example, that i want to know all pages created by a users named 'user1' and 'user2'.
Also, if there is an extension which helps with this it would be worth mentioning.
I am using wampserver3.0.6_x64, apache2.4.23, mysql5.7.14 and php5.6.25.
After searching for a while, i tested 2 extensions which in conjuction can work very well for this task:
Cargo
And Page forms
Cargo allows you creating SQL tables which work independently from other MW content (meaning that you will have to introduce info in these tables using a wrapped SQL syntax, recommendedly through forms which call templates with the query).
Is there a solution that helps you manage database schema patches, preferably that runs in Node. I am looking at node-db-migrate which has support for MySQL but I want to be able to run plain vanilla SQL on it instead of using wrapper functions offered by this package.
Is there a solution that offers the same functionality but also lets you have plain SQL in patches?
I'm personally a fan of Sequelize, which has a (poorly named) sister project called Umzug designed to handle migrations. You can absolutely run vanilla SQL in a package like this, but be very careful doing so. Running raw SQL can be an easy way to do something like populate a new column with data (perhaps a new summary column that needs to be filled with the results of a more complex query you've been running until now). However, it can also make it very easy to make mistakes if you do this for things like ALTER TABLE. Whenever you can, it's best to use provided constructs for things like that.
I'm making a web service with Django that uses MySQL database. Clients interface with our database through URLs, handled by Django. Right now I'm trying to create a behavior that automatically does some checking/logging whenever a certain table is modified, which naturally means MySQL triggers. However I can also do this in Django, in the request handler that does the table modification. I don't think Django has trigger support yet, so I'm not sure which is better, doing through Django code or MySQL trigger.
Anybody with knowledge on the performance of these options care to shed some light? Thanks in advance!
There are a lot of ways to solve the problem you've described:
Application Logic
View-specific logic -- If the behavior is specific to a single view, then put the changes in the view.
Model-specific logic -- If the behavior is specific to a single model, then override the save() method for the model.
Middleware Logic -- If the behavior relates to multiple models OR needs to wrapped around an existing application, you can use Django's pre-save/post-save signals to add additional behaviors without changing the application itself.
Database Stored Procedures -- Normally a possibility, but Django's ORM doesn't use them. Not portable across databases.
Database Triggers -- Not portable from one database to another (or even one version of a database to the next), but allow you to control shared behavior across multiple (possibly non-Django) applications.
Personally, I prefer using either overriding the save() method, or using a Django signal. Using view-specific logic can catch you out on large applications with multiple views of the same model(s).
What you're describing sounds like "change data capture" to me.
I think the trade-offs might go like this:
Django pros: Middle tier code can be shared by multiple apps; portable if database changes
Django cons: Logically not part of the business transaction
MySQL pros: Natural to do it in a database
MySQL cons: Triggers are very database-specific; if you change vendors you have to rewrite
This might be helpful.
I have an indexed view that I need to specify the noexpand hint for in order for it to perform reasonably. Unfortunately as seen with regard to modifying the Linq to SQL generated T-SQL query from the NOLOCK hint it appears that there is no easy way to take advantage of these hints directly or is there?
My thought is that it would make sense to allow customization of this stuff through the use of attributes or declaratively through the dbml. Also since Linq to SQL seems to only work targeting SQL Server it only makes sense that we are also able to leverage these advanced features (if they exists). Regardless of the implementation though I'm interested in any creative ways of solving this problem.
I've found a workaround which appears to work but requires making a second View for each SQL View that one would want to use the NOEXPAND hint with. In the second view just select all of the fields from the original view and tack on the NOEXPAND hint. Any Linq to SQL query that needs to use the NOEXPAND hint can now just target that view that wraps the original.
More details can be found in this MSDN post.
One down side among others to consider when creating dependent views is that you will have to make sure to apply the creation scripts in the proper dependency order
Does anybody have any better alternatives? I would rather not have to create extra SQL Views just to support usage of this necessary optimizer hint.
I totally agree, but I do not believe there is such a method. In EF4 you can use the ExecuteStoreCommand that will let you execute SQL directly. That may be your only option if performance is unacceptable.
==EDIT==
You can also do this in LINQ to SQL through the ExecuteQuery method.
http://msdn.microsoft.com/en-us/library/bb399403.aspx