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using System;
using System.Collections.ObjectModel;
using System.Text;
namespace System.Data.Linq.SqlClient {
/// <summary>
/// Methods for checking whethe a query was compatible with the
/// server it will be sent to.
/// </summary>
static internal class SqlServerCompatibilityCheck {
/// <summary>
/// Private visitor class checks each node for compatibility annotations.
/// </summary>
private class Visitor : SqlVisitor {
private SqlProvider.ProviderMode provider;
internal SqlNodeAnnotations annotations;
internal Visitor(SqlProvider.ProviderMode provider) {
this.provider = provider;
}
/// <summary>
/// The reasons why this query is not 2K compatible.
/// </summary>
internal Collection<string> reasons = new Collection<string>();
internal override SqlNode Visit(SqlNode node) {
if (annotations.NodeIsAnnotated(node)) {
foreach (SqlNodeAnnotation annotation in annotations.Get(node)) {
SqlServerCompatibilityAnnotation ssca = annotation as SqlServerCompatibilityAnnotation;
if (ssca != null && ssca.AppliesTo(provider)) {
reasons.Add(annotation.Message);
}
}
}
return base.Visit(node);
}
}
/// <summary>
/// Checks whether the given node is supported on the given server.
/// </summary>
internal static void ThrowIfUnsupported(SqlNode node, SqlNodeAnnotations annotations, SqlProvider.ProviderMode provider) {
// Check to see whether there's at least one SqlServerCompatibilityAnnotation.
if (annotations.HasAnnotationType(typeof(SqlServerCompatibilityAnnotation))) {
Visitor visitor = new Visitor(provider);
visitor.annotations = annotations;
visitor.Visit(node);
// If any messages were recorded, then throw an exception.
if (visitor.reasons.Count > 0) {
throw Error.ExpressionNotSupportedForSqlServerVersion(visitor.reasons);
}
}
}
}
}
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