CODEWITHSUNDEEP
javaregex
Ali
Ali

Reputation: 8100

Split SQL Select Statement with RegEx

I want to find the whole list of columns in the an SQL Select statement with Regex.

For example,

Select col1, col2,col3 from tab1;

Required

[1]: col1
[2]: col2
[3]: col3

One way is this regex

select.*from;

and then split the string. Is there any other more efficient method?

Thanks

Upvotes: 0

Views: 1891

Answers (1)

Tim Pietzcker
Tim Pietzcker

Reputation: 336198

I'd say that your version is the most efficient way.

You could construct a regex that grabs all those in a single run, but it's surely not going to be as fast as what you're doing, and it only looks ahead to see a from following, not behind whether there's a select behind it:

Pattern regex = Pattern.compile("\\w+(?=\\s*(?:,|\\bfrom\\b))(?=.*\\bfrom\\b)");
Matcher regexMatcher = regex.matcher(subjectString);
while (regexMatcher.find()) {
    matchList.add(regexMatcher.group());
}

So all in all, I'd say go with what you have. Maybe make the asterisk lazy:

select.*?from

Upvotes: 1

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