I m trying to figure out how to concatenate attribute names. I have a county and a district attribute that I want to query like
[NSPredicate predicateWithFormat:#"county + district contains[cd] %#",searchBar.text]
gives me unimplemented SQL generation for predicate error. and I am not sure how to implement NSPredicate.
Thanks
This should give you an idea of how to do some more complicated searching. It will match queries for "county district", "district county", etc.
NSArray *searchTerms = [searchBar.text componentsSeparatedByString:#" "];
NSString *predicateFormat = #"(county contains[cd] %#) OR (district contains[cd] %#)";
NSPredicate *predicate;
if ([searchTerms count] == 1) {
NSString *term = [searchTerms objectAtIndex:0];
predicate = [NSPredicate predicateWithFormat:predicateFormat, term, term];
} else {
NSMutableArray *subPredicates = [NSMutableArray array];
for (NSString *term in searchTerms) {
NSPredicate *p = [NSPredicate predicateWithFormat:predicateFormat, term, term];
[subPredicates addObject:p];
}
predicate = [NSCompoundPredicate andPredicateWithSubpredicates:subPredicates];
}
[fetchRequest setPredicate:predicate];
See Cocoa Is My Girlfriend: Adding iTunes-style search to your Core Data application for more explanation.
I ended up implementing another field as concatenating the two variables(district+country) and perform the query on that variable.
I did something similar and concluded that like cekisakurek, the best method was to concatenate the fields into a common field (more relevant for first/last name)
- (NSString *)fullName {
return [NSString stringWithFormat:#"%# %#", self.firstName, self.lastName];
}
and then filtered on this field using 'contains[cd]'
[NSPredicate predicateWithFormat:#"fullName contains[cd] %#", self.searchBar.text];
[NSPredicate predicateWithFormat:#"county contains[cd] %# AND district contains[cd] %#",searchBar.text,searchBar.text];
Just try the above lines of code, it would helps you.
Related
Does the IN operator work for filtering SBElementArrays? I have been trying to use it but it always returns a NULL array.
My code (hexArray will typically have more elements):
SBElementArray *musicTracks = [libraryPlaylist fileTracks];
hexArray = [NSArray arrayWithObject: #"3802BF81BD1DAB10"];
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"ANY %K IN %#",#"persistentID",hexArray];
NSLog(#"%#", [[musicTracks filteredArrayUsingPredicate:predicate] valueForKey:#"persistentID"]);
NSLog(#"%#", hexArray);
NSLog(#"%#", predicate);
Output:
2013-05-26 12:59:29.907 test[1226:403] (null)
2013-05-26 12:59:29.907 test[1226:403] (3802BF81BD1DAB10)
2013-05-26 12:59:29.908 test[1226:403] ANY persistentID IN {"3802BF81BD1DAB10"}
I have tried setting the predicate to:
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"ANY %K == %#",#"persistentID",hexArray];
Output:
2013-05-26 13:03:04.629 test[1258:403] (3802BF81BD1DAB10)
2013-05-26 13:03:04.630 test[1258:403] (3802BF81BD1DAB10)
2013-05-26 13:03:04.630 test[1258:403] ANY persistentID == {"3802BF81BD1DAB10"}
And this works fine. But I would like the IN functionality.
Instead of doing
persistentID IN ('abc', 'abc', 'abc', ...)
you can do
persistentID == 'abc' OR persistentID == 'abc' OR ...
It seems to work pretty fast.
NSMutableArray *subPredicates = [NSMutableArray arrayWithCapacity:persistentIDs.count];
for (NSNumber *persistentID in persistentIDs) {
[subPredicates addObject:pred(#"persistentID == %#", persistentID.hexValue)];
}
NSPredicate *predicate = [NSCompoundPredicate orPredicateWithSubpredicates:subPredicates];
[tracks filterUsingPredicate:predicate];
NSLog(#"%ld", tracks.count);
Try using CONTAINS[c]
Ex:-
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"ANY %# CONTAINS[c] %k",hexArray, #"persistentID"];
I ended up just looping through all the elements of hexArray and using an equality predicate on each pass. Probably not the most efficient, but it works.
for (NSString *hexID in hexArray){
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"persistentID == %#",hexID];
iTunesTrack *track = [[musicTracks filteredArrayUsingPredicate:predicate] objectAtIndex:0];
[track duplicateTo:playlist];
}
Your predicate should be %K IN %# (without the ANY), if I understand your intention correctly (get all the tracks that have one of the IDs in the array).
