| Change log entry 73562 | |
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| Processed by: | richwarm (2021-10-03 00:46:16 GMT) |
| Comment: |
<< review queue entry 69251 - submitted by 'goldyn_chyld' >> https://en.wikipedia.org/wiki/Null_(SQL) ------------------------------------ Editor: I think it's a concept in relational databases in general rather than being a specifically SQL concept. "A given field in a given record can contain data, or not. If you don’t enter a value into a field in a particular record, you might think that the field was simply empty, but life isn’t that simple. Instead the field is said to contain a null value. If, for example, a field is supposed to contain the phone number of a friend but you don’t know the phone number, you don’t enter any data. The field is then said to contain a null value." - from "Inside Relational Databases with Examples in Access" https://link.springer.com/chapter/10.1007%2F978-1-84628-687-2_31 |
| Diff: |
# 空值 空值 [kong1 zhi2] /null (SQL)/ + 空值 空值 [kong1 zhi2] /null value (in a relational database)/ |