Java Programming

I guess "complex" might be in the eye of the beholder, but for me, this is sort of complex.

I've written a small java app that parses some SQL statements. I need to find SQL statements that have nested AND and/or OR predicates 3 or more levels deep in parenthesis.

The REGEX I've come up with works somewhat, but it is too broad and finds too many statements that are not applicable to my needs.

I've left two test statements uncommented - they pretty much sum up what I need to find and don't want to find. The Regex, however, matches both.

import java.util.regex.* ; 

	
public class SQL_Regex {


	public static void main(String[] args) {
			
			
						
		// Find AND/OR predicates nested at least 3 levels deep 
			
		String pat = new String(".+\\bwhere\\b.*\\(.*\\(.*\\(.+(\\bAND\\b|\\bOR\\b).+\\).*\\).*\\)"); 
		
		Matcher matcher = null ; 
		Pattern pattern = null ; 
		try { 
			pattern = Pattern.compile(pat, Pattern.CASE_INSENSITIVE ) ; 
		}
		catch (Exception e) { 
			System.out.println("Cannot compile REGEX pattern.  Exiting") ; 
			System.exit(-1) ; 
		}
		
		String sql[] = new String[] { 
			//"select * from table where (col1 = 1 and (col2 = 2 or (col3 = 3 or col4 = 4) ) )",  
			//"select * from table where ((( col1 = 1 and not col2 = 2)and(col3 = 3))or col4 = 4)" , 
			//"select * from table where (( col3 = 3 or col4 = 4))" ,  
			//"select * from table where  (col1 = col2)  and  (col3 = 3 or col4 = 4 )" ,  
			"select * from table where  (((col1 = col2)))  and  (((col3 = 3 )))" ,  // Do not want 
			"select * from table where (( col1 = 1 and not (col2 = 2 and(col3 = 3)))or col4 = 4)" } ;  // I want this
			


		for (String statement: sql) {    

			matcher = pattern.matcher(statement) ; 

			if (matcher.find()) { 
				System.out.println("Match YES: " + statement ) ; 
			}
			else { 
				System.out.println("Match NO : " + statement ) ; 
			}
			
		}
	}
}

Edited by: toddburch on Dec 15, 2008 3:30 PM