15. The apparatus of claim 12 , wherein the attribute information about the target field further comprises a screening condition of the target field, the screening condition of the target field being used for the query engine to perform screening processing on the obtained numerical values corresponding to the target field.
12. The apparatus of claim 8 , wherein the programs include instruction for: receiving attribute information about a candidate field described in a second language; parsing said attribute information about the candidate field described in the second language so as to obtain said attribute information about the candidate field; and removing attribute information about an incorrect candidate field from the attribute information about said candidate field so as to obtain the attribute information about the target field.