From 1d9bfc6312d4082365f450d4bb5a076b3ceaebdd Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 10 Jun 2026 18:30:43 +0000
Subject: [PATCH 1/2] Initial plan


From 8231f2b5fcb1fc488c80e9eab6a5ab823dd3eed9 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 10 Jun 2026 18:39:13 +0000
Subject: [PATCH 2/2] Fix NRE for mistyped string default value on non-string
 column; add test

Co-authored-by: AndriySvyryd <6539701+AndriySvyryd@users.noreply.github.com>
---
 src/EFCore/Storage/TypeMappingSourceBase.cs   |  1 +
 .../SqlServerMigrationsSqlGeneratorTest.cs    | 20 +++++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/src/EFCore/Storage/TypeMappingSourceBase.cs b/src/EFCore/Storage/TypeMappingSourceBase.cs
index fe2f88ff815..c017b5592c9 100644
--- a/src/EFCore/Storage/TypeMappingSourceBase.cs
+++ b/src/EFCore/Storage/TypeMappingSourceBase.cs
@@ -149,6 +149,7 @@ protected virtual bool TryFindJsonCollectionMapping(
         out JsonValueReaderWriter? collectionReaderWriter)
     {
         if ((providerClrType == null || providerClrType == typeof(string))
+            && modelClrType != typeof(string)
             && modelClrType.TryGetElementType(typeof(IEnumerable<>)) is { } elementType
             && elementType != modelClrType
             && !modelClrType.GetGenericTypeImplementations(typeof(IDictionary<,>)).Any())
diff --git a/test/EFCore.SqlServer.FunctionalTests/Migrations/SqlServerMigrationsSqlGeneratorTest.cs b/test/EFCore.SqlServer.FunctionalTests/Migrations/SqlServerMigrationsSqlGeneratorTest.cs
index ebf25dd14e7..2567dda3368 100644
--- a/test/EFCore.SqlServer.FunctionalTests/Migrations/SqlServerMigrationsSqlGeneratorTest.cs
+++ b/test/EFCore.SqlServer.FunctionalTests/Migrations/SqlServerMigrationsSqlGeneratorTest.cs
@@ -79,6 +79,26 @@ public void CreateIndexOperation_unique_datacompression(DataCompressionType data
 """);
     }
 
+    [Fact]
+    public virtual void AddColumnOperation_mistyped_default_legacy()
+    {
+        Generate(
+            new AddColumnOperation
+            {
+                Table = "People",
+                Name = "Id",
+                ClrType = typeof(int),
+                ColumnType = "int",
+                DefaultValue = "",
+                IsNullable = false
+            });
+
+        AssertSql(
+            """
+ALTER TABLE [People] ADD [Id] int NOT NULL DEFAULT N'';
+""");
+    }
+
     [Fact]
     public virtual void AddColumnOperation_identity_legacy()
     {