public override SqlFragment Visit(DbIsNullExpression expression)
{
IsNullFragment f = new IsNullFragment();
f.Argument = expression.Argument.Accept(this);
return(f);
}
public override void Visit(DbIsNullExpression expression)
{
Check.NotNull(expression, "expression");
expression.Argument.Accept(this);
_commandText.AppendKeyword(" is null");
}
public override void Visit(DbIsNullExpression expression)
{
Write(expression);
_depth++;
Write("Argument", expression.Argument);
_depth--;
}
public override void Visit(DbIsNullExpression e)
{
Check.NotNull(e, "e");
BeginUnary(e);
End(e);
}
public override DbExpression Visit(DbIsNullExpression expression)
{
DebugCheck.NotNull(expression);
var propertyExpression
= expression.Argument as DbPropertyExpression;
if (propertyExpression != null)
{
var parameter
= GetParameter((EdmProperty)propertyExpression.Property, originalValue: true);
if (parameter != null)
{
if (parameter.Item2)
{
// Current value, remove condition
return(null);
}
var parameterReferenceExpression
= new DbParameterReferenceExpression(parameter.Item1.TypeUsage, parameter.Item1.Name);
var equalityPredicate
= propertyExpression.Equal(parameterReferenceExpression);
var nullPredicate
= propertyExpression.IsNull().And(parameterReferenceExpression.IsNull());
return(equalityPredicate.Or(nullPredicate));
}
}
return(base.Visit(expression));
}
/// <summary>
/// Evaluate a null expression.
/// </summary>
/// <param name="node">Is null expression</param>
/// <returns>A boolean expression describing the result of evaluating the Is Null predicate</returns>
public override PropagatorResult Visit(DbIsNullExpression node)
{
Debug.Assert(null != node, "node is not visited when null");
PropagatorResult argumentResult = Visit(node.Argument);
bool result = argumentResult.IsNull;
return(ConvertBoolToResult(result, argumentResult));
}
/// <summary>
/// Implements the visitor pattern for <see cref="T:System.Data.Common.CommandTrees.DbIsNullExpression"/>.
/// </summary>
/// <param name="expression">The <see cref="T:System.Data.Common.CommandTrees.DbIsNullExpression"/> that is visited.</param>
public override void Visit(DbIsNullExpression expression)
{
if (expression == null)
{
throw new ArgumentNullException("expression");
}
expression.Argument.Accept(this);
}
/// <summary>
/// Evaluate a null expression.
/// </summary>
/// <param name="node"> Is null expression </param>
/// <returns> A boolean expression describing the result of evaluating the Is Null predicate </returns>
public override PropagatorResult Visit(DbIsNullExpression node)
{
Check.NotNull(node, "node");
var argumentResult = Visit(node.Argument);
var result = argumentResult.IsNull;
return(ConvertBoolToResult(result, argumentResult));
}
/// <summary>
/// <see cref="Visit(DbIsNullExpression)"/>
/// </summary>
/// <param name="e"></param>
/// <param name="negate">Was the parent a DbNotExpression?</param>
/// <returns></returns>
private SqlBuilder VisitIsNullExpression(DbIsNullExpression e, bool negate)
{
if (!negate)
{
return(new SqlBuilder(e.Argument.Accept(this), " is null"));
}
else
{
return(new SqlBuilder(e.Argument.Accept(this), " is not null"));
}
}
public override Expression Visit(DbIsNullExpression expression)
{
Expression source = this.Visit(expression.Argument);
if (source.Type.IsValueType && !TypeHelper.IsNullable(source.Type))
{
return(Expression.Constant(false));
}
else
{
return(Expression.Equal(source, Expression.Constant(null)));
}
}
public override Expression Visit(DbIsNullExpression expression)
{
Expression source = this.Visit(expression.Argument);
if (source.Type.IsValueType && !TypeHelper.IsNullable(source.Type))
{
return Expression.Constant(false);
}
else
{
return Expression.Equal(source, Expression.Constant(null));
}
}
public override DbExpression Visit(DbIsNullExpression expression)
{
DbPropertyExpression left = expression.Argument as DbPropertyExpression;
if (left != null)
{
Tuple <FunctionParameter, bool> parameter = this.GetParameter((EdmProperty)left.Property, true);
if (parameter != null)
{
if (parameter.Item2)
{
return((DbExpression)null);
}
DbParameterReferenceExpression referenceExpression = new DbParameterReferenceExpression(parameter.Item1.TypeUsage, parameter.Item1.Name);
return((DbExpression)left.Equal((DbExpression)referenceExpression).Or((DbExpression)left.IsNull().And((DbExpression)referenceExpression.IsNull())));
}
}
return(base.Visit(expression));
}
/// <summary>
/// Visitor pattern method for <see cref="DbIsNullExpression" />.
