Class UnionExpression

UnionExpressions contain ColumnReferences in the tables that feed a Union that should map to the same Expression in the Union. A UNION operation combines rows from different tables that all have same schema. The expressions in a Union table are pointers to the individual columnReferences that are unioned together in a particular column.

Inheritance
Object
Expression
Expression<UnionExpression, Union>
UnionExpression
Inherited Members
Namespace: Mangrove.MetricSetSyntaxTree.ExpressionNodes
Assembly: MetricSetSyntaxTree.dll
Syntax
public class UnionExpression : Expression<UnionExpression, Union>, IVisitable<IExpressionVisitor>, ICloneable<UnionExpression, Union, Expression>, ICloneable<Expression>, IDirectedAcyclicGraph<Expression>

Constructors

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UnionExpression(Union, IReadOnlyList<ColumnReference>)

Declaration
public UnionExpression(Union table, IReadOnlyList<ColumnReference> columnReferences)
Parameters
Type Name Description
Union table
IReadOnlyList<ColumnReference> columnReferences

Properties

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ColumnReferences

List of references from tables that feed the Union.

Declaration
public IReadOnlyList<ColumnReference> ColumnReferences { get; }
Property Value
Type Description
IReadOnlyList<ColumnReference>
Remarks

Generally, a well-formed UnionExpression will have exactly one ColumnReference in each of the tables that feeds the Union table.

No validation for this requirement is provided in this class.

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Parents

Declaration
[JsonIgnore]
public override IReadOnlyList<Expression> Parents { get; }
Property Value
Type Description
IReadOnlyList<Expression>
Overrides

Methods

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Accept(IExpressionVisitor)

Declaration
public override void Accept(IExpressionVisitor visitor)
Parameters
Type Name Description
IExpressionVisitor visitor
Overrides
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Clone(Union, IReadOnlyList<Expression>)

Declaration
public override UnionExpression Clone(Union table, IReadOnlyList<Expression> parents)
Parameters
Type Name Description
Union table
IReadOnlyList<Expression> parents
Returns
Type Description
UnionExpression
Overrides
Mangrove.MetricSetSyntaxTree.Expression<Mangrove.MetricSetSyntaxTree.ExpressionNodes.UnionExpression, Mangrove.MetricSetSyntaxTree.TableNodes.Union>.Clone(Mangrove.MetricSetSyntaxTree.TableNodes.Union, System.Collections.Generic.IReadOnlyList<Mangrove.MetricSetSyntaxTree.Expression>)

Implements

Extension Methods