PFQuery with multiple constraints on one key

Question

i have parse.com database. i have column in a table named "text". i have to find text with multiple keys matching with AND condition. i tried it all ways. i tried to use:

    PFQuery *query=[PFQuery queryWithClassName:@"post"];
    [query whereKey:@"text" containedIn:Array];

or

    PFQuery *query=[PFQuery queryWithClassName:@"post"];
    [query whereKey:@"text" containsAllObjectsInArray:Array];        

or

PFQuery *query=[PFQuery queryWithClassName:@"post"];
for (NSString *str in filtersArray) {

    [query whereKey:@"text" containsString:str];

}

but no one works. please guide me if parse sdks supports this or not totally? if yes how can i achieve the results. many thanks in advance :)

EIDT:

for example i have three entries in database as text:

1. "i have a data entry"

2. "i can not find something in data"

3. "how can i do this"

if pass "i" and "this" it should return entry (3)

if pass "i" and "data" it should return entry (1,2)

if pass "i" and "else" it should return nothing

Answer 1

The reason your query doesn't work is because Parse does not support having the same constraint (in this case 'containsString:') more than once on the same key.

So, what I would suggest is to query for a regular expression which will match all of your filter strings using - (instancetype)whereKey:(NSString *)key matchesRegex:(NSString *)regex.

NSArray *qryStrings = @[str1, str2, str3, ....]; //strings you are trying to match

//string which will hold our regular expression
NSString *regexString = @"^"; //start off the regex

for (NSString *str in qryStrings) { //build the regex one filter at a time
    regexString = [NSString stringWithFormat:@"%@(?=.*%@)", regexString, str];
}

regexString = [NSString stringWithFormat:@"%@.*$", regexString]; //finish off the regex

PFQuery *query = [PFQuery queryWithClassName:@"post"];
[query whereKey:@"text" matchesRegex:regexString];
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
    if (!error) {
        //objects array contains matching rows with matching strings
    }
    else {
        NSLog(@"%@ %@", error, [error userInfo]);
    }
}];

Answer 2

Depending on the speed requirements of your query and the number of objects being queried, I would try separating the results using componentsSeparatedByString: after enumerating through the results array using something like: for(NSString *string in results). After separating each string into an individual array, use an if(...) statement that determines if that collection of words contains each word searched.

Code example:

NSMutableArray *searchResults = [[NSMutableArray alloc] init];
PFQuery *query=[PFQuery queryWithClassName:@"post"];

// consider setting a limit, depending on the number of posts
// consider sorting the query as needed

NSArray *posts = [query findObjects];
for(NSString *text in posts)           
{
  NSArray *words = [text componentsSeparatedByString:@" "];   // use SeperatedByCharactersInSet: for . , or anything else you'd need
  switch ([filterArray count])
  {
    case 1:
      if([words containsObject:filterArray[0]])
      {
         [searchResults addObject:text];
      } 

      break;

    case 2:
      if([words containsObject:filterArray[0]] && 
         [words containsObject:filterArray[1]])
      {
         [searchResults addObject:text];
      } 

      break;

    // case n:
    //   if([words containsObject:filterArray[0]] && 
    //      [words containsObject:filterArray[1]] &&
    //      [words containsObject:filterArray[n]])
    //   {
    //      [searchResults addObject:text];
    //   } 
    //
    //   break;

    default:
      break;
  }

 _filteredResults = [NSArray arrayWithArray:searchResults]; // local global instance of results - use for maintaining order (be sure to clear it between searches)

The _filteredResults array should be what you're wanting. Be sure to consider speed and the character separators used in the search though.

Answer 3

You simply just need to use whereKey:containsString:

And if you want to use additional parameters, you just simply add a subQuery

Answer 4

Your solution need to modify a bit.

Like this.

PFQuery *query=[PFQuery queryWithClassName:@"post"];
[query whereKey:@"text" containedIn:Array];
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
//what your logic you want to write there might comes some records that are counts two times so you can remove those using NSSet
 }];