For some reason, this doesn't work with SBElementArray, but you could simply convert it to a regular NSArray before applying the predicate (an NSSet should work too, and might be more efficient):
SBElementArray *musicTracks = [libraryPlaylist fileTracks];
NSArray *musicTracksArray = [NSArray arrayWithArray:musicTracks];
NSArray *hexArray = [NSArray arrayWithObjects: #"CE24B292556DB1BA", #"CE24B292556DB1F0", #"CE24B292556DB1C4", nil];
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"%K IN %#", #"persistentID", hexArray];
NSLog(#"%#", [[musicTracksArray filteredArrayUsingPredicate:predicate] valueForKey:#"persistentID"]);
Scripting Bridge technically supports the IN operator, in that it will construct a properly-formed Apple event for it, but most applications don't understand it. The best workaround is the chained OR tests as suggested by NSAddict.
I'm trying to filter a UITableView's data using a UISearchDisplayController and NSCompoundPredicate. I have a custom cell with 3 UILabels that I want to all be filtered within the search, hence the NSCompoundPredicate.
// Filter the array using NSPredicate(s)
NSPredicate *predicateName = [NSPredicate predicateWithFormat:#"SELF.productName contains[c] %#", searchText];
NSPredicate *predicateManufacturer = [NSPredicate predicateWithFormat:#"SELF.productManufacturer contains[c] %#", searchText];
NSPredicate *predicateNumber = [NSPredicate predicateWithFormat:#"SELF.numberOfDocuments contains[c] %#",searchText];
// Add the predicates to the NSArray
NSArray *subPredicates = [[NSArray alloc] initWithObjects:predicateName, predicateManufacturer, predicateNumber, nil];
NSCompoundPredicate *compoundPredicate = [NSCompoundPredicate orPredicateWithSubpredicates:subPredicates];
However, when I do this, the compiler warns me:
Incompatible pointer types initializing 'NSCompoundPredicate *_strong'
with an expression of type 'NSPredicate *'
Every example I've seen online does this exact same thing, so I'm confused. The NSCompoundPredicate orPredicateWithSubpredicates: method takes an (NSArray *) in the last parameter, so I'm REALLY confused.
What's wrong?
First of all, using "contains" is very slow, consider mayber "beginswith"?
Second, what you want is:
NSPredicate *predicate = [NSCompoundPredicate orPredicateWithSubpredicates:subPredicates];
Three, you could've just done something like:
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"SELF.productName beginswith[cd] %# OR SELF.productManufacturer contains[cd] %#", searchText, searchText];
orPredicateWithSubpredicates: is defined to return an NSPredicate*. You should be able to change your last line of code to:
NSPredicate *compoundPredicate = [NSCompoundPredicate orPredicateWithSubpredicates:subPredicates];
... and still have all of the compoundPredicates applied.
Here's an useful method i created based on the answers above (which i thank very much!)
It allows to create an NSPredicate dynamically, by sending an array of filter items and a string which represents the search criteria.
In the original case, the search criteria changes, so it should be an array instead of a string. But it may be helpful anyway
- (NSPredicate *)dynamicPredicate:(NSArray *)array withSearchCriteria:(NSString *)searchCriteria
{
NSArray *subPredicates = [[NSArray alloc] init];
NSMutableArray *subPredicatesAux = [[NSMutableArray alloc] init];
NSPredicate *predicate;
for( int i=0; i<array.count; i++ )
{
predicate = [NSPredicate predicateWithFormat:searchCriteria, array[i]];
[subPredicatesAux addObject:predicate];
}
subPredicates = [subPredicatesAux copy];
return [NSCompoundPredicate orPredicateWithSubpredicates:subPredicates];
}
I have this predicate:
NSPredicate * thePredicateKeyword = [NSPredicate predicateWithFormat:#"any keywords.thekeyword beginswith [cd] %#", searchTerm];
Basically each business have many to many relationship with keywords.
But suppose I do not have one searchTerm. Say I have an array.
How would I do so?
I suppose I can just make predicate for each and combine them with or predicate, etc.
However, is there a way to more efficiently do this using in keywords or stuff like that?
What about a function that returns something like this:
-(NSPredicate *)createCompoundPredicateForSearchTerms:(NSArray *)searchTerms
{
NSMutableArray *subPredicates = [[NSMutableArray alloc] init];
NSEnumerator *searchTermEnum = [searchTerms objectEnumerator];
NSString *searchTerm;
while (searchTerm = [searchTermEnum nextObject]) {
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"keywords.thekeyword beginswith [cd] %#", searchTerm];
[subPredicates addObject:predicate];
}
return [NSCompoundPredicate andPredicateWithSubpredicates:subPredicates];
}
This is what I actually use. However, the anwer I chose is what inspire it.
