Updated query docs in API ref to reflect the features of the new query parser

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astigsen 2018-02-27 14:30:31 -08:00
parent 4bc69f0a1b
commit 76acf0ab60
1 changed files with 55 additions and 3 deletions

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@ -23,7 +23,7 @@ let merlots = wines.filtered('variety == $0 && vintage <= $1', 'Merlot', maxYear
``` ```
### Relational operators ### Conditional operators
You can use equality comparison on all property types: You can use equality comparison on all property types:
`==` and `!=` `==` and `!=`
@ -35,7 +35,7 @@ Example:
let oldContacts = realm.objects('Contact').filtered('age > 2'); let oldContacts = realm.objects('Contact').filtered('age > 2');
``` ```
Note that for boolean properties, you should test against the expected keyword. Note that for boolean properties, you should test against `true` or `false`.
Example: Example:
```JS ```JS
@ -43,7 +43,7 @@ let women = realm.objects('Contact').filtered('isMale == false');
``` ```
### String operators ### String operators
For string properties, prefix, suffix, and substring queries are supported by using the `BEGINSWITH`, `ENDSWITH`, and `CONTAINS` operators. For string properties, prefix, suffix, and substring queries are supported by using the `BEGINSWITH`, `ENDSWITH`, `CONTAINS` and `LIKE` operators.
For any string operation you can append `[c]` to the operator to make it case insensitive. For any string operation you can append `[c]` to the operator to make it case insensitive.
@ -53,6 +53,58 @@ let peopleWhoseNameContainsA = realm.objects('Contact').filtered('name CONTAINS[
let Johns = realm.objects('Contact').filtered('name ==[c] "john"'); let Johns = realm.objects('Contact').filtered('name ==[c] "john"');
``` ```
You can do simple wildcard matching with `LIKE` which supports using `?` to match a single character and `*` to match zero or multiple characters.
Example:
```JS
// Matches "John" and "Johnny"
let Johns = realm.objects('Contact').filtered('name LIKE "John*"');
```
### Composition ### Composition
Use parentheses and the `&&`/`AND` and `||`/`OR` operators to compose queries. You can negate a predicate with `!`/`NOT`. Use parentheses and the `&&`/`AND` and `||`/`OR` operators to compose queries. You can negate a predicate with `!`/`NOT`.
### Queries on collections
When objects contain lists you can query into them using the collection operators `ANY`, `ALL` and `NONE`.
Example:
```JS
// Find contacts with one or more teenage friends
let teens = realm.objects('Contact').filtered('ANY friends.age < 14');
// Find contacts where all friends are older than 21
let adults = realm.objects('Contact').filtered('ALL friends.age > 21');
```
You can query on aggregates over properties in the lists using the aggregate operators `.@count`, `.@avg`, `.@min`, `.@max` and `.@sum`.
Example:
```JS
// Find contacts without friends
let teens = realm.objects('Contact').filtered('friends.@count == 0');
// Find contacts where the average age of their friends is above 40
let adults = realm.objects('Contact').filtered('friends.@avg.age > 40"');
```
Subqueries using the `SUBQUERY` operator allows you to filter the lists across multiple parameters while querying them.
Example:
```JS
// Find contacts with friends above 21 in SF
let teens = realm.objects('Contact').filtered('SUBQUERY(friends, $friend, $friend.age > 21 AND $friend.city = 'SF').@count > 0');
```
### Backlink queries
Other objects can link to an object and you can query on that releationship using the `@links` and `@links.ClassName.PropertyName` syntax:
Example:
```JS
// Find contacts with no incomming links
let lonely = realm.objects('Contact').filtered('@links.@count == 0);
// Find contacts where someone from SF has them as friends
realm.objects('Contact').filtered('@links.Contact.friends.city == "SF");
```