This function calculates text values of nodes from the scope, and checks whether the current text value contains any fragment that matches the query. When the first match is found, the rest of the node-set is ignored the boolean 'true' is returned. If the node-set ends before any match is found, 'false' is returned.
The text_contains() function may be used only in XPath expressions that are arguments of xcontains(). This restriction is for optimization purposes. When Virtuoso executes an SQL statement that uses xcontains(), it performs some sophisticated free-text search, and it applies the XPath expression not to all available documents but only to documents that satisfied the free-text search criterion. Moreover, the server uses the intermediate free-text data to optimize the search inside a selected document.
Returns a boolean: True or False.
When the first match is found, the rest of the node-set is ignored the boolean 'true' is returned. If the node-set ends before any match is found, 'false' is returned.