CODEWITHSUNDEEP
.netentity-frameworkormef-fluent-api
葛厚德
葛厚德

Reputation: 155

Does the EF Fluent Api can setting the Minimum Length?

It seems use the Fluent API has more flexibility.

So I choose the way to follow always use the Fluent API to determine the feature it have in db instead use the annotations to.

But here is the problem,I couldn't find the way to set the Minimum length. Is there a method to perform this?

And i notice,there are no much topic discuss this way.Is the Fluent API way popular??

Hope we choose the right side.

Upvotes: 9

Views: 8705

Answers (3)

RashmiMs
RashmiMs

Reputation: 189

Maybe late reply for this question still there is no way to specify using Fluent API.

But We can do from Check constraint using Fluent API to make sure Data length is greater than some length.

builder.HasCheckConstraint("CHK_DocumentLogo_ExtensionHasAtleastOneChar", "(DATALENGTH([Extension]) > 0)");

you need to install the Microsoft.EntityFrameworkCore.Relational NuGet package to use this extension method.

More info on HasCheckConstraint - https://learn.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.relationalentitytypebuilderextensions.hascheckconstraint?view=efcore-5.0

Upvotes: 0

Cyrus
Cyrus

Reputation: 2429

For string property use StringLength

[StringLength(30, MinimumLength = 5)]
public string MyStringProperty { get; set; }

https://msdn.microsoft.com/en-us/library/system.componentmodel.dataannotations.stringlengthattribute%28v=vs.110%29.aspx

Upvotes: 2

Alexander Derck
Alexander Derck

Reputation: 14498

This is impossible at the moment with EF. If you really have to set a minimum length, you can do it with an attribute though:

[MaxLength(10),MinLength(3)]
public string MyProperty {get; set;}

As the first comment under your question already says, it's probably not very common to have minimum length check in databases (never seen it myself), so this will just throw a validation error when you try to enter a value with a length smaller than 3.

Upvotes: 7

Related Questions