我在 PostgreSQL 表上运行了此查询:
select * wkt from table where column <>'' and column is not null
..意外地收到了几行,该列中没有可见的值。为什么是这样?这些行的该列中是否存在一些“隐藏”值,或者损坏的表,或者其他什么?
最佳答案
t=# select ascii(chr(9));
ascii
-------
9
(1 row)
因此
select ascii(column) from table where column <>'' and column is not null
应该给出想法
https://www.postgresql.org/docs/current/static/functions-string.html
ASCII code of the first character of the argument. For UTF8 returns the Unicode code point of the character. For other multibyte encodings, the argument must be an ASCII character.
关于sql - PostgreSQL - 不为 null 且不为空字符串的空值,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/48447681/