I have a grails domain class that looks like:
class Person {
String name
int age
}
When I show the default "create" view (using scaffolding), the age field shows as a required field (with an asterisk next to it). Is there a way to make it show up as non-required and default to blank?
I've tried adding
constraints = {
age blank:true, nullable:true
}
This results in the field being allowed to be empty but it still shows up with the asterisk next to it.
An int is a primitive type and cannot be blank. You would have to change it to an Integer, then a null value would mean that it's blank.
Related
I have mentioned two fields(Name, Age) in my golang Struct after few days I have added one more fields in my database(Name,Age, Salary ) not in golandg struct.It shows errors like(Error 1364: Field 'salary' doesn't have a default value). How to ignore fileds in my struct dynamically
type Employee struct {
Name string `json:"name"
Age int `json:"age"
}
In future i will add more fileds but i don't want mention in struct
Based on the error you are getting, it seems like you are trying to insert a row into a MySQL database, and the new row you added does not have a default value. So your options are to :
Add a default value to the new column - See: https://dev.mysql.com/doc/refman/8.0/en/data-type-defaults.html
Add a field for the column into your Go struct and supply a value for it.
I have a base entity and 3 inherited sub-entities, called NoteItem, ImageItem and MapItem. The base entity class is marked with the [InheritanceMapping] attribute and has a Discriminator column. Everything works fine, except the third MapItem entity, which contains 4 columns of type double and bool.
For example, if I insert the a NoteItem entity it will throw an exception:
SqlCeException - Column Pitch can not contain NULL values
Pitch is column with double type. Only if I extend the [Column] attribute of each double and bool column with the CanBeNull = true addition, then it works.
It seems to me that there's a problem with double and bool values, because a column with type string must not explicitly contain the CanBeNull addition.
Is this a known problem or am I wrong?
there's a problem with double and bool values
AFAIK the behavior is by design.
a column with type string must not explicitly contain the CanBeNull addition
A string CLR value can be null, thus without [Column( CanBeNull = false )] attribute specified, the entity framework generates column that can be null. OTOH, bool and double values can't be null, if you want to allow nulls, you must specify [Column( CanBeNull = true )]
If you don't want to decorate your double and bool properties/fields with [Column] attributes, you could e.g. define them as double? and bool?, respectively.
I have an Invoice
class Invoice{
static hasMany = [lineItems: InvoiceItem]
double total
}
class InvoiceItem{
String description
double price
double qty
}
My issue is with form validation. If a user enters a string or invalid number format in either price or qty I get a
Failed to convert property value of type java.lang.String
to required type double for property price
BUT the error is in the Invoice object NOT in the LineItems object therefore I cannot highlight in RED the form appropriately. (And field value remains at zero when displayed so message is somewhat meaningless to user)
I was thinking of using COMMAND object with String parameters and validating their numeric value but I can't figure how to bind the InvoiceItem List.
What is the appropriate Grails way?
I could do all validation on the client side in javascript but that is not my question
You can do it with command objects. You need to read:
http://blog.peterdelahunty.com/2009/01/cool-way-to-dynamically-add-entries-to.html
command object data binding
Grails command object data binding
http://grails.1312388.n4.nabble.com/validating-nested-command-objects-td1346994.html
What is the difference in behavior of [MaxLength] and [StringLength] attributes?
As far as I can tell (with the exception that [MaxLength] can validate the maximum length of an array) these are identical and somewhat redundant?
MaxLength is used for the Entity Framework to decide how large to make a string value field when it creates the database.
From MSDN:
Specifies the maximum length of array
or string data allowed in a property.
StringLength is a data annotation that will be used for validation of user input.
From MSDN:
Specifies the minimum and maximum
length of characters that are allowed
in a data field.
Some quick but extremely useful additional information that I just learned from another post, but can't seem to find the documentation for (if anyone can share a link to it on MSDN that would be amazing):
The validation messages associated with these attributes will actually replace placeholders associated with the attributes. For example:
[MaxLength(100, "{0} can have a max of {1} characters")]
public string Address { get; set; }
Will output the following if it is over the character limit:
"Address can have a max of 100 characters"
The placeholders I am aware of are:
{0} = Property Name
{1} = Max Length
{2} = Min Length
Much thanks to bloudraak for initially pointing this out.
