The INSERT statement and Column Defaults in Sql Server

When you INSERT into a table which has a column with a default value defined, and you omit that column from your statement, what will happen? The default will be written. What if you write an explicit Null (and the column is nullable)? In nearly all cases the Null is written.

You may not want this – it’s one of the cases where it might be nice if there were more than one type of Null, as some people advocated in the early days. Then we could distinguish a “known unknown” (© D. Rumsfeld) Continue reading

Advertisements

OPENROWSET and BULK INSERT (3)

{Previous Article in Series}
{Next}
This is the promised post about using a Powershell script to inspect large files. It won’t be possible to open a very large file in Excel of course, and some text readers may struggle under the weight of data. This script is an alternative that runs under most if not all versions of Windows, and doesn’t need an installation or a licence. Continue reading

OPENROWSET and BULK INSERT (2)

{Previous Article in Series}
{Next}

As a data warehouse developer you’ll probably have to load big files. Even if you’re not responsible for loads in PROD, you may well have to import data into the DEV database. There’s often an expectation that this shouldn’t take long, so if you hit any problems you could come under time pressure.

A toolkit and a methodical approach can help you to grind out a predictable result every time. I hope these notes may be some help. Continue reading

OPENROWSET and BULK INSERT (1)

{Next Article in Series}
Having found out a bit more about the way OPENROWSET works, it seems to me that if you are using a format file for an ad hoc INSERT of file data this is the only way to go. The rest of the statement works like standard SQL, so you have better control (compared with BULK INSERT) over which columns are selected and which are written. Continue reading