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155

Java FX tableview fill with an aggregated query

Dear ObjectDB, Can someone give me a tip, to make the aggregated query work. I am filling a tableview with a normal query "SELECT p From Recept p, with no problem. But when I trying to fill a tableview with an aggregated query : "SELECT SUM(getValue()) AS value ,getUnit() AS unit,getName() AS name
151

Performance issues on aggregate query

we are using this aggregate query to collect some data: select p3.doubleValue,c1.classIdentifier,c1.objectName,sum(p4.doubleValue),sum(p4.doubleValue*p5.doubleValue),0,p7.doubleValue,p3.name,count(o) from ObjectNode o INNER JOIN o.properties p1 INNER JOIN o.properties p2 INNER JOIN o.properties p3
151

Does aggregate function "greatest" work on entity objects?

Does aggregate function "greatest" work on entity objects? do not come to the function "compareTo" @Entity public class ChatHistoryItem extends AbstractObject implements Comparable { private static final long serialVersionUID = 1L; @Override public int compareTo(Object t
140

Group by: list if no aggregate function is specified

Group by: list if no aggregate function is specified
140

Problem of query With an aggregate function

Problem of query With an aggregate function
123

GROUP BY and HAVING clauses

(no Aggregates) The following query groups all the countries by their first letter: SELECT SUBSTRING(c ... : The properties that are used for grouping (each group has a unique value combination). Aggregate ... the group. The aggregate calculation gives the GROUP BY clause its power. Actually, without aggregate
43

ObjectDB Object Database Features

attributes, grouping queries and aggregate queries) which are usually missing from Object Oriented ... are indexable. Indices are also used for fast ordering and aggregate calculations. Lazy/Eager Loading ... and aggregates). ORDER BY (including ASC, DESC). Aggregates (COUNT, SUM, AVG, MAX, MIN). Query
30

Is ObjectDB better than competing object databases?

that an essential feature is missing. For example, some competing products do not support aggregate queries (max, min, count, sum and avg). ObjectDB supports rich queries, including aggregate queries
30

Running JPA Queries

when exactly one result object is expected. The following aggregate query always returns a single result ... Country c"); long countryCount = (Long)query.getSingleResult(); An aggregate COUNT query
29

javax.persistence.criteria.CriteriaBuilder

.0 Expression<Double> avg( Expression<N> x) Create an aggregate expression applying the avg operation. Create an aggregate expression applying the avg operation. Parameters: x - expression representing ... item Since: JPA 2.0 Expression<Long> count( Expression<?> x) Create an aggregate expression applying

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Prior knowledge or experience in database programming (SQL, JDBC, ORM, JPA, etc.) is not required, but some background in using the Java language is essential.

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