How to parser select statement contained '@'?

[jisonami]

when I try to parser a select statement contained '@', like this "SELECT @Rowno := @Rowno + 1 from (SELECT (@Rowno := 0) from dual) r;", I get a TokenMgrError.

net.sf.jsqlparser.parser.TokenMgrError: Lexical error at line 2, column 10. Encountered: "r" (114), after : "@"
at net.sf.jsqlparser.parser.CCJSqlParserTokenManager.getNextToken(CCJSqlParserTokenManager.java:1750)
at net.sf.jsqlparser.parser.CCJSqlParser.jj_scan_token(CCJSqlParser.java:9139)
at net.sf.jsqlparser.parser.CCJSqlParser.jj_3R_294(CCJSqlParser.java:6500)
at net.sf.jsqlparser.parser.CCJSqlParser.jj_3R_235(CCJSqlParser.java:6546)
at net.sf.jsqlparser.parser.CCJSqlParser.jj_3R_150(CCJSqlParser.java:6089)
at net.sf.jsqlparser.parser.CCJSqlParser.jj_3R_67(CCJSqlParser.java:6304)
at net.sf.jsqlparser.parser.CCJSqlParser.jj_3_16(CCJSqlParser.java:6577)
at net.sf.jsqlparser.parser.CCJSqlParser.jj_2_16(CCJSqlParser.java:5292)
at net.sf.jsqlparser.parser.CCJSqlParser.SelectBody(CCJSqlParser.java:845)
at net.sf.jsqlparser.parser.CCJSqlParser.Select(CCJSqlParser.java:837)
at net.sf.jsqlparser.parser.CCJSqlParser.SingleStatement(CCJSqlParser.java:74)
at net.sf.jsqlparser.parser.CCJSqlParser.Statement(CCJSqlParser.java:54)
at net.sf.jsqlparser.parser.CCJSqlParserUtil.parse(CCJSqlParserUtil.java:49)

But, I need to parser these select statement, in order to optimize some "select count" statement in my paging component.Help, please!

[wumpz]

The problem is not the @. I was able to successfully parse:
SELECT @rowNO from (SELECT @rowNO from dual) r

The problem seems to be the expressions:
@rowNO := @rowNo + 1

[jisonami]

think you! can I parse ":=" as "+" ? when I repalce ":=" as "+", all thing is OK!

[jisonami]

Is not support function “if”？
And is not support table alias ”of”？