[Properties (by Name)] [Methods (by Name)] [Events (by Name)]
Internally used class for count aggregate functions
Source position: fpexprpars.pp line 696
type TAggregateCount = class(TAggregateExpr) |
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public |
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procedure InitAggregate; override; |
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Initialize count aggregation |
procedure UpdateAggregate; override; |
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Update count aggregate with new value |
end; |
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Internally used class for count aggregate functions |
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Internally used Base class for aggregate expressions |
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Internally used class for representing function calls in expression trees |
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Internally used class for identifier nodes in expression trees |
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Class for representing nodes in expression trees |
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The TAggregateCount class implements the count aggregate function, which counts the number of values processed during aggregation. It extends TAggregateExpr to provide count-specific aggregation logic.
Unlike other aggregate functions that process the actual values, the count function simply increments a counter for each value encountered, regardless of the value's content or type. This makes it useful for determining the number of records or values in a dataset.
The count function always returns an integer result representing the total number of values processed during the aggregation cycle.
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Class for representing nodes in expression trees |