Package ch.ivyteam.ivy.persistence.query

Interface IQueryExecutor<V>

Type Parameters:
V - the business object class
All Known Subinterfaces:
ICaseQueryExecutor, IIntermediateEventQueryExecutor, ITaskQueryExecutor, IUserQueryExecutor, IWorkflowEventQueryExecutor
public interface IQueryExecutor<V>
Executes a business query queries and provides different types of results (business object, result sets, count).
Since:
11.1.2012
API:
This is a public API.

  • Method Details

    • getResults

      List<V> getResults(Query<V> query)

      Gets all business objects that matches the given query.

      WARNING: This methods loads the whole resulting data set into memory.
      This can cause out of memory exceptions and bad performance of the whole engine.
      Only use this method if you are sure that the resulting data set is small. Prefer using getResults(Query, int, int), getResultsPaged(Query)

      This method considers the following parts of the query:

      • The where clauses (used to filter the business objects)
      • The orderBy clauses (used to sort the resulting list)
      This method ignores the following parts of the query:
      • The groupBy clauses
      • The aggregation (count, avg, min, max, sum) clauses

      Parameters:
      query -
      Returns:
      list of matching business objects
      See Also:
      API:
      This public API is available in Java.

    • getResults

      List<V> getResults(Query<V> query, int startIndex, int count)

      Gets all business objects that matches the given query.

      This method considers the following parts of the query:

      • The where clauses (used to filter the business objects)
      • The orderBy clauses (used to sort the resulting list)
      This method ignores the following parts of the query:
      • The groupBy clauses
      • The aggregation (count, avg, min, max, sum) clauses

      The parameters startIndex and count can be used to limit the number of objects that are returned.

      Parameters:
      query -
      startIndex - 0..n. The index of the first record is 0.
      count - 0..n. Use -1 to return all beginning from the startIndex
      Returns:
      list of matching business objects
      API:
      This public API is available in Java.

    • getResultsPaged

      IPagedResult<V> getResultsPaged(Query<V> query)

      Gets the results page wise.

      You can use this method in a for each loop to iterate over the results:

       for (V businessObject : executor.getResultsPaged(query))
 {
 System.out.println(businessObject);
 }

      You can use it to display the results in paged table on the UI:

      
 public class MyLazyDataModel extends LazyDataModel<Car> {
 @ Override
 public List<Car> load(int first, int pageSize, Map<String, SortMeta> sortMeta, Map<String, FilterMeta> filterMeta) {
 return executor.getResultsPaged(query).window(first, pageSize);
 }
 }

      This method considers the following parts of the query:

      • The where clauses (used to filter the business objects)
      • The orderBy clauses (used to sort the resulting list)
      This method ignores the following parts of the query:
      • The groupBy clauses
      • The aggregation (count, avg, min, max, sum) clauses

      You can use this method to iterate over the results by reading and loading only part of them into memory at once. This allows you to iterate over huge data sets without loading all data into memory.

      This method uses a default, system defined page size (1000) which does not harm memory and provides still good performance.

      Returns:
      paged result
      Since:
      8.0.3
      See Also:
      API:
      This public API is available in Java.

    • getResultsPaged

      IPagedResult<V> getResultsPaged(Query<V> query, int pageSize)

      Gets the results page wise.

      You can use this method in a for each loop to iterate over the results:

       for (V businessObject : executor.getResultsPaged(query, 100))
 {
 System.out.println(businessObject);
 }

      You can use it to display the results in paged table on the UI:

      
 public class MyLazyDataModel extends LazyDataModel<Car> {
 @ Override
 public List<Car> load(int first, int pageSize, Map<String, SortMeta> sortMeta, Map<String, FilterMeta> filterMeta) {
 return executor.getResultsPaged(query, pageSize).window(first, pageSize);
 }
 }

      This method considers the following parts of the query:

      • The where clauses (used to filter the business objects)
      • The orderBy clauses (used to sort the resulting list)
      This method ignores the following parts of the query:
      • The groupBy clauses
      • The aggregation (count, avg, min, max, sum) clauses

      You can use this method to iterate over the results by reading and loading only part of them into memory at once. This allows you to iterate over huge data sets without loading all data into memory.

      Parameters:
      pageSize - the maximum number of results loaded at once into memory On paged UI tables the number of objects you display on a single page.
      Returns:
      paged result
      Since:
      8.0.3
      See Also:
      API:
      This public API is available in Java.

    • getFirstResult

      V getFirstResult(Query<V> query)
      Gets the first business objects that matches the given query.

      This method considers the following parts of the query:

      • The where clauses (used to filter the business objects)
      • The orderBy clauses (used to sort the resulting list)
      This method ignores the following parts of the query:
      • The groupBy clauses
      • The aggregation (count, avg, min, max, sum) clauses

      Parameters:
      query -
      Returns:
      first business object or null if no business object matches the query
      API:
      This public API is available in Java.

    • getRecordset

      Recordset getRecordset(Query<V> query)
      Gets a Recordset with all records that matches the given query. The returned columns depend on the given query:
      • If no group by or aggregation is used, all columns of the table are returned.
      • If a group by or aggregation is used, the columns that are specified in groupBy or aggregation (count, avg, min, max, sum) are returned.
      Parameters:
      query -
      Returns:
      Recordset
      API:
      This public API is available in Java.

    • getRecordset

      Recordset getRecordset(Query<V> query, int startIndex, int count)
      Gets a Recordset with the records that matches the given query. The returned columns depend on the given query:
      • If no group by or aggregation is used, all columns of the table are returned.
      • If a group by or aggregation is used, the columns that are specified in groupBy or aggregation (count, avg, min, max, sum) are returned.

      The parameters startIndex and count can be used to limit the number of objects that are returned.

      Parameters:
      query -
      startIndex - 0..n. The index of the first record is 0.
      count - 0..n. Use -1 to return all beginning from the startIndex
      Returns:
      Recordset
      API:
      This public API is available in Java.

    • getFirstValue

      Object getFirstValue(Query<V> query)
      Gets the value of the first column and first record that matches the given query.

      The first column depends on the given query:

      • If no group by or aggregation is used, the first columns of the table is used.
      • If a group by or aggregation is used, the first columns that are specified in groupBy or aggregation (count, avg, min, max, sum) is used.

      Parameters:
      query -
      Returns:
      value of the first column and record that matches the given query. If no matching record was found null is returned.
      API:
      This public API is available in Java.

    • getCount

      long getCount(Query<V> query)
      Counts the number of rows or business objects that matches the query.

      This method considers the following parts of the query:

      • The where clauses (used to filter the business objects)
      • The groupBy clauses
      This method ignores the following parts of the query:
      • The orderBy clauses (used to sort the resulting list)
      • The aggregation (count, avg, min, max, sum) clauses

      Parameters:
      query -
      Returns:
      number of rows or business objects that matches the query
      API:
      This public API is available in Java.