Skip to Content

Changes for page The EOModel

Last modified by Pascal Robert on 2012/03/10 15:42
From version 25.1
edited by Pascal Robert
on 2011/02/24 14:14
Change comment: There is no comment for this version
To version 23.1
edited by Pascal Robert
on 2011/02/27 12:28
Change comment: There is no comment for this version

Summary

Details

Page properties
Content
... ... @@ -209,6 +209,34 @@
209 209  
210 210  == Fetch Specs in Model ==
211 211  
212 +After you create and configure entities in EOModeler, you can also use it to build queries on those entities called fetch specifications. A fetch specification (a com.webobjects.eocontrol.EOFetchSpecification object) is the object Enterprise Objects uses to get data from a data source.
213 +
214 +Each fetch specification can contain a qualifier, which fetches only those rows that meet the criteria in the qualifier. A fetch specification allows you to specify a sort ordering to sort the rows of data returned. A fetch specification can also have other characteristics, as discussed in this chapter.
215 +
216 +Fetch specifications you build in EOModeler are referred to as named fetch specifications. To use a named fetch specification requires that you get hold of the model object in which the fetch specification exists. The code in Listing 7-1 retrieves a fetch specification called "MyFetch" in an entity named "Listing" by looking for it in all the models in the application's default model group.
217 +
218 +If you define a qualifier like this:
219 +
220 +{{code}}
221 +(askingPrice < $askingPrice) and (bedrooms = $bedrooms) and (bathrooms = $bathrooms)
222 +{{/code}}
223 +
224 +then the qualifier variables are replaced by 500000 (askingPrice), 4 (bedrooms), and 3 (bathrooms).
225 +
226 +{{code}}
227 +
228 +EOModelGroup modelGroup = EOModelGroup.defaultGroup();
229 +EOFetchSpecification fs = modelGroup.fetchSpecificationNamed("MyFetch", "Listing");
230 +fs = fs.fetchSpecificationWithQualifierBindings(dictionary);
231 +NSMutableDictionary dictionary = new NSMutableDictionary();
232 +dictionary.takeValueForKey("500000", "askingPrice");
233 +dictionary.takeValueForKey("4", "bedrooms");
234 +dictionary.takeValueForKey("3", "bathrooms");
235 +
236 +{{/code}}
237 +
238 +== Stored procedures ==
239 +
212 212  You can set up an EOModel so that Enterprise Objects automatically invokes a stored procedure for these operations on an entity:
213 213  
214 214  Insert to insert a new object into an entity