Question

I want to find/replace a character/pattern ONLY inside SQL comments ( single line comments — and block comments /* */). The source string is an SQL script.

At the moment I am searching for a semi-colon (;) within comments and want to replace it with blank space.

Source

CREATE OR REPLACE PROCEDURE TESTDBA.PROC_REUSING_BINDED_VAR_N_DSQL

 AS
        a NUMBER:=2;
        b NUMBER:=3; -- jladjfljaf; lakjflajf
-- alksdjflkjaf ladkjf 
        v_plsql_tx VARCHAR2(2000);
    begin
        v_plsql_tx := 'BEGIN ' || ' :1 := :1 + :2; ' || 'END;';
        execute immediate v_plsql_tx
        using in out a, b;
        insert into testdba.NEW_TESTING_TABLE(CHARACTER_VALUE) VALUES('a='||a);
   end PROC_REUSING_BINDED_VAR_N_DSQL;
-- lajdflajf

/*lakjdfljalfdk; alkdjf*/

/*asdf 
;
asdfa*/

/*
    adf
asd asdf


*/

Can you please suggest something.

Thanks

Answer 1

I would do this like this :

    try {
    Pattern regex = Pattern.compile("(?:/\\*[^;]*?\\*/)|(?:--[^;]*?$)", Pattern.DOTALL | Pattern.MULTILINE);
    Matcher regexMatcher = regex.matcher(subjectString);
    while (regexMatcher.find()) {
        // matched text: regexMatcher.group()
        // match start: regexMatcher.start()
        // match end: regexMatcher.end()
    } 
} catch (PatternSyntaxException ex) {
    // Syntax error in the regular expression
}

The above will give you all comments without ‘;’. Then I would iterate line by line through the sql file and when I encountered a line which had a comment I would check to see if that line is in my list of matches – if not then I would search replace ; with ‘ ‘ in the whole comment. Of course you will have to find where the comment ends but this is easy — ends in the same line and /* and when the first */ is found. This way you can change any number of ; with the same code.