xml - How to check for text node of an element in xmltype oracle -

using following query,

select *   sampletable   xmlexists('/books/book[@max="30"]' passing xmlcolumn);

but want know , how check plain text content of element, like

select *   sampletable   xmlexists('/books/book="content"' passing xmlcolumn);

to check if there book node text node equals content (from xpath terms return book nodes), do:

select *   sampletable   xmlexists('/books/book[.="content"]';

to check if there books nodes child node equals content (from xpath terms return books nodes), do:

select *   sampletable   xmlexists('/books[book="content"]';

Brent