public static IExpression Where(this IStatement statment, ICondition criteria)
{
if (criteria == null)
{
return(null);
}
if (criteria is Condition c)
{
return(ConditionExtension.ToExpression(c, field => From(statment, field, out var property).CreateField(property), parameter => statment.Parameters.Add(parameter)));
}
if (criteria is ConditionCollection cc)
{
return(ConditionExtension.ToExpression(cc, field => From(statment, field, out var property).CreateField(property), parameter => statment.Parameters.Add(parameter)));
}
throw new NotSupportedException($"The '{criteria.GetType().FullName}' type is an unsupported condition type.");
}
public static IExpression Where(this IStatement statement, ICondition criteria)
{
if(criteria == null)
return null;
if(criteria is Condition c)
return ConditionExtension.ToExpression(c,
field => GetField(statement, field),
parameter => statement.Parameters.Add(parameter));
if(criteria is ConditionCollection cc)
return ConditionExtension.ToExpression(cc,
field => GetField(statement, field),
parameter => statement.Parameters.Add(parameter));
throw new NotSupportedException($"The '{criteria.GetType().FullName}' type is an unsupported condition type.");
FieldIdentifier GetField(IStatement host, Condition condition)
{
var source = From(statement, condition.Name, (src, complex) => CreateSubquery(host, src, complex, condition.Value as ICondition), out var property);
if(property.IsSimplex)
return source.CreateField(property);
if(condition.Operator == ConditionOperator.Exists || condition.Operator == ConditionOperator.NotExists)
{
condition.Value = source;
return null;
}
throw new DataException($"The specified '{condition.Name}' condition is associated with a one-to-many composite(navigation) property and does not support the {condition.Operator} operation.");
}
ISource CreateSubquery(IStatement host, ISource source, IDataEntityComplexProperty complex, ICondition condition)
{
var subquery = host.Subquery(complex.Foreign);
var where = ConditionExpression.And();
foreach(var link in complex.Links)
{
subquery.Select.Members.Add(subquery.Table.CreateField(link.Foreign));
where.Add(Expression.Equal(
subquery.Table.CreateField(link.Foreign),
source.CreateField(link.Principal)
));
}
if(complex.HasConstraints())
{
foreach(var constraint in complex.Constraints)
{
where.Add(Expression.Equal(
subquery.Table.CreateField(constraint.Name),
complex.GetConstraintValue(constraint)
));
}
}
if(condition != null)
where.Add(Where(subquery, condition));
subquery.Where = where;
return subquery;
}
}