DATASaberのRikaです。（DATASaberって何という方はこちら） 便利なのに、あまり知られていない気がするTipsの布教活動中です。 今回のテーマは「NULLの0埋め」です！ NULLを0埋めする前に 売上実績のない月・カテゴリが空白（NULL）になってしまう。 こういう時 ...

翔泳社では、「独習」「徹底入門」「スラスラわかる」「絵で見てわかる」「一年生」などの人気シリーズをはじめ、言語や開発手法、最新技術を解説した書籍を多数手がけています。プロジェクトマネジメントやチームビルティングといった管理職向けの ...

-- You might think that the phrase dept=NULL would work here but it doesn't - you can use the phrase dept IS NULL -- That's not a proper explanation -- No it's not ...

There is no doubt that SQL has made NULL pervasive among database products. However, as Chris Date makes clear through numerous counter-examples, NULL can have no place in the relational algebra. This ...

just some info for anyone else who's not a sql guru:<BR><BR>i did the following selection on a table:<BR><BR>SELECT * FROM Table WHERE myField <> 'active'<BR><BR>the values in that colum are a mix of ...

IS NULL and IS MISSING are predicates that test for a missing value. IS NULL and IS MISSING are used in the WHERE, ON, and HAVING expressions. Each predicate resolves to true if the sql-expression's ...