ExecutionEngineException thrown when mapping with IDataReader to DTO with a different datatype for a property

[automapper]

ExecutionEngineException thrown when mapping with IDataReader to DTO with a different datatype for a property

[jumas45]

@jbogard Issue still exists. Is this going to be fixed in version 4.1?

[jbogard]

From @rlaveycal on February 14, 2014 12:36

The problem still exists in version 3.1.1.

It seems to be caused by the IL generated by DataReaderMapper.CreateBuilder(). This enumerates all the columns of the data reader and assigns the value to the corresponding property on the destination type, with no type checking. In cases where the types don't match there should be an override defined as part of the map definition by calling ForMember() so there is no need to attempt the assignment. My solution below uses this assumption to short circuit the IL generation

First add a parameter to CreateBuilder and build a map of the properties that we don't need to assign

        private static Build CreateBuilder(Type destinationType, IDataRecord dataRecord, IEnumerable<PropertyMap> propertyMaps)
        {
            Build builder;
            BuilderKey builderKey = new BuilderKey(destinationType, dataRecord);
            if (_builderCache.TryGetValue(builderKey, out builder))
            {
                return builder;
            }

            HashSet<string> overriddenProperties = new HashSet<string>();
            foreach (var map in propertyMaps)
            {
                overriddenProperties.Add(map.DestinationProperty.Name);
            }

Then, check each property in the loop - we can share GetName(i) via a variable.

            for (var i = 0; i < dataRecord.FieldCount; i++)
            {
                string name = dataRecord.GetName(i);
                if(overriddenProperties.Contains(name))
                    continue;

Finally the calls to CreateBuilder() need to have the extra parameter supplied - context.GetContextTypeMap().GetPropertyMaps()

[jbogard]

Cool, I'll get this in 3.2

On Fri, Feb 14, 2014 at 6:36 AM, rlaveycal [email protected] wrote:

The problem still exists in version 3.1.1.

It seems to be caused by the IL generated by
DataReaderMapper.CreateBuilder(). This enumerates all the columns of the
data reader and assigns the value to the corresponding property on the
destination type, with no type checking. In cases where the types don't
match there should be an override defined as part of the map definition by
calling ForMember() so there is no need to attempt the assignment. My
solution below uses this assumption to short circuit the IL generation

First add a parameter to CreateBuilder and build a map of the properties
that we don't need to assign

    private static Build CreateBuilder(Type destinationType, IDataRecord dataRecord, IEnumerable<PropertyMap> propertyMaps)
    {
        Build builder;
        BuilderKey builderKey = new BuilderKey(destinationType, dataRecord);
        if (_builderCache.TryGetValue(builderKey, out builder))
        {
            return builder;
        }

        HashSet<string> overriddenProperties = new HashSet<string>();
        foreach (var map in propertyMaps)
        {
            overriddenProperties.Add(map.DestinationProperty.Name);
        }

Then, check each property in the loop - we can share GetName(i) via a
variable.

        for (var i = 0; i < dataRecord.FieldCount; i++)
        {
            string name = dataRecord.GetName(i);
            if(overriddenProperties.Contains(name))
                continue;

Finally the calls to CreateBuilder() need to have the extra parameter
supplied - context.GetContextTypeMap().GetPropertyMaps()

Reply to this email directly or view it on GitHubhttps://github.com/AutoMapper/AutoMapper/issues/273#issuecomment-35079680
.

[jbogard]

From @rlaveycal on April 24, 2014 13:40

Hi,

This didn't make 3.2...maybe 3.3?

Thanks

[jumas45]

Temporary Workaround: In my SQL whenever there is a datatype of int, long, decimal,float, double, I am casting it as a string and then I am creating an explicit .ForMember mapping for those columns. It's painful but works.