问题
Is it possible to do a "find and replace" with the following?
UPDATE __table__ SET __column__ = replace(__column__, ' ', '_');
How do I define an array of strings to be found (',', ';', ':', ' ') to replace with '_'?
回答1:
Read the section about Bracket Expressions which explains how to search for characters within a string to replace
but this should work for you
UPDATE __table__ SET __column__ = regexp_replace( __column__, E'[\\s,;:]','_','g')
回答2:
regexp_replace() is powerful, versatile ... and slow.
If you can, use the plain (less powerful and versatile) replace(), which is much faster.
For the simple case at hand (replace a list of single characters with another single character) use translate() - even simpler and faster. And also much less error prone.
UPDATE tbl
SET col = translate(col, ',;: ', '____')
WHERE col <> translate(col, ',;: ', '____'); -- avoid empty updates
Only update rows that actually change. It's a common (possibly expensive) mistake to update all rows unconditionally. Details:
- How do I (or can I) SELECT DISTINCT on multiple columns?
Note that this only replaces the space character (' ') while the class shorthand \s in a regular expression matches all whitespace characters of the the character class [[:space:]].
来源：https://stackoverflow.com/questions/27691393/find-multiple-strings-and-replace-with-single-string-in-postgres