I have a table with the following:
CREATE TABLE [Location]([ADDRESS1] [nvarchar](50) NOT NULL DEFAULT (' '));
I import it into Entity Framework 4.1.
Entity Frameworkâs designer shows this:
[EdmScalarPropertyAttribute(EntityKeyProperty=false, IsNullable=false)]
[DataMemberAttribute()]
public global::System.String ADDRESS1
{
get
{
return _ADDRESS1;
}
set
{
OnADDRESS1Changing(value);
ReportPropertyChanging("ADDRESS1");
_ADDRESS1 = StructuralObject.SetValidValue(value, false);
ReportPropertyChanged("ADDRESS1");
OnADDRESS1Changed();
}
}
private global::System.String _ADDRESS1 = " ";
partial void OnADDRESS1Changing(global::System.String value);
partial void OnADDRESS1Changed();
When I build it, I get a *.web.g.cs file in my Silverlight application and the field looks like this:
[DataMember()]
[Required()]
[StringLength(50)]
public string ADDRESS1
{
get
{
return this._address1;
}
set
{
if ((this._address1 != value))
{
this.OnADDRESS1Changing(value);
this.RaiseDataMemberChanging("ADDRESS1");
this.ValidateProperty("ADDRESS1", value);
this._address1 = value;
this.RaiseDataMemberChanged("ADDRESS1");
this.OnADDRESS1Changed();
}
}
}
Am I missing a setting in Entity Framework? It appears to me that if the field is NOT NULL code generation is flagging the field as required, even though I am telling it the default is string.empty (or blank).
NOT NULL means required. That's the only thing that controls where a value must be supplied.
An empty string for new records does not mean you can't explicitly insert a NULL value, but NOT NULL will stop you doing that.
Related
I have an ASP.NET Core MVC application that might be restarted from time to time (maintenance); how can make some variable values persistent from an execution to the next?
PS: That's the code that needs to write value as persistent. For example "LastMaintenanceRestartTime = 03/04-2020", the maintenance restart occurs once a day so the code needs to remember the last time it was restarted.
In UWP, I could do the following code but I can't seem to find an equivalent for ASP.NET Core:
Windows.Storage.ApplicationData.Current.LocalSettings.Values[key] = value;
The best I could find is the following code but the values are only persistent within the same execution:
AppDomain.CurrentDomain.SetData(key, value);
Some talk about "Application.Settings" but I can't seem to be able to reach this namespace...
I've also seen some people talking about "AppSettings" files that can be modified during execution but it seems rather complex to keep a simple value persistent...
Do you have any recommendation, solution or ideas for me?
I found the solution:
static void ReadSetting(string key)
{
try
{
var appSettings = ConfigurationManager.AppSettings;
string result = appSettings[key] ?? "Not Found";
Console.WriteLine(result);
}
catch (ConfigurationErrorsException)
{
Console.WriteLine("Error reading app settings");
}
}
static void AddUpdateAppSettings(string key, string value)
{
try
{
var configFile = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
var settings = configFile.AppSettings.Settings;
if (settings[key] == null)
{
settings.Add(key, value);
}
else
{
settings[key].Value = value;
}
configFile.Save(ConfigurationSaveMode.Modified);
ConfigurationManager.RefreshSection(configFile.AppSettings.SectionInformation.Name);
}
catch (ConfigurationErrorsException)
{
Console.WriteLine("Error writing app settings");
}
}
Link: https://learn.microsoft.com/en-us/dotnet/api/system.configuration.configurationmanager.appsettings?redirectedfrom=MSDN&view=dotnet-plat-ext-5.0#System_Configuration_ConfigurationManager_AppSettings
Create a model to save data and last execution time
public class ApplicationData {
public DateTime LastExecutionTime {get;set;}
public string Data {get;set;}
public bool isRunningFirstTime {get;set}
}
1.On first application run, model should be updated to current values and isRunningFirstTime should be set to false.
2. On second run, read or update values based on date and application running count
Expanding on #rashidali answer (and not saying best, but):
public class ApplicationData
{
private DateTime _lastExecutionTime;
public DateTime LastExecutionTime
{
get
{
_lastExecutionTime = (read from file/database);
return _lastExecutionTime;
}
set
{
_lastExecutionTime = value;
(write _lastExecutionTime to file/database);
}
}
public string Data {get;set;}
public bool isRunningFirstTime {get;set}
}
By default all the data member values in a parameter object to wcf service will be null. But how to check if actual null value was passed from the client to my service.
In otherwords if the client actually passed any values including null values to datamembers then I have to do some DB operations. So I need to distinguish between default null values and actual null values passed by client. Please advice.
