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() |