org.sormula.operation.aggregate
Class SelectCountOperation<R,T>

java.lang.Object
  org.sormula.operation.SqlOperation<R>
      org.sormula.operation.ScalarSelectOperation<R>
          org.sormula.operation.aggregate.SelectAggregateOperation<R,T>
              org.sormula.operation.aggregate.SelectCountOperation<R,T>

Type Parameters:

R - class type which contains members for columns of a row in a table

T - class type of aggregate result

public class SelectCountOperation<R,T>
extends SelectAggregateOperation<R,T>

SQL COUNT aggregate operation. See base class for details about use.

The data type returned from database is the same type as the expression. For example, if expression is a column, then the returned type is the same type as column. If expression is "*", then databases typically return a long.

Since:

1.1

Author:

Jeff Miller

Constructor Summary

SelectCountOperation(Table<R> table, java.lang.String expression)
Constructs for standard sql select statement as:
SELECT COUNT(e), ...

Method Summary

Methods inherited from class org.sormula.operation.aggregate.SelectAggregateOperation

initBaseSql, readAggregate

Methods inherited from class org.sormula.operation.ScalarSelectOperation

close, execute, getMaximumRowsRead, getOrderByName, getOrderByTranslator, getResultSet, getRowsReadCount, getSql, isLazySelectsCascades, isNotifyLazySelects, postRead, postReadCascade, prepareCascades, preRead, preReadCascade, readNext, select, select, setMaximumRowsRead, setOrderBy, setOrderByTranslator, setParameters, setRowParameters

Methods inherited from class org.sormula.operation.SqlOperation

cancel, cascade, closeCascades, closeStatement, createTargetField, getBaseSql, getConnection, getCustomSql, getNextParameter, getOperationTime, getParameters, getPreparedSql, getPreparedStatement, getQueryTimeout, getTable, getTargetTable, getTimingId, getWhereConditionName, getWhereTranslator, initOperationTime, isAutoGeneratedKeys, isIncludeIdentityColumns, isReadOnly, isTimings, logTimings, prepare, prepareCascades, prepareCheck, prepareColumns, prepareParameters, prepareWhere, setAutoGeneratedKeys, setBaseSql, setCustomSql, setIncludeIdentityColumns, setNextParameter, setQueryTimeout, setReadOnly, setTimingId, setTimings, setWhere, setWhereTranslator, writeColumns, writeParameter, writeParameters, writeWhere

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SelectCountOperation

public SelectCountOperation(Table<R> table,
                            java.lang.String expression)
                     throws OperationException

Constructs for standard sql select statement as:
SELECT COUNT(e), ... FROM table
where e is a SQL expression (typically a column name).

Parameters:

table - select from this table

expression - expression to use as parameter to function; typically it is the name of a column to that aggregate function operates upon (example: COUNT(amount) amount is expression)

Throws:

OperationException - if error