public static String suffixWithChar(String str, char padChar, int repeat){
        StringBuilder stringBuilder = new StringBuilder(str);
        for(int i=0; i<repeat; i++){
            stringBuilder.append(padChar);
        }

        return stringBuilder.toString();
    }
parse multi join table name, child query RealTabName is null
@param leftJoin
@param aliasAndRealTabName
core/src/main/java/com/dtstack/flink/sql/util/ParseUtils.java