Following are the results when we use both [MaxLength] and [StringLength] attributes, in EF code first. If both are used, [MaxLength] wins the race. See the test result in studentname column in below class
public class Student
{
public Student () {}
[Key]
[Column(Order=1)]
public int StudentKey { get; set; }
//[MaxLength(50),StringLength(60)] //studentname column will be nvarchar(50)
//[StringLength(60)] //studentname column will be nvarchar(60)
[MaxLength(50)] //studentname column will be nvarchar(50)
public string StudentName { get; set; }
[Timestamp]
public byte[] RowVersion { get; set; }
}
All good answers...From the validation perspective, I also noticed that MaxLength gets validated at the server side only, while StringLength gets validated at client side too.
One another point to note down is in MaxLength attribute you can only provide max required range not a min required range.
While in StringLength you can provide both.
MaxLengthAttribute means Max. length of array or string data allowed
StringLengthAttribute means Min. and max. length of characters that are allowed in a data field
Visit http://joeylicc.wordpress.com/2013/06/20/asp-net-mvc-model-validation-using-data-annotations/
You can use :
[StringLength(8, ErrorMessage = "{0} length must be between {2} and {1}.", MinimumLength = 6)]
public string Address { get; set; }
The error message created by the preceding code would be "Address length must be between 6 and 8.".
MSDN: https://learn.microsoft.com/en-us/aspnet/core/mvc/models/validation?view=aspnetcore-5.0
I have resolved it by adding below line in my context:
modelBuilder.Entity<YourObject>().Property(e => e.YourColumn).HasMaxLength(4000);
Somehow, [MaxLength] didn't work for me.
When using the attribute to restrict the maximum input length for text from a form on a webpage, the StringLength seems to generate the maxlength html attribute (at least in my test with MVC 5). The one to choose then depnds on how you want to alert the user that this is the maximum text length. With the stringlength attribute, the user will simply not be able to type beyond the allowed length. The maxlength attribute doesn't add this html attribute, instead it generates data validation attributes, meaning the user can type beyond the indicated length and that preventing longer input depends on the validation in javascript when he moves to the next field or clicks submit (or if javascript is disabled, server side validation). In this case the user can be notified of the restriction by an error message.
Ok, I'll explain this as much as I can...
I've got a Site Lookup Column called EEE Content Type which refers to the Site Content Item Type Types List.
Now in my custom list (which inherits from Item), I am referencing that column, and it comes up in sharepoint fine and displays the lookup values.
The issue is when I'm using SPMetal.exe to generate the types it whinges about "Key isn't present in the dictionary" and fails. So I remove the definition of the column in the parameters.xml file for SPMetal, and re-generate the classes.
Now I've manually added the property and association.
private EntityRef<SiteContentItemTypeItem> _eeeContentType;
[Association(Name = "EEE_x0020_Content_x0020_Type", Storage = "_eeeContentType", MultivalueType = AssociationType.Single, List = "Site Content Item Types")]
public SiteContentItemTypeItem EEEContentType
{
get
{
return this._eeeContentType.GetEntity();
}
set
{
this._eeeContentType.SetEntity(value);
}
}
SiteContentItemTypeItem inherits from Item so its class is empty.
But when I load the custom list I have created, i get the first entry and the EEEContentType field is null...
using (IntranetDataContext context = new IntranetDataContext("http://siteurl")) {
context.ObjectTrackingEnabled = false;
EntityList<SiteContentItem> alerts = context.GetList<SiteContentItem>("User Alerts");
SiteContentItem alert = (from tmpalert in alerts where tmpalert.Id == 1 select tmpalert).First();
SiteContentItemTypeItem contentType = alert.EEEContentType;
}
I'm all out of ideas...
Should the List value in the Association attribute be that of a collection in the class or is it refering to the actual lookup list name?
Figured it out...
Stupid of me to "assume" when creating site lookup columns via code that SharePoint would use the proper naming conventions for FieldNames with spaces.
So the fieldName was correct, its InternalName wasn't the one I was expecting. And as sharepoint linq requires the internal names, it was throwing internal exceptions in the Linq.SharePoint DLL.