how to search documents that value is ";"

[juan lu]

Hi,

I have a field named "bidcode" in my Index,the value is like this:

Doc1:    ;
Doc2:    ;a0213;a0245
Doc3:    ;
Doc4:    ;
Doc5:    ;a2148;a0214
……

how can I search all the documents that the value of this field is ";"?

I use the  Query like this:
Query query = QueryParser.parse("bidcode:\";\"", "content", analyzer);          

It find nothing.  Why is that?

Many thanks for help!