/// </summary>
/// <param name="expression"> The DbIsNullExpression that is being visited. </param>
/// <exception cref="ArgumentNullException">
/// <paramref name="expression" />
/// is null
/// </exception>
public override void Visit(DbIsNullExpression expression)
{
VisitUnaryExpression(expression);
}
public override LegacyCommandTrees.DbExpression Visit(DbIsNullExpression expression)
{
Debug.Assert(expression != null, "expression != null");
return(expression.Argument.Accept(this).IsNull());
}
public override void Visit(DbIsNullExpression expression)
{
expression.Argument.Accept((DbExpressionVisitor)this);
this._commandText.Append(" is null");
}
public override ISqlFragment Visit(DbIsNullExpression e)
{
return(VisitIsNullExpression(e, false));
}
/// <summary> /// Visitor pattern method for DbIsNullExpression. /// </summary> /// <param name="expression"> The DbIsNullExpression that is being visited. </param> public abstract void Visit(DbIsNullExpression expression);
public override void Visit(DbIsNullExpression e)
{
Check.NotNull(e, "e");
VisitUnary(e);
}
public override void Visit(DbIsNullExpression e)
{
VisitUnary(e);
}
/// <summary> /// Typed visitor pattern method for DbIsNullExpression. /// </summary> /// <param name="expression"> The DbIsNullExpression that is being visited. </param> /// <returns> An instance of TResultType. </returns> public abstract TResultType Visit(DbIsNullExpression expression);
public override TReturn Visit(DbIsNullExpression expression)
{
Check.NotNull <DbIsNullExpression>(expression, nameof(expression));
throw this.ConstructNotSupportedException((DbExpression)expression);
}
public override void Visit(DbIsNullExpression expression)
{
// no-op
}
/// <summary> /// Visitor pattern method for DbIsNullExpression. /// </summary> /// <param name="expression"> The DbIsNullExpression that is being visited. </param> public abstract void Visit(DbIsNullExpression expression);
public override TreeNode Visit(DbIsNullExpression e)
{
Check.NotNull(e, "e");
return(VisitUnary(e));
}
public override TReturn Visit(DbIsNullExpression expression)
{
throw ConstructNotSupportedException(expression);
}
public override VfpExpression Visit(DbIsNullExpression expression)
{
return(new VfpIsNullExpression(expression.ResultType, expression.Argument.Accept(this)));
}
public override void Visit(DbIsNullExpression expression)
{
// no-op
}
public override void Visit(DbIsNullExpression expression)
{
expression.Argument.Accept(this);
_commandText.Append(" IS NULL");
}
public override DbExpressionEntitySetInfo Visit(DbIsNullExpression expression)
{
return(null);
}
public override void Visit(DbIsNullExpression e)
{
BeginUnary(e);
End(e);
}
public override TreeNode Visit(DbIsNullExpression e)
{
Check.NotNull <DbIsNullExpression>(e, nameof(e));
return(this.VisitUnary((DbUnaryExpression)e));
}
/// <summary>
/// Implements the visitor pattern for <see cref="T:System.Data.Common.CommandTrees.DbIsNullExpression"/>.
/// </summary>
/// <param name="expression">The <see cref="T:System.Data.Common.CommandTrees.DbIsNullExpression"/> that is visited.</param>
public override void Visit(DbIsNullExpression expression)
{
if (expression == null)
{
throw new ArgumentNullException("expression");
}
expression.Argument.Accept(this);
}
public override void Visit(DbIsNullExpression e)
{
VisitUnary(e);
}
public override void Visit(DbIsNullExpression e)
{
Check.NotNull <DbIsNullExpression>(e, nameof(e));
this.VisitUnary((DbUnaryExpression)e);
}
/// <summary>
/// Visitor pattern method for <see cref="DbIsNullExpression" />.
/// </summary>
/// <param name="expression"> The DbIsNullExpression that is being visited. </param>
/// <exception cref="ArgumentNullException">
/// <paramref name="expression" />
/// is null
/// </exception>
public override void Visit(DbIsNullExpression expression)
{
Check.NotNull(expression, "expression");
VisitUnaryExpression(expression);
}
public override object Visit(DbIsNullExpression expression)
{
this.Visit(expression.Argument);
return(null);
}
public override void Visit(DbIsNullExpression expression)
{
Contract.Requires(expression != null);
}
public override DbExpressionEntitySetInfo Visit(DbIsNullExpression expression)
{
Check.NotNull(expression, "expression");
return(null);
}
public override bool Visit(DbIsNullExpression expression)
{
return(VisitUnaryExpression(expression));
}
public override void Visit(DbIsNullExpression expression)
{
Check.NotNull(expression, "expression");
expression.Argument.Accept(this);
_commandText.AppendKeyword(" is null");
}
public override void Visit(DbIsNullExpression expression)
{
expression.Argument.Accept(this);
_commandText.Append(" is null");
}
public override bool Visit(DbIsNullExpression expression)
{
Check.NotNull <DbIsNullExpression>(expression, nameof(expression));
return(this.VisitUnaryExpression((DbUnaryExpression)expression));
}