Fix NullReferenceException in MySqlJsonParameterExpressionVisitor

Copilot · renemadsen · Copilot · commit 65aa9e24b1a5 · 2025-12-17T18:16:39.000Z
Add null check for typeMapping before accessing ClrType property to prevent NullReferenceException when FindMapping returns null.

Co-authored-by: renemadsen &lt;76994+renemadsen@users.noreply.github.com&gt;
diff --git a/src/EFCore.MySql/Query/ExpressionVisitors/Internal/MySqlJsonParameterExpressionVisitor.cs b/src/EFCore.MySql/Query/ExpressionVisitors/Internal/MySqlJsonParameterExpressionVisitor.cs
@@ -37,7 +37,7 @@ protected virtual SqlExpression VisitParameter(SqlParameterExpression sqlParamet
 
                 // MySQL has a real JSON datatype, and string parameters need to be converted to it.
                 // MariaDB defines the JSON datatype just as a synonym for LONGTEXT.
-                if (!_options.ServerVersion.Supports.JsonDataTypeEmulation)
+                if (typeMapping is not null && !_options.ServerVersion.Supports.JsonDataTypeEmulation)
                 {
                     return _sqlExpressionFactory.Convert(
                         sqlParameterExpression,

Original file line number	Diff line number	Diff line change
`@@ -37,7 +37,7 @@ protected virtual SqlExpression VisitParameter(SqlParameterExpression sqlParamet`
`37`	`37`
`38`	`38`	`// MySQL has a real JSON datatype, and string parameters need to be converted to it.`
`39`	`39`	`// MariaDB defines the JSON datatype just as a synonym for LONGTEXT.`
`40`		`- if (!_options.ServerVersion.Supports.JsonDataTypeEmulation)`
	`40`	`+ if (typeMapping is not null && !_options.ServerVersion.Supports.JsonDataTypeEmulation)`
`41`	`41`	`{`
`42`	`42`	`return _sqlExpressionFactory.Convert(`
`43`	`43`	`sqlParameterExpression,`