如何使用 sql 样式转义正则表达式匹配字符串？

Question

examples:

"""Romeo and Juliet"""
'another string that is quoted with '' single quotes'

the problem is that the string can have characters used for db escaping even in it's beginning and end, so regex should look if given char is used in sequence of odd length that is 1,3,5... at the end of matched string

Answer 1

Try this regex: '(?:[^']|'')*' for single quotes. The same for double quotes, ie full regex:

'(?:[^']|'')*'|"(?:[^"]|"")*"

In string hello 'my ''beautiful''' 'world'! """Romeo and Juliet""" hello 'my ''beautiful''' 'world'! """Romeo and Juliet""" it will find:

1. 'my ''beautiful'''
2. 'world'
3. """Romeo and Juliet"""

Answer 2

Where your string includes (or might include) characters that cause problems in your sql, you should always escape.

If you're using PHP with a mysql database, use mysql_real_escape_string($text); ( docs )

For other databases and languages, you'll have to check for your specific purposes, but there's likely to be an existing method.