Question

I need a regex for my PHP script that will help me manipulate some strings using preg_replace.

For example, say I have the following string:

myvar = first_value AND var2 = second_value

I would like to have it converted to:

myvar = 'first_value' AND var2 = 'second_value'

However, I would also like to have it ignore when there is already a single quote around the value. So myvar = first_value AND var2 = 'second_value' will become myvar = 'first_value' AND var2 = 'second_value' and not myvar = 'first_value' AND var2 = ''second_value''.

I would also like it to deal with spaces within sub-strings when there is already a single quote around the value. So myvar = first_value AND var2 = 'second value' will become myvar = 'first_value' AND var2 = 'second value' and not myvar = 'first_value' AND var2 = 'second' value'.

NOTE: At no time will the string contain variable assignment with unquoted string values that have spaces in them i.e. myvar = first value is a scenario that will never arise. However, the string can contain any other character, even special characters e.g. myvar = &%$@_imspecial_* is totally valid.

The PHP Code I was working with looked something like below (#DontLaugh):

$col_clause_str = "myvar = first_value AND var2 = second_value";
$replace_pattern_str = '/([\w\@\-]+)\s*(\=|\>|\>\=|\<|\<\=)\s*\'{0,1}([\w\@\.\:\+\-\/\|\{\}\[\]\~\%\$\*\!]+)\'{0,1}/i';
$replace_str = '\1 \2 \'\3\'';
$col_clause_str = preg_replace($replace_pattern_str, $replace_str, $col_clause_str);

How can I improve this Regex?!

Thanks in advance.

EDIT:
I updated the question to be more descriptive.

Answer 1

You can replace this regex: –

"/(?<==\s)(\w+)/i"

with: –

'\1'

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Update: –

Ok, for your updated question, you can use this regex: –

"/(?<==\s)([^\s']+)/i"

And replace it with same string – '\1'