使用单个数据库但具有多个架构的多个dbContext从WebApi检索数据

Question

我在单个数据库中具有不同的模式，即主数据，订单，采购等。我们希望获取那些客户类型为预付款或后付款的客户的订单明细。我还在Web Api项目中创建了不同的区域，并具有多个dbContext。

以下代码已尝试：

private OrderContext db = new OrderContext();

// GET: api/Orders
public IQueryable<BookingHeader> GetBookingHeader()
{
    MasterContext masterContext = new MasterContext();

    return db.Orders.Where(par => MasterContext.Customers.Where(pa => pa.Customer_Type == "Prepaid").Any(pa => pa.Party_Code.Equals(par.Customer_Code)));
}

{
    "Message": "An error has occurred.",
    "ExceptionMessage": "The 'ObjectContent`1' type failed to serialize the response body for content type 'application/json; charset=utf-8'.",
    "ExceptionType": "System.InvalidOperationException",
    "StackTrace": null,
    "InnerException": {
        "Message": "An error has occurred.",
        "ExceptionMessage": "Cannot use multiple DbContext instances within a single query execution. Ensure the query uses a single context instance.",
        "ExceptionType": "System.InvalidOperationException",
        "StackTrace": "   at Microsoft.EntityFrameworkCore.Query.ExpressionVisitors.Internal.ParameterExtractingExpressionVisitor.ValidateQueryProvider(IQueryable queryable)\r\n   at Microsoft.EntityFrameworkCore.Query.ExpressionVisitors.Internal.ParameterExtractingExpressionVisitor.EvaluateQueryable(Expression expression)\r\n   at Microsoft.EntityFrameworkCore.Query.ExpressionVisitors.Internal.ParameterExtractingExpressionVisitor.VisitMember(MemberExpression memberExpression)\r\n   at System.Linq.Expressions.MemberExpression.Accept(ExpressionVisitor visitor)\r\n   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)\r\n   at System.Linq.Expressions.ExpressionVisitor.VisitArguments(IArgumentProvider nodes)\r\n   at System.Linq.Expressions.ExpressionVisitor.VisitMethodCall(MethodCallExpression node)\r\n   at Microsoft.EntityFrameworkCore.Query.ExpressionVisitors.Internal.ParameterExtractingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)\r\n   at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)\r\n   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)\r\n   at System.Linq.Expressions.ExpressionVisitor.VisitArguments(IArgumentProvider nodes)\r\n   at System.Linq.Expressions.ExpressionVisitor.VisitMethodCall(MethodCallExpression node)\r\n   at Microsoft.EntityFrameworkCore.Query.ExpressionVisitors.Internal.ParameterExtractingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)\r\n   at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)\r\n   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)\r\n   at Microsoft.EntityFrameworkCore.Query.ExpressionVisitors.Internal.ParameterExtractingExpressionVisitor.VisitBinary(BinaryExpression binaryExpression)\r\n   at System.Linq.Expressions.BinaryExpression.Accept(ExpressionVisitor visitor)\r\n   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)\r\n   at System.Linq.Expressions.ExpressionVisitor.VisitLambda[T](Expression`1 node)\r\n   at Microsoft.EntityFrameworkCore.Query.ExpressionVisitors.Internal.ParameterExtractingExpressionVisitor.VisitLambda[T](Expression`1 node)\r\n   at System.Linq.Expressions.Expression`1.Accept(ExpressionVisitor visitor)\r\n   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)\r\n   at System.Linq.Expressions.ExpressionVisitor.VisitUnary(UnaryExpression node)\r\n   at Microsoft.EntityFrameworkCore.Query.ExpressionVisitors.Internal.ParameterExtractingExpressionVisitor.VisitUnary(UnaryExpression unaryExpression)\r\n   at System.Linq.Expressions.UnaryExpression.Accept(ExpressionVisitor visitor)\r\n   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)\r\n   at System.Linq.Expressions.ExpressionVisitor.VisitArguments(IArgumentProvider nodes)\r\n   at System.Linq.Expressions.ExpressionVisitor.VisitMethodCall(MethodCallExpression node)\r\n   at Microsoft.EntityFrameworkCore.Query.ExpressionVisitors.Internal.ParameterExtractingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)\r\n   at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)\r\n   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)\r\n   at Microsoft.EntityFrameworkCore.Query.ExpressionVisitors.Internal.ParameterExtractingExpressionVisitor.ExtractParameters(Expression expression)\r\n   at Microsoft.EntityFrameworkCore.Query.Internal.QueryModelGenerator.ExtractParameters(IDiagnosticsLogger`1 logger, Expression query, IParameterValues parameterValues, Boolean parameterize, Boolean generateContextAccessors)\r\n   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.Execute[TResult](Expression query)\r\n   at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryProvider.Execute[TResult](Expression expression)\r\n   at Remotion.Linq.QueryableBase`1.System.Collections.IEnumerable.GetEnumerator()\r\n   at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeList(JsonWriter writer, IEnumerable values, JsonArrayContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)\r\n   at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerProperty)\r\n   at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.Serialize(JsonWriter jsonWriter, Object value, Type objectType)\r\n   at Newtonsoft.Json.JsonSerializer.SerializeInternal(JsonWriter jsonWriter, Object value, Type objectType)\r\n   at System.Net.Http.Formatting.BaseJsonMediaTypeFormatter.WriteToStream(Type type, Object value, Stream writeStream, Encoding effectiveEncoding)\r\n   at System.Net.Http.Formatting.JsonMediaTypeFormatter.WriteToStream(Type type, Object value, Stream writeStream, Encoding effectiveEncoding)\r\n   at System.Net.Http.Formatting.BaseJsonMediaTypeFormatter.WriteToStream(Type type, Object value, Stream writeStream, HttpContent content)\r\n   at System.Net.Http.Formatting.BaseJsonMediaTypeFormatter.WriteToStreamAsync(Type type, Object value, Stream writeStream, HttpContent content, TransportContext transportContext, CancellationToken cancellationToken)\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at System.Net.Http.HttpContent.<CopyToAsyncCore>d__44.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at System.Web.Http.WebHost.HttpControllerHandler.<WriteBufferedResponseContentAsync>d__22.MoveNext()"
    }
}