I'm not sure this is what you asked but you can implement something like this in order to null check.
private bool HasNull(object webServiceInput, string[] optionalParameters = null)
{
if (ReferenceEquals(null, webServiceInput))
return false;
if (optionalParameters == null)
optionalParameters = new string[0];
var binding = BindingFlags.Instance | BindingFlags.Public;
var properties = webServiceInput.GetType().GetProperties(binding);
foreach (var property in properties)
{
if (!property.CanRead)
continue;
if (property.PropertyType.IsValueType)
continue;
if (optionalParameters.Contains(property.Name))
continue;
var value = property.GetValue(webServiceInput);
if (ReferenceEquals(null, value))
return false;
}
return true;
}
I think the only solution is to have extra data members following this pattern:
class Contract
{
[DataMember]
private string _field;
public string Field
{
get {
return _field;
}
set {
_field = value;
FieldSpecified = true;
}
}
[DataMember]
public string FieldSpecified;
}
This is the pattern that XML serialization uses.
I have a scenario where i need to use the payload as
{"authType":"PDS"}
or
{"authType":"xyz","authType2":"abc",}
or
{"authType":"xyz","authType2":"abc","authType3":"123"}
or
any combination except for null values.
referring to the code i have 3 fields but only not null value fields be used.
Basically i don't want to include the field which has null value.
Are there any annotations to be used to get it done
public class AuthJSONRequest {
private String authType;
private String authType2;
private String authType3;
public String getAuthType() {
return authType;
}
public void setAuthType(String authType) {
this.authType = authType;
}
public String getAuthType2() {
return authType2;
}
public void setAuthType2(String authType2) {
this.authType2 = authType2;
}
public String getAuthType3() {
return authType3;
}
public void setAuthType3(String authType3) {
this.authType3 = authType3;
}
}
Try JSON Views? See this or this. Or for more filtering features, see this blog entry (Json Filters for example).
This is exactly what the annotation #JsonInclude in Jackson2 and #JsonSerialize in Jackson are meant for.
If you want a property to show up only when it is not equal to null, add #JsonInclude(Include.NON_NULL) resp. #JsonSerialize(include=Include.NON_NULL).
By default, WCF deserializes missing elements into default values like null, 0 or false. The problem with this approach is that if it's a basic type like number 0 I'm not sure whether it means the real value sent by an external system or a default value generated by WCF.
So my question is: Is it possible to find out at run-time whether the default value means "I didn't send anything".
This is crucial because we can't update and overwrite existing data in the database with the default values just because the external system didn't send a particular element this time (data corruption).
Microsoft's short answer is "It is up to the receiving endpoint to appropriately interpret a missing element."
Data member default values
http://msdn.microsoft.com/en-us/library/aa347792.aspx
Can somebody please clarify what's that supposed to mean?
Thanks
If you define your data members as properties, you can use whether the setter was called or not to decide whether some value was sent. The code below shows one data contract which knows whether it deserialized its fields.
public class Post_51ca1ead_2f0a_4912_a451_374daab0101b
{
[DataContract(Name = "Person", Namespace = "")]
public class Person
{
string name;
int age;
bool nameWasSent;
bool ageWasSent;
[DataMember]
public string Name
{
get
{
return this.name;
}
set
{
this.nameWasSent = true;
this.name = value;
}
}
[DataMember]
public int Age
{
get
{
return this.age;
}
set
{
this.ageWasSent = true;
this.age = value;
}
}
[OnDeserializing]
void OnDeserializing(StreamingContext ctx)
{
this.ageWasSent = false;
this.nameWasSent = false;
}
public override string ToString()
{
return string.Format("Person[Name={0},Age={1}]",
nameWasSent ? name : "UNSPECIFIED",
ageWasSent ? age.ToString() : "UNSPECIFIED");
}
}
public static void Test()
{
MemoryStream ms = new MemoryStream();
DataContractSerializer dcs = new DataContractSerializer(typeof(Person));
dcs.WriteObject(ms, new Person { Name = "John", Age = 30 });
Console.WriteLine(Encoding.UTF8.GetString(ms.ToArray()));
string noAge = "<Person><Name>John</Name></Person>";
ms = new MemoryStream(Encoding.UTF8.GetBytes(noAge));
object p = dcs.ReadObject(ms);
Console.WriteLine("No age: {0}", p);
string noName = "<Person><Age>45</Age></Person>";
ms = new MemoryStream(Encoding.UTF8.GetBytes(noName));
p = dcs.ReadObject(ms);
Console.WriteLine("No name: {0}", p);
}
}
We are using fluentnhibernate with automapping and we have a naming convention that all columns that are foreign keys, there column name will end with "Key". So we have a convention that looks like this:
public class ForeignKeyColumnNameConvention : IReferenceConvention
{
public void Apply ( IManyToOneInstance instance )
{
// name the key field
string propertyName = instance.Property.Name;
instance.Column ( propertyName + "Key" );
}
}
This works great until we created a component in which one of its values is a foreign key. By renaming the column here it overrides the default name given to the component column which includes the ComponentPrefix which is defined in the AutomappingConfiguration. Is there a way for me to get the ComponentPrefix in this convention? or is there some other way for me to get the column name for components with a property that is a foreign key to end in the word "Key"?
