C# DbProviderFactory.GetProviderServices方法代码示例

        internal EntityCommandDefinition(
            DbProviderFactory storeProviderFactory,
            DbCommandTree commandTree, 
            DbInterceptionContext interceptionContext,
            IDbDependencyResolver resolver = null,
            BridgeDataReaderFactory bridgeDataReaderFactory = null,
            ColumnMapFactory columnMapFactory = null)
        {
            DebugCheck.NotNull(storeProviderFactory);
            DebugCheck.NotNull(commandTree);
            DebugCheck.NotNull(interceptionContext);

            _bridgeDataReaderFactory = bridgeDataReaderFactory ?? new BridgeDataReaderFactory();
            _columnMapFactory = columnMapFactory ?? new ColumnMapFactory();

            _storeProviderServices =
                (resolver != null
                     ? resolver.GetService<DbProviderServices>(storeProviderFactory.GetProviderInvariantName())
                     : null) ??
                storeProviderFactory.GetProviderServices();

            try
            {
                if (DbCommandTreeKind.Query
                    == commandTree.CommandTreeKind)
                {
                    // Next compile the plan for the command tree
                    var mappedCommandList = new List<ProviderCommandInfo>();
                    ColumnMap columnMap;
                    int columnCount;
                    PlanCompiler.Compile(commandTree, out mappedCommandList, out columnMap, out columnCount, out _entitySets);
                    _columnMapGenerators = new IColumnMapGenerator[] { new ConstantColumnMapGenerator(columnMap, columnCount) };
                    // Note: we presume that the first item in the ProviderCommandInfo is the root node;
                    Debug.Assert(mappedCommandList.Count > 0, "empty providerCommandInfo collection and no exception?");
                    // this shouldn't ever happen.

                    // Then, generate the store commands from the resulting command tree(s)
                    _mappedCommandDefinitions = new List<DbCommandDefinition>(mappedCommandList.Count);

                    foreach (var providerCommandInfo in mappedCommandList)
                    {
                        var providerCommandDefinition = _storeProviderServices.CreateCommandDefinition(
                            providerCommandInfo.CommandTree, interceptionContext);

                        if (null == providerCommandDefinition)
                        {
                            throw new ProviderIncompatibleException(Strings.ProviderReturnedNullForCreateCommandDefinition);
                        }

                        _mappedCommandDefinitions.Add(providerCommandDefinition);
                    }
                }
                else
                {
                    Debug.Assert(
                        DbCommandTreeKind.Function == commandTree.CommandTreeKind, "only query and function command trees are supported");
                    var entityCommandTree = (DbFunctionCommandTree)commandTree;

                    // Retrieve mapping and metadata information for the function import.
                    var mapping = GetTargetFunctionMapping(entityCommandTree);
                    IList<FunctionParameter> returnParameters = entityCommandTree.EdmFunction.ReturnParameters;
                    var resultSetCount = returnParameters.Count > 1 ? returnParameters.Count : 1;
                    _columnMapGenerators = new IColumnMapGenerator[resultSetCount];
                    var storeResultType = DetermineStoreResultType(mapping, 0, out _columnMapGenerators[0]);
                    for (var i = 1; i < resultSetCount; i++)
                    {
                        DetermineStoreResultType(mapping, i, out _columnMapGenerators[i]);
                    }

                    // Copy over parameters (this happens through a more indirect route in the plan compiler, but
                    // it happens nonetheless)
                    var providerParameters = new List<KeyValuePair<string, TypeUsage>>();
                    foreach (var parameter in entityCommandTree.Parameters)
                    {
                        providerParameters.Add(parameter);
                    }

                    // Construct store command tree usage.
                    var providerCommandTree = new DbFunctionCommandTree(
                        entityCommandTree.MetadataWorkspace, DataSpace.SSpace,
                        mapping.TargetFunction, storeResultType, providerParameters);

                    var storeCommandDefinition = _storeProviderServices.CreateCommandDefinition(providerCommandTree);
                    _mappedCommandDefinitions = new List<DbCommandDefinition>(1)
                        {
                            storeCommandDefinition
                        };

                    var firstResultEntitySet = mapping.FunctionImport.EntitySets.FirstOrDefault();
                    if (firstResultEntitySet != null)
                    {
                        _entitySets = new Set<EntitySet>();
                        _entitySets.Add(mapping.FunctionImport.EntitySets.FirstOrDefault());
                        _entitySets.MakeReadOnly();
                    }
                }

                // Finally, build a list of the parameters that the resulting command should have;
                var parameterList = new List<EntityParameter>();

//.........这里部分代码省略.........