I am developing a project with Xwiki. The project name is “Permission Request Form”. I connected the project to the MYSQL database and got all the tables. Can I get any data from Xwiki by adding a new table here? For example, how do I transfer the data in Xwiki to a table? How to transfer data from tables in MYSQL to Xwiki page?
Thanks for your help.
You can query xwiki objects using the query module and create SQL statements for your DB as described here.
I still think that there may be a better way to create your application (as I already said here), because you are duplicating data which is nothing I would aim for. But I/we can’t help you, given the little information you seem to be willing to share.
Xwiki itself has rich capabilities of object creation and saving, sparing you all the hassle to duplicate data.
I connected to a MYSQL Database with SQL Tools.I can do this,but can we get the data from a Textbox and transfer it to the MYSQL Database?
(For example.a Textbox created with HTML)
Yes you can, there are a ton of examples to create html forms including velocity, e.g. this one. And from velocity you are able to retrieve values from the database.
Frankly to me it looks like your are not extending xwiki as an application, because I see no clues that you are using any of the xwiki application features, it looks more like you are using xwiki as an pimped application server for your custom application. Correct me if I am wrong, but until then I’m out.
Thanks rbr. I am a student 
Problem solved
I have one more question
For example, I have two pages named P1 and P2(created with xwiki)
I have an HTML form on my P1 page (textfield, datepicker … etc) how do I export the data to the P2 page? With include Macro?