Lưu trữ đồ thị và hiển thị đồ thị [tham khảo HA]

5.4Xây dựng câu truy vấn SeRQL

Một phần trong quá trình sinh câu SeRQL của hệ thống sẽ sử dụng lại giải thuật trước đây của VN-KIM Search [tham khảo Dũng], chỉ thêm vào những đoạn cần thiết để những câu truy vấn có tính từ.

Giải thuật đã có của VN-KIM Search như sau:

Generalize the query CG For each relation in the generalized query CG do { Get all neighbour concepts of the current relation //process each concept sequentially For each concept do { if the concept is new //i.e. not processed before { if the concept referent is “?” or “*” { if the concept referent is “?” { Assign to it a variable starting with “x” //e.g x1, x2, x3,... Assign to it a label variable starting with “z” //e.g z1, z2, z3,... Append these variables to the SELECT clause Append the “rdfs:label” statement for this concept to the FROM clause } if the concept referent is “*” { Assign to it a variable starting with “y” //e.g y1, y2, y3,... } Append the “rdf:type” statement for this concept to the FROM clause Append the constrained property statements for this concept to the FROM clause Assign to the constrained properties variables starting with “p” //e.g p1, p2, p3,... Append the property constraints to the WHERE clause } //end of “?” or “*” if the concept referent is specific, assign to it its identifier as a dummy variable Remember this concept having been processed } }//end of if new Assign to the current relation its URI Append the statement for the current relation with its neighbour concepts to the FROM clause } //process the disconnected concept nodes For each concepts that has not been visited yet, process it as above

[hình tham khảo Dũng]

Giải thuật đề tài này thêm vào để xử lý tính từ sẽ nhận kết quả của giải thuật trên làm đầu vào, rồi thêm những bộ phận cần thiết:

Giải thuật cho tính từ bình thường (dạng nguyên mẫu): Truy vấn tất cả thực thể phù hợp và trả về theo một trật tự

//Function: append ORDER BY clause for normal adjective to the input SeRQL Initialize new ORDER BY clause For each semantic relation generated from normal adjective { Append the its object’ variable to SELECT clause Identify the way of ordering //i.e DESC or ASC. Use a dictionary (XML file) Append to ORDER BY clause the variable of the relation’s object, and the way it is ordered }

Giải thuật cho tính từ so sánh nhất:

//Function: append WHERE clause for superlative adjective to the input SeRQL Initialize the WHERE, nested SELECT and nested FROM clause //select the value of all other entities which are also qualified, then use “>= ALL” or “<= ALL” to //find the entity that has the maximum and minimum value Identify whether “>= ALL” or “<=ALL” from the Top relation. Call this OP. Find the relation that is generated from superlative adjective { With its subject, create a new variable representing all others qualified entities. Call this the temporary subject. Then use the temporary subject to append all constraints on the subject to the nested FROM clause With its object, create a new variable representing all others qualified entities’ values. Call this the temporary object. Append the temporary object to the nested SELECT clause. Append the statement of this relation to the nested FROM clause. But use the temporary subject and temporary object as the 2 variables. Append to WHERE clause the object’s variable and the OP identified before. }