Implement EF.Functions.JsonExists translation for SQL Server (#31136)

src/EFCore.Relational/Extensions/RelationalDbFunctionsExtensions.cs

@@ -56,4 +56,17 @@ public static T Greatest<T>(
         this DbFunctions _,
         [NotParameterized] params T[] values)
         => throw new InvalidOperationException(CoreStrings.FunctionOnClient(nameof(Greatest)));
+
+    /// <summary>
+    ///     Returns a value indicating whether a given JSON path exists within the specified JSON.
+    ///     Usually corresponds to the <c>JSON_PATH_EXISTS</c> SQL function.
+    /// </summary>
+    /// <param name="_">The <see cref="DbFunctions" /> instance.</param>
+    /// <param name="json">The JSON value to check.</param>
+    /// <param name="path">The JSON path to look for.</param>
+    public static bool JsonExists(
+        this DbFunctions _,
+        object json,
+        string path)
+        => throw new InvalidOperationException(CoreStrings.FunctionOnClient(nameof(JsonExists)));
 }

src/EFCore.SqlServer/Query/Internal/SqlServerMethodCallTranslatorProvider.cs

@@ -38,6 +38,7 @@ public SqlServerMethodCallTranslatorProvider(
             new SqlServerFullTextSearchFunctionsTranslator(sqlExpressionFactory),
             new SqlServerIsDateFunctionTranslator(sqlExpressionFactory),
             new SqlServerIsNumericFunctionTranslator(sqlExpressionFactory),
+            new SqlServerJsonFunctionTranslator(sqlExpressionFactory),
             new SqlServerMathTranslator(sqlExpressionFactory),
             new SqlServerNewGuidTranslator(sqlExpressionFactory),
             new SqlServerObjectToStringTranslator(sqlExpressionFactory, typeMappingSource),

src/EFCore.SqlServer/Query/Internal/Translators/SqlServerJsonFunctionTranslator.cs

@@ -0,0 +1,39 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using Microsoft.EntityFrameworkCore.Query.SqlExpressions;
+
+// ReSharper disable once CheckNamespace
+namespace Microsoft.EntityFrameworkCore.SqlServer.Query.Internal;
+
+/// <summary>
+///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+///     any release. You should only use it directly in your code with extreme caution and knowing that
+///     doing so can result in application failures when updating to a new Entity Framework Core release.
+/// </summary>
+public class SqlServerJsonFunctionTranslator(ISqlExpressionFactory sqlExpressionFactory) : IMethodCallTranslator
+{
+    /// <summary>
+    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+    ///     any release. You should only use it directly in your code with extreme caution and knowing that
+    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
+    /// </summary>
+    public virtual SqlExpression? Translate(
+        SqlExpression? instance,
+        MethodInfo method,
+        IReadOnlyList<SqlExpression> arguments,
+        IDiagnosticsLogger<DbLoggerCategory.Query> logger)
+        => method.Name == nameof(RelationalDbFunctionsExtensions.JsonExists)
+            && method.DeclaringType == typeof(RelationalDbFunctionsExtensions)
+                ? sqlExpressionFactory.Equal(
+                    sqlExpressionFactory.Function(
+                        "JSON_PATH_EXISTS",
+                        [arguments[1], arguments[2]],
+                        nullable: true,
+                        argumentsPropagateNullability: [true, false],
+                        typeof(int)),
+                    sqlExpressionFactory.Constant(1))
+                : null;
+}

test/EFCore.SqlServer.FunctionalTests/Query/NorthwindDbFunctionsQuerySqlServerTest.cs

@@ -1348,6 +1348,25 @@ WHERE CAST(DATALENGTH(N'foo') AS int) = 3
         }
     }
 
+    [ConditionalFact, SqlServerCondition(SqlServerCondition.SupportsFunctions2022)]
+    public virtual async Task JsonExists_with_column()
+    {
+        await using var context = CreateContext();
+
+        // Note: Address is not valid JSON, so this will return no results,
+        // but the purpose is to verify the SQL translation is correct
+        var result = await context.Customers
+            .Where(c => EF.Functions.JsonExists(c.Address!, "$.city"))
+            .ToListAsync();
+
+        AssertSql(
+            """
+SELECT [c].[CustomerID], [c].[Address], [c].[City], [c].[CompanyName], [c].[ContactName], [c].[ContactTitle], [c].[Country], [c].[Fax], [c].[Phone], [c].[PostalCode], [c].[Region]
+FROM [Customers] AS [c]
+WHERE JSON_PATH_EXISTS([c].[Address], N'$.city') = 1
+""");
+    }
+
     private void AssertSql(params string[] expected)
         => Fixture.TestSqlLoggerFactory.AssertBaseline(expected);
 }