From apple doc:
These two predicates give me same result:
Uppercased SELF:
NSPredicate *predicate = [NSPredicate predicateWithFormat: #"SELF.userType != %#", typeStr];
Lowecased SELF:
NSPredicate *predicate = [NSPredicate predicateWithFormat: #"self.userType != %#", typeStr];
Are Reserved Words case sensitive?
See Predicate Format String Syntax
"The predicate string parser is whitespace insensitive, case insensitive with respect to keywords, and supports nested parenthetical expressions."
Related
In my app I allow users to search for vehicles by make/model using a textfield keyword search. Here is my predicate:
if (self.keywordSearch.text.length > 0) {
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"fields.make CONTAINS[cd] %# OR fields.model CONTAINS[cd] %#", self.keywordSearch.text, self.keywordSearch.text];
self.vehicleArray = [[self.vehicleArray filteredArrayUsingPredicate:predicate] mutableCopy];
}
The problem is that if the Vehicle make/model is 'Ford F-150' and the user searches F150, or F 150, the vehicle isn't included in the results. It only returns if they search F-150 or f-150.
Is there a way to make sure these inexact matches are returning?
I suggest using regular expressions for this. You can either use a regular expression literal inside the NSPredicate format (described here: https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/Predicates/Articles/pUsing.html ) or you can iterate the array manually and use an NSRegularExpression for comparing the strings.
I try to express the search parameters with predicate:
NSPredicate *predicate=[NSPredicate predicateWithFormat:#"name CONTAINS [cd] %# OR code CONTAINS [cd] %# OR currency CONTAINS [cd] %# AND continent.paid == %#",searchString,searchString,searchString,[NSNumber numberWithBool:YES]];
I try to express search parameters for possible string records ONLY where continent.paid==YES. The problem is that last expression is ignored. The search returns data from continent.paid==NO as well with the correct data. Whats wrong with it?
You have to set parentheses:
[NSPredicate predicateWithFormat:#"(name CONTAINS [cd] %# OR code CONTAINS [cd] %# OR currency CONTAINS [cd] %#) AND continent.paid == %#",
searchString,searchString,searchString,[NSNumber numberWithBool:YES]];
As far as I know, "AND" and "OR" have the same precedence in a predicate, and are evaluated
from left to right. Therefore in your code, the predicate evaluates to true if one
of the "CONTAINS" expressions is true.
I use this predicate:
NSPredicate *offencePredicate =
[NSPredicate predicateWithFormat:#"(%# == %#) AND (%# == %d)", kTeamID, self.selectedTeam.teamID, kPlayerZoneID, ZoneIdTypeOffence];
but the predicate is:
"teamID" == 10 AND "playerZoneID" == 3
instead of:
teamID == 10 AND playerZoneID == 3
How can I trim this "" when I use format specifiers for predicating. And the next question is: is this the right solution using form specifiers in predicate. Because I have some API keys that are correspond to my core data entries attributes. So it is ok to use constant string that will allow quite faster changes if I need to change some of these keys, but is it ok to use this constant for predication?
You need to use %K for the keys.
It would look like this:
[NSPredicate predicateWithFormat:#"(%K == %#) AND (%K == %d)", kTeamID, self.selectedTeam.teamID, kPlayerZoneID, ZoneIdTypeOffence];
Use %K.
See this example from the documentation:
NSString *attributeName = #"firstName";
NSString *attributeValue = #"Adam";
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"%K like %#",
attributeName, attributeValue];
Result:
firstName like "Adam"
I am using NSPredicate for the performing Search as it does on iPhone when we search for any app.
I have say for example 4 keywords
Deccan
New Delhi
Ahmedabad
Salaam Delhi
I have tried creating a predicate with
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"keyword BEGINSWITH[c] 'd'"
It gives me Deccan as output.
But the problem is I want each word starting with d So from the above example I need output as
Deccan, New Delhi, Salaam Delhi but NOT Ahmedabad
Stucked in this issue from hours. tried contains, matches but my bad luck..
Any help towards right path will really be appreciated..
Thanks guys for your responses
Here's what I come up with
NSString *matchString = [NSString stringWithFormat: #".*\\b%#.*",searchText];
NSString *predicateString = #"keyword MATCHES[c] %#";
NSPredicate *predicate =[NSPredicate predicateWithFormat: predicateString, matchString];
There are two way for you
Divide the steing by ' ' and use your NSPredicate *predicate = [NSPredicate predicateWithFormat:#"keyword BEGINSWITH[c] 'd'"]
Or, the better way, to use two predicates :
predicate = [NSPredicate predicateWithFormat:#"keyword BEGINSWITH[c] 'd'
OR keyword contains[c] ' d'"]// i mean,'space+d'
So you'll it will satisfy both of possible cases.
Consider "like" and "matches." Note, however, that these are relatively expensive operations, and can take considerable time on large data sets.
In this example, I assume what you want is to match if any space-separated word in starts with "d"
This checks to see if keyword either begins with 'd' or has a sequence with a followed by 'd'
[NSPredicate predicateWithFormat:#"(keyword BEGINSWITH[c] 'd') OR (keyword LIKE[c] '* d')"]
This one uses a regular expression, which is very similar (use the regex that best suites your situation:
[NSPredicate predicateWithFormat:#"keyword MATCHES[c] '^d.*|.*\\sd.*'"]
I have 2 entities with a one to many relationship. Category represents my section headers and SubSubCategory represents my rows.
Category
{
name:string
subs<-->>SubCategory
}
SubCategory
{
name:string
numbervalue:NSNumber
}
Currently I can use NSPredicate to filter my sections based on name.
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"name==%#",#"anamevalue"];
Now I want to further filter this predicate to only return categories that have a Subcategory with a subvalue == 1.
How can I filter the Category entity based on the values in its one to many children?
I tried something like this but its no good.
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"name==%# AND subs.numbervalue==%#",#"anamevalue",1];
I'll do a predicate like the following:
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"name == %# AND ANY subs.numbervalue == %#)", #"anamevalue", [NSNumber numberWithInt:1]];
The ANY is a predicate modifier that returns true only if there is at least one object in subs collection for which the comparison returns true.
The same result could be done by means of SUBQUERY.
Hope it helps.
The syntax in your predicate is wrong. You are passing an integer value as a string.
Your predicate should be
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"name==%# AND subs.numbervalue==%i",#"anamevalue",1]
Other than that it looks correct.