# Class NpgsqlSetOperationTypingInjector

Namespace
  Npgsql.EntityFrameworkCore.PostgreSQL.Query.Internal

Assembly
  Npgsql.EntityFrameworkCore.PostgreSQL.dll

A visitor that injects explicit typing on null projections in set operations, to ensure PostgreSQL gets the typing right.

    public class NpgsqlSetOperationTypingInjector : ExpressionVisitor

Inheritance
  object
  ExpressionVisitor
  NpgsqlSetOperationTypingInjector

Inherited Members
  ExpressionVisitor.Visit(ReadOnlyCollection<Expression>)
  ExpressionVisitor.Visit(Expression)
  ExpressionVisitor.VisitAndConvert<T>(ReadOnlyCollection<T>, string)
  ExpressionVisitor.VisitAndConvert<T>(T, string)
  ExpressionVisitor.VisitBinary(BinaryExpression)
  ExpressionVisitor.VisitBlock(BlockExpression)
  ExpressionVisitor.VisitCatchBlock(CatchBlock)
  ExpressionVisitor.VisitConditional(ConditionalExpression)
  ExpressionVisitor.VisitConstant(ConstantExpression)
  ExpressionVisitor.VisitDebugInfo(DebugInfoExpression)
  ExpressionVisitor.VisitDefault(DefaultExpression)
  ExpressionVisitor.VisitDynamic(DynamicExpression)
  ExpressionVisitor.VisitElementInit(ElementInit)
  ExpressionVisitor.VisitGoto(GotoExpression)
  ExpressionVisitor.VisitIndex(IndexExpression)
  ExpressionVisitor.VisitInvocation(InvocationExpression)
  ExpressionVisitor.VisitLabel(LabelExpression)
  ExpressionVisitor.VisitLabelTarget(LabelTarget)
  ExpressionVisitor.VisitLambda<T>(Expression<T>)
  ExpressionVisitor.VisitListInit(ListInitExpression)
  ExpressionVisitor.VisitLoop(LoopExpression)
  ExpressionVisitor.VisitMember(MemberExpression)
  ExpressionVisitor.VisitMemberAssignment(MemberAssignment)
  ExpressionVisitor.VisitMemberBinding(MemberBinding)
  ExpressionVisitor.VisitMemberInit(MemberInitExpression)
  ExpressionVisitor.VisitMemberListBinding(MemberListBinding)
  ExpressionVisitor.VisitMemberMemberBinding(MemberMemberBinding)
  ExpressionVisitor.VisitMethodCall(MethodCallExpression)
  ExpressionVisitor.VisitNew(NewExpression)
  ExpressionVisitor.VisitNewArray(NewArrayExpression)
  ExpressionVisitor.VisitParameter(ParameterExpression)
  ExpressionVisitor.VisitRuntimeVariables(RuntimeVariablesExpression)
  ExpressionVisitor.VisitSwitch(SwitchExpression)
  ExpressionVisitor.VisitSwitchCase(SwitchCase)
  ExpressionVisitor.VisitTry(TryExpression)
  ExpressionVisitor.VisitTypeBinary(TypeBinaryExpression)
  ExpressionVisitor.VisitUnary(UnaryExpression)
  ExpressionVisitor.Visit<T>(ReadOnlyCollection<T>, Func<T, T>)
  object.Equals(object)
  object.Equals(object, object)
  object.GetHashCode()
  object.GetType()
  object.MemberwiseClone()
  object.ReferenceEquals(object, object)
  object.ToString()

## Remarks

See the PostgreSQL docs on type conversion and set operations.

This is an internal API that supports the Entity Framework Core infrastructure and not subject to the same compatibility standards as public APIs. It may be changed or removed without notice in any release. You should only use it directly in your code with extreme caution and knowing that doing so can result in application failures when updating to a new Entity Framework Core release.

## Methods

### VisitExtension(Expression)

This is an internal API that supports the Entity Framework Core infrastructure and not subject to the same compatibility standards as public APIs. It may be changed or removed without notice in any release. You should only use it directly in your code with extreme caution and knowing that doing so can result in application failures when updating to a new Entity Framework Core release.

    protected override Expression VisitExtension(Expression extensionExpression)

#### Parameters

`extensionExpression` Expression

#### Returns

Expression