Details
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New Feature
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Status: Closed
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Major
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Resolution: Fixed
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None
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None
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None
Description
Ⅰ. Introduction
GINQ DSL is an alternative solution of GINQ, it is a simplified version of GINQ(GROOVY-9159) and will be implemented as a module "groovy-ginq".
GINQ DSL is wrapped with:
GQ {
// GINQ code
}
NOTE:
- The simplest GINQ MUST consist of ONE from clause and ONE select clause, which looks like:
from n in [1, 2, 3] select n
- Currently supports the following clauses:
ginq
|__ from
|__ [innerjoin/leftjoin/rightjoin/fulljoin/crossjoin]*
| |__ on
|__ [where]
|__ [groupby]
| |__ [having]
|__ [orderby]
|__ [limit]
|__ select
(Note: [ ] means optional)
Ⅱ. Sample code related to GROOVY-9159
1. Filtering
1.1
from p in persons where p.age > 15 && p.age <= 35 select p.name
1.2
from p in persons where p.age > 15 && p.age <= 35 select p
1.3
from t in numbers where t <= 2 select t
2. Joining
2.1
from p in persons
innerjoin c in cities on p.city.name == c.name // putting `on` clause in the same line with `innerjoin` is recommended code style
select p.name, c.name
2.2
from p in persons innerjoin c in cities on p.city == c select p.name
2.3
from p in persons
leftjoin c in cities on p.city.name == c.name // same with left outer join
select p.name, c.name
2.4
from p in persons
rightjoin c in cities on p.city.name == c.name // same with right outer join
select p.name, c.name
3. Projection
3.1
from p in persons select p.name
3.2
from p in persons select p.name, p.age
3.3
from p in persons select [name: p.name, age: p.age]
3.4
from p in persons
select new Person(name: p.name, age: p.age)
3.5
from p in persons select p
4. Grouping
4.1
from p in persons groupby p.gender select p.gender, max(p.age)
5. Having
5.1
from p in persons
groupby p.gender
having p.gender == 'Male'
select p.gender, max(p.age)
6. Sorting
6.1
from p in persons orderby p.age select p.name
6.2
from p in persons
orderby p.age in desc // "`in` order" means sorting
select p.name
6.3
from p in persons
orderby p.age in desc, p.name in asc // asc is optional
select p.name
7. Pagination
7.1
from n in numbers limit 2, 5 select n
7.2
from n in numbers limit 5 select n
8. Nested Queries
8.1
from v in (
from n in numbers
where n <= 5
select n
)
limit 2, 5
select v
Advanced cases could be found at GROOVY-9806
Attachments
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