[CAY-2209] Shortcuts for aggregate functions

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Component/s: Core Library
• Assignee: Nikita Timofeev
• Reporter: Nikita Timofeev
• Created: 24/Jan/17 09:07
• Updated: 25/Jan/17 14:22
• Resolved: 25/Jan/17 14:22

Description

1. new methods in ObjectSelect and ColumnSelect
   • min
   • max
   • avg
   • sum
   • count
2. new methods in Property class
   • min
   • max
   • avg
   • sum
   • count
   • plus constant Property.COUNT
3. ColumnSelect can be created only via ObjectSelect (methods columnQuery(...))

// Select COUNT(*) examples:
long count = ObjectSelect
        .columnQuery(Artist.class, Property.COUNT) // constant property
        .selectOne(context);

long count2 = ObjectSelect
        .query(Artist.class)
        .count()
        .selectOne(context);

long count3 = ObjectSelect
        .query(Artist.class)
        .selectCount(context); //  new select*() method

// Select COUNT(attributes) examples:
long count2 = ObjectSelect
        .columnQuery(Artist.class, Artist.DATE_OF_BIRTH.count()) // new methods in Property class
        .selectOne(context);

long count3 = ObjectSelect
        .query(Artist.class)
        .count(Artist.DATE_OF_BIRTH)
        .selectOne(context);

// All aggregates:
Property<BigDecimal> estimatedPrice = Artist.PAINTING_ARRAY.dot(Painting.ESTIMATED_PRICE);
Object[] minMaxAvgSumCount = ObjectSelect.query(Artist.class)
        .where(estimatedPrice.gte(min))
        .min(estimatedPrice)
        .max(estimatedPrice)
        .avg(estimatedPrice)
        .sum(estimatedPrice)
        .count()
        .selectOne(context);