TSqlExpression
Base class for expressions in an SQL expression tree.
Inheritance
Level | Ancestor | Description |
---|---|---|
1 | TObject | Ultimate ancestor in a class hierarchy |
2 | TBaseObject | A base class for objects that can be used instead of TObject . |
3 | TReferenceCountedObject | Object that keeps track of the number of times it is referenced from other objects |
4 | TSqlExpression |
Source
Sql.Expression.pas (27)
Description
Every descendant should provide a correct implementation of Copy
using the following specific pattern. Every descendant introduces a
new (virtual) function named Copy<DescendantName>()
in which the actual copying is implemented. The copy function should create a
deep copy. Then the descendant overrides the function Copy<ParentName>()
by delegating it to
Copy<DescendantName>()
. Using this pattern SQL expressions can be copied in a type safe way even for descendant classes.
Methods
Scope | Visibility | Result | Name | Description |
---|---|---|---|---|
Instance | public | TType | GetType() | |
Instance | public | TSqlExpression | Copy() | |
Instance | public | TBoolean | IsSimpleOperand() | |
Instance | public | TBoolean | AggregatesRows() | |
Global | public | Create() | ||
Global | public | Destroy() |