The Bit Bucket

I’m often working with developers who are migrating to SQL Server from Oracle. (Well, who can blame them?) One of the first questions that I’m often asked though, is where is the dual table?

In Oracle, a SELECT statement must have a FROM clause.

In SQL Server, this code will work fine:

SELECT UPPER('Hello');

It will just return the string converted to upper case. You can alias it as well:

SELECT UPPER('Hello') AS Greeting;

Again, you’ll get the converted string but the column will be called Greeting.

2020-05-29

Another question that I keep seeing on SQL Server forums is:

Why do my SQL Server backup files keep getting much larger?

The backup commands that the poster is using look like this:

BACKUP DATABASE @DatabaseName
    TO DISK = @BackupFile
    WITH COMPRESSION;

When you do a backup, what you’re actually doing is adding a backup set to a media set. Each time you do a backup like that, you’re adding another backup set to the same media set.

2020-05-28

I’ve found the sys.time_zone_info system view that was added in SQL Server 2016, really useful in a number of situations. It returns the name of each timezone, along with their current offset from UTC (like +01:00 or -07:00 ) and if they are or are not currently in daylight savings time.

However, what I’ve found myself needing to do is to convert the timezone offset part to a decimal number of hours.

2020-05-27

I work with many different clients and I see work that’s great and I also see work that’s not so great. But the work that frustrates me the most, is inconsistent work.

When we built a house a while back, there are a number of rooms that have a combination light switch like the one shown in the main image. One switch is for the light, one is for something else: most likely a fan in a bathroom, etc.

2020-05-26

When you’re writing T-SQL code, it’s also common to need to work out how far apart two dates are, or it could even be dates and times.

The DATEDIFF() function does that. In this case I’m asking how many days is it from 28th of February 2019 to 31st of July 2019?  The answer is:

So it says the difference is 153 days. Now we could have used any of those other intervals for that. I mentioned them before in this post.

2020-05-25

I used to be able to tell when someone moved from working with Access databases and arrived at SQL Server. What was the tell-tale sign?

All their tables had names like tblCustomers.

We’ve pretty much stopped people doing that, and we also have pretty much stamped out Hungarian Notation, at least in SQL Server.  We don’t use variable names like @intCreditRating, although there are still a number of people that I see clinging to Hungarian Notation when they work with SSIS, particularly in their .NET code. In their code, you’ll see values like strCustomerName and so on. The irony is that .NET developers long since moved past doing that, yet people writing .NET code in SSIS still do it.

2020-05-22

I answered a forum question the other day about how to list all the columns in a SQL Server database. That’s straightforward enough, but they also asked for all the extended properties for the column.

In case you need to do this, here’s some code:

SELECT s.[name] AS SchemaName,
       t.[name] AS TableName,
       c.[name] AS ColumnName,
       c.is_nullable AS IsNullable,
       typ.[name] AS DataTypeName,
       c.max_length AS MaximumLength,
       c.[precision] AS [Precision],
       c.scale AS Scale, 
       ep.ExtendedPropertyName,
       ep.ExtendedPropertyValue
FROM sys.columns AS c
INNER JOIN sys.tables AS t
ON t.object_id = c.object_id 
INNER JOIN sys.schemas AS s
ON s.schema_id = t.schema_id 
INNER JOIN sys.types AS typ
ON typ.system_type_id = c.system_type_id 
AND typ.user_type_id = c.user_type_id 
OUTER APPLY 
(
    SELECT ep.[name] AS ExtendedPropertyName,
           ep.[value] AS ExtendedPropertyValue
    FROM sys.extended_properties AS ep
    WHERE ep.major_id = c.object_id 
    AND ep.minor_id = c.column_id
) AS ep
WHERE t.is_ms_shipped = 0
AND t.[name] <> N'sysdiagrams'
ORDER BY SchemaName, TableName, ColumnName, ExtendedPropertyName;

How it works

I start with the sys.columns view and join it to sys.tables and sys.schemas, to get the schema and table name. The other reason is to make sure it’s not a Microsoft-supplied table. I also wanted to exclude the sysdiagrams table that is created when you first create a database diagram using SQL Server Management Studio. (Curiously, that one’s not flagged as a Microsoft-supplied table).

2020-05-21

The DatesBetweenNoWeekends function in our free SDU Tools for developers and DBAs, is really popular. It provides a range of dates between starting and ending dates, ignoring weekends.

DatesBetweenNoWeekends is a simple table-valued function that takes two parameters:

@StartDate - the first date to return @EndDate - the last date to return

The columns returned are:

DateNumber - a sequential number for the dates returned DateValue - the date

Find out more

You can see it in action in the main image above, and in the video here. The full current version of the code is also shown below:

2020-05-20

In some countries, post office boxes are quite anonymous. And for that reason, some vendors aren’t keen to send goods to PO Boxes. But that’s not all countries. In Australia, for example, you have to provide all sorts of ID to the post office to be able to get one.

Why PO Boxes?

The fundamental reason that many people use PO Boxes is to have a relatively safe location for their mail to be collected. At so many houses, letter boxes are quite unsafe. And for people living in apartments, the situation is often far, far worse.

2020-05-19

When you’re writing T-SQL, you might also need to add intervals to dates, perhaps add days or subtract days and so on. The DATEADD() function is the one that we can add or subtract intervals to the date and time.

Now in the example shown here, what I’ve said is in 20190228 or  28th of February 2019. I want to add on 12 days. To subtract 12 days, I would have just put -12 instead of 12. You can see the output here:

2020-05-18