4 bài viết
NULL handling is one of the trickier aspects of data modeling and data manipulation with SQL. Let’s start with the fact that an attempt to explain exactly what a NULL is is not trivial in and of itself. Even among people who do have a go...
Lưu bởi: Huy Vũ
This article is the second in a series on NULL complexities. Last month I introduced the NULL as SQL’s marker for any kind of missing value. I explained that SQL doesn’t provide you with the ability to distinguish between missing and app...
Lưu bởi: Huy Vũ
This article is the third installment in a series on NULL complexities. In Part 1 I covered the meaning of the NULL marker and how it behaves in comparisons. In Part 2 I described the NULL treatment inconsistencies in different language ...
Lưu bởi: Huy Vũ
This article is Part 4 in a series about NULL complexities. In the previous articles (Part 1, Part 2, and Part 3), I covered the meaning of the NULL as a marker for a missing value, how NULLs behave in comparisons and in other query elem...
Lưu bởi: Huy Vũ