NSArray * keywords = [searchTerm componentsSeparatedByString:#" "];
NSMutableArray * keywordPredicates = [NSMutableArray array];
for (NSString * aKeyword in keywords) {
NSPredicate * thePredicateKeyword = [NSPredicate predicateWithFormat:#"any keywords.thekeyword beginswith [cd] %#", aKeyword];
[keywordPredicates addObject:thePredicateKeyword];
}
NSPredicate * thePredicateKeyword = [NSCompoundPredicate orPredicateWithSubpredicates:keywordPredicates];
return thePredicateKeyword;
So I have 4 text fields in which a user can use to narrow down table results in order to find an exact place. My problem is that since a user does not have to type something in each text field, I can't simply use AND in my predicate.
Right now I have the opposite from what I'd like my app to do. If one types in a City and a State, my predicate shows more results rather than narrowing the results. Which makes perfect sense to why its doing that.
Other than creating many if statements based on what text fields are empty or not, is there an better way around this?
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"(place CONTAINS[c] %#) OR (city CONTAINS[c] %#) OR (state CONTAINS[c] %#) OR (zip CONTAINS[c] %#)",
userPlace, userCity, userState, userZip];
This should work:
fetchRequest.predicate = nil;
NSMutableSting *predicateString = [NSMutableString string];
NSArray *attributeNames = #[#"name", #"city", #"state", #"zip"];
int i = 0;
for (NSString *s in #[userName, userCity, userState, userZip]) {
if (s && ![s isEqualToString:#""]) {
[predicateString appendFormat:#"%#",
predicateString.length ? #" AND " : #""];
[predicateString appendFormat:#"(%# CONTAINS[c] '%#')",
attributeNames[i], s];
}
i++;
}
if (predicateString.length) {
fetchRequest.predicate = [NSPredicate predicateWithFormat:predicateString];
}
The "proper" way to do this is with compound predicates, but this would be even more verbose.
I also noticed a possible mismatch in your example between the attribute place and your substitution variable userName. Should it be name? userPlace?
I think this is what you want:
[NSPredicate predicateWithFormat:#"(%# = \"\" OR place CONTAINS[c] %#) AND (%# = \"\" OR city CONTAINS[c] %#) AND (%# = \"\" OR state CONTAINS[c] %#) AND (%# = \"\" OR zip CONTAINS[c] %#)",
userName, userName, userCity, userCity, userState, userState, userZip, userZip];
I am trying to sort my array while using NSPredicate.. I have read other places that possibly using NSSortDescriptor could be an option. Having some trouble figuring this out.
I am attempting to sort my array by companyName.
Any advice appreciated, thanks
Greg
- (void)filterSummaries:(NSMutableArray *)all byNameThenBooth:(NSString*) text results:(NSMutableArray *)results
{
[results removeAllObjects];
if ((nil != text) && (0 < [text length])) {
if ((all != nil) && (0 < [all count])) {
NSPredicate *predicate = [NSPredicate predicateWithFormat: #"companyName contains[cd] %# OR boothNumber beginswith %#", text, text];
[results addObjectsFromArray:[all filteredArrayUsingPredicate:predicate]];
}
}
else {
[results addObjectsFromArray:all];
}
}
you have several options how to sort an array:
I'll show a NSSortDescriptor-based approach here.
NSPredicate *predicate = [NSPredicate predicateWithFormat:
#"companyName contains[cd] %# OR boothNumber beginswith %#",
text,
text];
// commented out old starting point :)
//[results addObjectsFromArray:[all filteredArrayUsingPredicate:predicate]];
// create a descriptor
// this assumes that the results are Key-Value-accessible
NSSortDescriptor *descriptor = [NSSortDescriptor sortDescriptorWithKey:#"companyName"
ascending:YES];
//
NSArray *results = [[all filteredArrayUsingPredicate:predicate]
sortedArrayUsingDescriptors:[NSArray arrayWithObject:descriptor]];
// the results var points to a NSArray object which contents are sorted ascending by companyName key
This should do your job.
The filteredArrayUsingPredicate: function walks through your array and copies all objects that match the predicate into a new array and returns it. It does not provide any sorting whatsoever. It's more of a search.
Use the sorting functions of NSArray, namely sortedArrayUsingComparator:, sortedArrayUsingDescriptors:, sortedArrayUsingFunction:context: and the like, whichever serves you most.
Checkout NSArray Class Reference for details.
BTW: If you want to sort lexically, you may use sortedArrayUsingSelector:#selector(compare:) which will use NSString's compare: function to find the right order.