The column lists also add a layer of protection against logical errors if a column is added, removed, or altered without the INSERT statement also being updated.
#Load bulk data into sequel pro software
These are scenarios where change typically consist of column additions or alterations resulting from software releases. Use an INSERT with an explicit column list for applications where column lists, inputs, and outputs do not change often. With a variety of methods to insert data into SQL Server available, the first question we will ask is which syntax should we use? The answer is going to depend on your use-case and specifically what is most important to a given application. It is also useful for collecting a list of rows that were altered in a given TSQL statement, so we can take additional actions or report on them as needed. OUTPUT INSERTED is a great method for getting before & after data from DML statements. This is a far superior solution to iteration and/or using SCOPE_IDENTITY() and is the only easy way to capture data in this fashion with so little code. This is a huge convenience as we can use OUTPUT INSERTED in INSERT, DELETE, UPDATE, and MERGE statements to quickly pull before & after data for use in additional processing. The results show that we not only captured the account IDs, but also the previous and new values for the is_active flag.
An insert of this form will look like this: This leads us into the alternative way to insert data into an existing table, which is to do so without a column list. Insert Data into SQL Server Without an Explicit Column List
If you are dumping data to an output table and do not care about column order, typing, or quantity, then having to always adjust the column list to match the SELECT details may be a hassle and not worth the effort. This syntax has a downside, though, and that is maintainability in scenarios where table schema changes often and there is a desire to always SELECT *. Similarly, if you accidentally leave off a column from the column list, you’ll get this error:Īs a result, the explicitly provided column list makes it hard to accidentally leave columns out. If a NOT NULL column with no default constraint is left off of the list, an error will be thrown, similar to this: If a column is left off the list, then it will be made NULL. The primary benefit of inserting data with an explicit column list are that you document exactly what columns are being populated, and what data is being put into each column. For example, -1 is a poor choice for an integer column and is a lousy choice for a date column as each provides confusing meaning that is not intuitive to a developer or someone consuming this data. A default constraint should never be used to generate placeholder, fake, or obfuscated data. It is also useful when we wish to have a column that typically is not assigned a value, but requires one for an application or reporting purpose. Creating a default constraint can be useful for ensuring that a column can be made NOT NULL and always be assigned a value. We can see that the default value from the constraint was applied to account_notes, as expected. The results show us how the new row looks in our table: The following is the TSQL to create a table called dbo.accounts:
#Load bulk data into sequel pro full
This will allow us full reign to customize, test, and break it independently of anything else we are working on. By delving deeper into this topic, we can improve database design, script quality, and build objects that are easier to upkeep and less likely to break due to maintenance or software releases.Īll demos in this article will use new objects we create here. Performance, syntax, documentation, and maintainability will be evaluated for each method. In this article we will explore the different ways we can create and insert data into both permanent and temporary objects. How we generate and insert data into tables can have a profound impact on performance and maintainability! This topic is often overlooked as a beginner’s consideration, but mistakes in how we grow objects can create massive headaches for future developers and administrators. There are a variety of ways of managing data to insert into SQL Server.