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Internally used class for minimum aggregate functions
Source position: fpexprpars.pp line 656
type TAggregateMin = class(TAggregateExpr) |
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public |
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procedure InitAggregate; override; |
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Initialize minimum aggregation |
procedure UpdateAggregate; override; |
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Update minimum aggregate with new value |
end; |
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Internally used class for minimum 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 AggregateMin class implements the minimum aggregate function, which finds the smallest value among all processed values. It extends TAggregateExpr to provide minimum-specific aggregation logic.
The class maintains an internal state that tracks the minimum value encountered so far during the aggregation process. The first value encountered is used as the initial minimum, and subsequent values are compared to update the minimum when smaller values are found.
The minimum function works with numeric types (integers, floats, currency) and can also compare string and date/time values using appropriate comparison logic for each data type.
This class is used internally by the TFPExpressionParser class to construct an AST (Abstract Syntax Tree). There is normally no need for you to use or instantiate this class directly.
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Class for representing nodes in expression trees |