After a lot of fiddling and trial & error (thus being tempted to use your solution with Reflection) I came up with the following:
This method depends on the order of the execution of the conventions. This convention-order happens via a strict hierarchy. In this example, at first, the convention of the component (IDynamicComponentConvention) is being handled and after that the conventions of the inner properties are being handled such as the References mapping (IReferenceConvention).
The strict order is where we make our strike:
We assemble the correct name of the column in the call to Apply(IDynamicComponentConvention instance), put it on the queue. Note that a Queue<T> is used which is a FIFO (first-in-first-out) collection type thus it keeps the order correctly.
Almost immediately after that, Apply(IManyToOneInstanceinstance) is called. We check if there is anything in the queue. If there is, we take it out of the queue and set it as column name. Note that you should not use Peek() instead of Dequeue() as it does not remove the object from the queue.
The code is as follows:
public sealed class CustomNamingConvention : IDynamicComponentConvention, IReferenceConvention {
private static Queue<string> ColumnNames = new Queue<string>();
public void Apply(IDynamicComponentInstance instance) {
foreach (var referenceInspector in instance.References) {
// All the information we need is right here
// But only to inspect, no editing yet :(
// Don't worry, just assemble the name and enqueue it
var name = string.Format("{0}_{1}",
instance.Name,
referenceInspector.Columns.Single().Name);
ColumnNames.Enqueue(name);
}
}
public void Apply(IManyToOneInstance instance) {
if (!ColumnNames.Any())
// Nothing in the queue? Just return then (^_^)
return;
// Set the retrieved string as the column name
var columnName = ColumnNames.Dequeue();
instance.Column(columnName);
// Pick a beer and celebrate the correct naming!
}
}
I Have figured out a way to do this using reflection to get to the underlying mapping of the IManyToOneInspector exposed by the IComponentInstance but was hoping there was a better way to do this?
Here is some example code of how I achieved this:
#region IConvention<IComponentInspector, IComponentInstance> Members
public void Apply(IComponentInstance instance)
{
foreach (var manyToOneInspector in instance.References)
{
var referenceName = string.Format("{0}_{1}_{2}{3}", instance.EntityType.Name, manyToOneInspector.Property.PropertyType.Name, _autoMappingConfiguration.GetComponentColumnPrefix(instance.Property), manyToOneInspector.Property.Name);
if(manyToOneInspector.Property.PropertyType.IsSubclassOf(typeof(LookupBase)))
{
referenceName += "Lkp";
}
manyToOneInspector.Index ( string.Format ( "{0}_FK_IDX", referenceName ) );
}
}
#endregion
public static class ManyToOneInspectorExtensions
{
public static ManyToOneMapping GetMapping(this IManyToOneInspector manyToOneInspector)
{
var fieldInfo = manyToOneInspector.GetType ().GetField( "mapping", BindingFlags.NonPublic | BindingFlags.Instance );
if (fieldInfo != null)
{
var manyToOneMapping = fieldInfo.GetValue( manyToOneInspector ) as ManyToOneMapping;
return manyToOneMapping;
}
return null;
}
public static void Index(this IManyToOneInspector manyToOneInspector, string indexName)
{
var mapping = manyToOneInspector.GetMapping ();
mapping.Index ( indexName );
}
public static void Column(this IManyToOneInspector manyToOneInspector, string columnName)
{
var mapping = manyToOneInspector.GetMapping ();
mapping.Column ( columnName );
}
public static void ForeignKey(this IManyToOneInspector manyToOneInspector, string foreignKeyName)
{
var mapping = manyToOneInspector.GetMapping();
mapping.ForeignKey ( foreignKeyName );
}
}
public static class ManyToOneMappingExtensions
{
public static void Index (this ManyToOneMapping manyToOneMapping, string indexName)
{
if (manyToOneMapping.Columns.First().IsSpecified("Index"))
return;
foreach (var column in manyToOneMapping.Columns)
{
column.Index = indexName;
}
}
public static void Column(this ManyToOneMapping manyToOneMapping, string columnName)
{
if (manyToOneMapping.Columns.UserDefined.Count() > 0)
return;
var originalColumn = manyToOneMapping.Columns.FirstOrDefault();
var column = originalColumn == null ? new ColumnMapping() : originalColumn.Clone();
column.Name = columnName;
manyToOneMapping.ClearColumns();
manyToOneMapping.AddColumn(column);
}
public static void ForeignKey(this ManyToOneMapping manyToOneMapping, string foreignKeyName)
{
if (!manyToOneMapping.IsSpecified("ForeignKey"))
manyToOneMapping.ForeignKey = foreignKeyName;
}
}