feat: User-friendly error messages for db constraint violations (#470)

CHANGELOG.md

@@ -1,5 +1,8 @@
-# 5.0.4
+# 5.1.0
 
+- feat: Automatically produce user-friendly response messages in behaviors for Save and Delete operations that fail due to a violation of a SQL Server foreign key or unique constraint. This behavior can be controlled with the `DetailedEfConstraintExceptionMessages` setting in `.AddCoalesce(c => c.Configure(o => { ... }))`, or by overriding `StandardBehaviors.GetExceptionResult`. This is not a substitute for adding proper validation or other handling of related entities - it only exists to provide a better user experience in cases where the developer has forgotten to handle these situations. This behavior does respect Coalesce's security model and won't produce descriptions of types or values that the user is not allowed to see.
+
+- refactor: `CoalesceOptions.DetailedEntityFrameworkExceptionMessages` has been renamed to `CoalesceOptions.DetailedEFMigrationExceptionMessages`
 - fix: The "Max _N_ items retrieved" message in c-select now accounts for list calls that don't provide a count, e.g. by passing `noCount=true`.
 
 # 5.0.3

playground/Coalesce.Domain/AppDbContext.cs

@@ -52,6 +52,12 @@ protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
 
         protected override void OnModelCreating(ModelBuilder modelBuilder)
         {
+            // Remove cascading deletes.
+            foreach (var relationship in modelBuilder.Model.GetEntityTypes().SelectMany(e => e.GetForeignKeys()))
+            {
+                relationship.DeleteBehavior = DeleteBehavior.Restrict;
+            }
+
             modelBuilder.Entity<Product>().OwnsOne(p => p.Details, cb =>
             {
                 cb.OwnsOne(c => c.ManufacturingAddress);