Can SQL Server piece together two different indexes in a single-table query, rather than just giving up and scanning a suboptimal clustered index? The short answer is: yes, in a fairly narrow band of conditions.
Continue readingTips
Use Ctrl+F1 as a “preview” button in SSMS
Every time I set up SQL Server Management Studio, I take the time to add a shortcut to the “Query Shortcuts” section of the options:
On the surface, these query shortcuts are just what the name implies – a key combination that you can press to run a command or execute a stored procedure. But there’s a hidden super power: whatever text you’ve selected in SSMS when you press the keyboard combination gets appended to the shortcut statement.
So if you select the name of a table, for instance “dbo.Votes”, and press Ctrl+F1, SSMS will run:
SELECT TOP (1000) * FROM dbo.Votes
This allows you to create a keyboard shortcut to instantly preview the contents of a table or view.
And you can select not just the name of one table, but any other query text you want to tack on:
Because we’ve selected both the name of a table and the next line, pressing Ctrl+F1 in SSMS will effectively run the following command:
SELECT TOP (1000) * FROM dbo.Votes AS v INNER JOIN dbo.VoteTypes AS vt ON v.VoteTypeId=vt.Id
You can go on to include as many joins, WHERE clauses, ORDER BY, as long as the syntax makes sense:
Remember that query shortcuts only apply to new windows, so if you change them, you’ll have to open a new window for the change to take effect.
STRING_SPLIT(), but for quoted names
Can you apply gaps and islands logic on a string? Sure you can.
Continue readingA simple database deploy pipeline using sqlpackage
I did some googling to see just how simple I could make a database deployment pipeline. I keep the DDL scripts in a git repository on the local network, but I can’t use Azure DevOps or any other cloud service, and I don’t have Visual Studio installed, so the traditional database project in SSDT that I know and love is unfortunately not an option for me.
So I googled a little, and here’s what I ended up doing.
Continue readingHow to add “created” and “updated” timestamps without triggers
You have a table that you want to add “created” and “updated” timestamp columns to, but you can’t update the application code to update those columns. In the bad old times, you had to write a trigger to do the hard work for you. Triggers introduce additional complexity and potentially even a performance impact.
So here’s a nicer way to do it, trigger-free.
Continue readingConnect using Windows authentication across domains
You’re a consultant or remote worker, and you’re connecting into your work or client network using a VPN. But when you try to connect to the SQL Server, you get this.
There are a few simple workarounds, each with their own pros and cons.
Continue readingOptimizing for something else
Ah, the feeling when you think of a new blog post topic, only to realize that you already wrote a post about that six years ago.
Well, I’ve done the work, so I might as well have a little fun with it.
Continue readingFun with VALUES
There’s more to the VALUES clause in T-SQL than meets the eye. We’ve all used the most basic INSERT syntax:
INSERT INTO #work (a, b, c)
VALUES (10, 20, 30);
But did you know that you can create multiple rows using that same VALUES clause, separated by commas?
INSERT INTO #work (a, b, c)
VALUES (10, 20, 30),
(11, 21, 31),
(12, 22, 32);
Note the commas at the end of each line, denoting that a new row begins here. Because this runs as a single statement, the INSERT runs as an atomic operation, meaning that all rows are inserted, or none at all (like if there’s a syntax issue or a constraint violation).
I use this construct all the time to generate scripts to import data from various external sources, like Excel, or even a result set in Management Studio or Azure Data Studio.
Here’s something you can try:
- Select a dataset from SSMS or Excel, copy it to the clipboard, and paste it into a new SSMS window.
- Select just one of the tabs, then use the “find and replace” feature (Ctrl+H) in SSMS to replace all tabs with the text
', '(including the apostrophes). - Now, add the text
('at the beginning of each line and'),at the end of each line. The last line obviously won’t need the trailing comma. If you’re handy with SSMS, you can do at least the leading values with a “box select”: holding down the Alt key as you make a zero-width selection over all the rows, then typing the text.
If all of this sounds like a lot of work for you, you might want to try out a little web hack that I wrote. It allows you to paste a tab-delimited dataset, just like the ones you get from Excel or the result pane in SSMS or ADS, into a window and instantly convert it into a T-SQL INSERT statement with the click of a button.
Pro tip: in SQL Server Management Studio, use Ctrl+Shift+C to copy not only the results, but also the column names!
Options
- First row has headers: instead of inserting the first row of the raw data, the script uses it to map the INSERTed values to the correct columns in the destination table.
- Fix nulls: Particularly when exporting from SSMS, we’ll lose information about which values are actually NULL and which ones are actually the text “NULL”. When this option is unchecked, the values will be treated as the text “NULL”, when checked, all values that consist entirely of the text “NULL” will have the surrounding apostrophes removed, so they become actual NULL values.
- Pretty: adds some indenting spaces to the output code. This increases the script size by a few bytes, but increases readability.
- Table name: Option table name to put in the INSERT INTO header of the script.
And to make sure you sleep well at night, the entire process on table.strd.co happens in the browser – nothing is ever uploaded to the Internet.
SSMS: Search and replace across multiple objects in a database
Here’s a quick tip that touches on one of the powerful SSMS tricks in my “Management Studio Level-Up” presentation. Say you have a potentially large number of database objects (procedures, functions, views, what have you), and you need to make a search-and-replace kind of change to all of those objects.
You could, of course, put the database in source control and use a proper IDE to replace everything, then check your code back into source control and commit it to the database. That’s obviously the grown-up solution. Thanks for reading this post.
But let’s say for the sake of argument that you haven’t put your database in version control. What’s the lazy option here?
Continue readingHow to use switching to make metadata changes online
Metadata changes, like modifying a clustered index, or many types of column changes, will create locks in SQL Server that will block users from working with that table until the change is completed. In many cases, those locks will extend to the system objects, so you won’t even be able to expand the “Tables” or “Views” nodes in Management Studio.
I want to show you how you can perform those changes using a copy of the table, then instantly switching the table with the copy. The secret is partition switching, and contrary to popular belief, you won’t need Enterprise Edition, or even partitions, to do it.
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