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+---
+layout: post
+title: "Entity Framework Core 8.0 Breaking Changes & SQL Compatibility Level"
+description: "If you are moving to .NET 8, be aware of this breaking change..."
+date: 2024-09-08 23:59
+author: Robert Muehsig
+tags: [Entity Framework Core, .NET Core 8]
+language: en
+---
+
+{% include JB/setup %}
+
+We recently switched from .NET 6 to .NET 8 and encountered the following Entity Framework Core error:
+
+```
+Microsoft.Data.SqlClient.SqlException: 'Incorrect syntax near the keyword 'WITH'....
+```
+
+The EF code uses the `Contains` method as shown below:
+
+```
+var names = new[] { "Blog1", "Blog2" };
+
+var blogs = await context.Blogs
+    .Where(b => names.Contains(b.Name))
+    .ToArrayAsync();
+```
+
+Before .NET 8 this would result in the following Sql statement:
+
+```
+SELECT [b].[Id], [b].[Name]
+FROM [Blogs] AS [b]
+WHERE [b].[Name] IN (N'Blog1', N'Blog2')
+```
+
+... and with .NET 8 it uses the `OPENJSON` function, which is __not supported on older versions like SQL Server 2014 or if the compatibility level is below 130 (!)__
+
+- See [this blogpost](https://devblogs.microsoft.com/dotnet/announcing-ef8-preview-4/) for more information about the `OPENJSON` change.
+
+# The fix is "simple"
+
+Ensure you're not using an unsupported SQL version __and__ that the `Compatibility Level` is at least on __level 130__.
+
+If you can't change the system, then you could also enforce the "old" behavior with a setting like this (not recommended, because it is slower!)
+
+```
+...
+.UseSqlServer(@"<CONNECTION STRING>", o => o.UseCompatibilityLevel(120));
+```
+
+# How to make sure your database is on Compatibility Level 130?
+
+Run this statement to check the compatibility level:
+
+```
+SELECT name, compatibility_level FROM sys.databases;
+``` 
+
+We updated our test/dev SQL Server and then moved all databases to the latest version with this SQL statement:
+
+```
+DECLARE @DBName NVARCHAR(255)
+DECLARE @SQL NVARCHAR(MAX)
+
+-- Cursor to loop through all databases
+DECLARE db_cursor CURSOR FOR
+SELECT name
+FROM sys.databases
+WHERE name NOT IN ('master', 'tempdb', 'model', 'msdb') -- Exclude system databases
+
+OPEN db_cursor
+FETCH NEXT FROM db_cursor INTO @DBName
+
+WHILE @@FETCH_STATUS = 0
+BEGIN
+    -- Construct the ALTER DATABASE command
+    SET @SQL = 'ALTER DATABASE [' + @DBName + '] SET COMPATIBILITY_LEVEL = 150;'
+    EXEC sp_executesql @SQL
+
+    FETCH NEXT FROM db_cursor INTO @DBName
+END
+
+CLOSE db_cursor
+DEALLOCATE db_cursor
+```
+
+# Check EF Core Breaking Changes
+
+There are other breaking changes, but only the first one affected us: [Breaking Changes](https://learn.microsoft.com/en-us/ef/core/what-is-new/ef-core-8.0/breaking-changes#sqlserver-contains-compatibility)
+
+Hope this helps!