MySQL查询用下划线替换列中的空格

Question

I have a MySQL database table 'photos' with a column 'filename'. I need to replace the spaces in the filename column values with underscores. Is it possible with a single/multiple query? If so how?

Answer 1

You can use the REPLACE function :

REPLACE(str,from_str,to_str)

Returns the string str with all occurrences of the string from_str replaced by the string to_str .
REPLACE() performs a case-sensitive match when searching for from_str .

So, to replace all occurences of a character by another one in all lines of a table, something like this should do :

update photos set filename = replace(filename, ' ', '_');

ie, you search for ' ' in the column filename and use '_' instead ; and put the result back into filename .

Answer 2

update photos set filename = replace(filename,' ', '_');