Tagged articles - SQL

Fetching the data in it's original form from SQL relational database is the most common way of getting the data stored. For example, to get all column from Products table in Northwind database is pretty straight forward. ...read more

People often try to compare Dapper and Entity Framework. Although they both have same goal and that is reading and modifying the data against the database, they take completely different approach in doing so and therefore this comparison is not really valid. Entity framework is more robust as the name says framework, while Dapper is simple object mapper which is down the line set of extension methods on top of the ADO classes which allow easier manipulation with data in the database...read more

I while ago I wrote an article on how to Access multiple databases from the same DbContext in EF Core which relies on interceptors to mutate the SQL query diring execution. This code works just fine and it updates the command prior to it's execution, but it lacks in option to inject registered services to it's constructor as i used new keyword to initialize class instances. Adding interceptor without dependency injection ...read more

Not so while ago I wrote an article on Seeding data with Entity Framework Core using migrations. This approach relies on EF Core migrations to ensure seeding of specific data is done only once using __EFMigrationsHistory table to track structural migrations as well as data seeding migrations. In large number of cases this approach works just fine and you do not need to do any adjustments or add any additional tables, just use migrations mechanism out of the box...read more

Object relational mappers or ORMs are a great tool which can significantly reduce application development time, but if they are not use wisely they can cause bottlenecks and performance issues. Same goes for dependency injection containers. The lifetime of the components, especially the ones that can cause recurse locks like SQL Server connections must be as short as possible and they should be released as soon as work is done. ...read more

Over the time various techniques to manipulate database data have evolved in .NET. Entity Framework is certainly the most advanced one, but for small ad hock applications where you have few inserts to deal with, ADO is still the fastest way to write data to the database...read more

JSON is the most commonly used data fromat nowdays. It is lighter than XML, more readable and it's sindax complies with most OOP C-Like lnguages such as Java, JavaScript and C#. There is not really many downsides of using JSON, so that is one of the rasons everyone is using it in one way or another. ...read more

Sending email from SQL is not a difficult to achieve, but generating rich HTML content might be. SQL Server itself is not built as a text processor, first approach would be to build HTML by simple concatenating the string elements. This approach will work, but over time it will become more and more difficult to maintain especially if you need to add layout elements over time. ...read more

In case you need to handle IP addresses in SQL, they are not much useful as string values. To do anything with them rather then just storing and retrieving (checking the ranges for example) you need to split IP address to segments (octets). The following is modified method I run into online. ...read more

Probably the most common error developers make in queries is dealing with date ranges and most of the time it is because of missing the minimum and maximum time of the specific date. Month ...read more

In case your data in tables needs to have unique constraint based on more than one value in the row, the proper solution for that would be a composite key. ...read more

Nowadays, in the years of ORM, barely anyone thinks about stored procedures, but they are still there and accessing and reading data with ADO and SqlDataReader ist still the fastest way. Stored procedures are validated, parsed and compiled in SQL server, so these steps are not required to be performed versus plaint text query (which is what entity framework generates for accessing data). ...read more

Entity framework is an awesome tool for working with database in .net, but sometime you have to get back to old fashion ADO for the performances. The bad thing is that as soon as you get back to ADO, you have to deal with SqlDataReader, DataTable and DataSet classes...read more

Passing complex data to and from stored procedures has always been a tricky one. The most elegant way to pass values to a stored procedure is to use predefined data types in SQL Server...read more

When working on an app you create all your stored procedures, functions, tables, view and other objects in a development database (or t least it should be like that). A small but annoying problem occurs when you have to migrate your stored procedures to test or production database. Imagine during development you had let's say 20 stored procedures...read more