Add Translation for to_date and to_timestamp as DBFunctions extensions

src/EFCore.PG/Extensions/DbFunctionsExtensions/NpgsqlDbFunctionsExtensions.cs

@@ -141,4 +141,24 @@ public static int Distance(this DbFunctions _, DateOnly a, DateOnly b)
     /// </remarks>
     public static TimeSpan Distance(this DbFunctions _, DateTime a, DateTime b)
         => throw new InvalidOperationException(CoreStrings.FunctionOnClient(nameof(Distance)));
+
+    /// <summary>
+    ///     Converts string to date according to the given format.
+    /// </summary>
+    /// <param name="_">The <see cref="DbFunctions"/> instance.</param>
+    /// <param name="value">The string to be converted.</param>
+    /// <param name="format">The format of the input date.</param>
+    /// <see href="https://www.postgresql.org/docs/current/functions-formatting.html" />
+    public static DateOnly? ToDate(this DbFunctions _, string? value, string? format)
+        => throw new InvalidOperationException(CoreStrings.FunctionOnClient(nameof(ToDate)));
+
+    /// <summary>
+    ///     Converts string to time stamp according to the given format.
+    /// </summary>
+    /// <param name="_">The <see cref="DbFunctions"/> instance.</param>
+    /// <param name="value">The string to be converted</param>
+    /// <param name="format">The format of the input date</param>
+    /// <see href="https://www.postgresql.org/docs/current/functions-formatting.html" />
+    public static DateTime? ToTimestamp(this DbFunctions _, string? value, string? format)
+        => throw new InvalidOperationException(CoreStrings.FunctionOnClient(nameof(ToTimestamp)));
 }

src/EFCore.PG/Query/ExpressionTranslators/Internal/NpgsqlStringMethodTranslator.cs

@@ -78,6 +78,12 @@ public class NpgsqlStringMethodTranslator : IMethodCallTranslator
     private static readonly MethodInfo StringToArrayNullString = typeof(NpgsqlDbFunctionsExtensions).GetRuntimeMethod(
         nameof(NpgsqlDbFunctionsExtensions.StringToArray), [typeof(DbFunctions), typeof(string), typeof(string), typeof(string)])!;
 
+    private static readonly MethodInfo ToDate = typeof(NpgsqlDbFunctionsExtensions).GetRuntimeMethod(
+        nameof(NpgsqlDbFunctionsExtensions.ToDate), [typeof(DbFunctions), typeof(string), typeof(string)])!;
+
+    private static readonly MethodInfo ToTimestamp = typeof(NpgsqlDbFunctionsExtensions).GetRuntimeMethod(
+        nameof(NpgsqlDbFunctionsExtensions.ToTimestamp), [typeof(DbFunctions), typeof(string), typeof(string)])!;
+
     private static readonly MethodInfo FirstOrDefaultMethodInfoWithoutArgs
         = typeof(Enumerable).GetRuntimeMethods().Single(
             m => m.Name == nameof(Enumerable.FirstOrDefault)
@@ -425,6 +431,30 @@ public NpgsqlStringMethodTranslator(NpgsqlTypeMappingSource typeMappingSource, I
                 _typeMappingSource.FindMapping(typeof(string[])));
         }
 
+        if (method == ToDate)
+        {
+            return _sqlExpressionFactory.Function(
+                "to_date",
+                new[] { arguments[1], arguments[2] },
+                nullable: true,
+                argumentsPropagateNullability: new[] { true, true },
+                typeof(DateOnly?),
+                _typeMappingSource.FindMapping(typeof(DateOnly))
+            );
+        }
+
+        if (method == ToTimestamp)
+        {
+            return _sqlExpressionFactory.Function(
+                "to_timestamp",
+                new[] { arguments[1], arguments[2] },
+                nullable: true,
+                argumentsPropagateNullability: new[] { true, true },
+                typeof(DateTime?),
+                _typeMappingSource.FindMapping(typeof(DateTime))
+            );
+        }
+
         return null;
     }
 

test/EFCore.PG.FunctionalTests/Query/NorthwindDbFunctionsQueryNpgsqlTest.cs

@@ -227,6 +227,34 @@ WHERE string_to_array(c."ContactName", ' ', 'Maria') = ARRAY[NULL,'Anders']::tex
 """);
     }
 
+    [Fact]
+    public void ToDate()
+    {
+        using var context = CreateContext();
+        var count = context.Orders.Count(c => EF.Functions.ToDate(c.OrderDate.ToString(), "YYYY-MM-DD") < new DateOnly(2000, 01, 01));
+        Assert.Equal(830, count);
+        AssertSql(
+"""
+SELECT count(*)::int
+FROM "Orders" AS o
+WHERE to_date(o."OrderDate"::text, 'YYYY-MM-DD') < DATE '2000-01-01'
+""");
+    }
+
+    [Fact]
+    public void ToTimestamp()
+    {
+        using var context = CreateContext();
+        var count = context.Orders.Count(c => EF.Functions.ToTimestamp(c.OrderDate.ToString(), "YYYY-MM-DD") < new DateTime(2000, 01, 01, 0,0,0, DateTimeKind.Utc));
+        Assert.Equal(830, count);
+        AssertSql(
+            """
+SELECT count(*)::int
+FROM "Orders" AS o
+WHERE to_timestamp(o."OrderDate"::text, 'YYYY-MM-DD') < TIMESTAMPTZ '2000-01-01T00:00:00Z'
+""");
+    }
+
     #endregion
 
     private void AssertSql(params string[] expected)