Fix string methods related to LastOrDefault and Contains (#175)

* Fix string methods related to LastOrDefault and Contains

src/EFCore.Jet/Query/ExpressionTranslators/Internal/JetStringMethodTranslator.cs

@@ -239,18 +239,29 @@ namespace EntityFrameworkCore.Jet.Query.ExpressionTranslators.Internal
             if (_lastOrDefaultMethodInfoWithoutArgs.Equals(method))
             {
                 var argument = arguments[0];
+                var lenfunction = _sqlExpressionFactory.Function(
+                    "LEN",
+                    new[] { argument },
+                    nullable: true,
+                    argumentsPropagateNullability: new[] { true },
+                    typeof(int));
+                var casefunc = _sqlExpressionFactory.Case(
+                    new[]
+                    {
+                        new CaseWhenClause(
+                            _sqlExpressionFactory.Equal(
+                                lenfunction,
+                                _sqlExpressionFactory.Constant(0)),
+                            _sqlExpressionFactory.Constant(1))
+                    },
+                    lenfunction);
                 return _sqlExpressionFactory.Function(
                     "MID",
                     new[]
                     {
                             argument,
                             _sqlExpressionFactory.Coalesce(
-                                _sqlExpressionFactory.Function(
+                                casefunc,
-                                    "LEN",
-                                    new[] { argument },
-                                    nullable: true,
-                                    argumentsPropagateNullability: new[] { true },
-                                    typeof(int)),
                                 _sqlExpressionFactory.Constant(0)
                             ),
                             _sqlExpressionFactory.Constant(1)

src/EFCore.Jet/Query/Internal/JetSqlTranslatingExpressionVisitor.cs

@@ -334,7 +334,7 @@ public class JetSqlTranslatingExpressionVisitor : RelationalSqlTranslatingExpres
                                         _sqlExpressionFactory.GreaterThan(
                                             _sqlExpressionFactory.Function(
                                                 "INSTR",
-                                                new[] { _sqlExpressionFactory.Constant(1), translatedPattern, translatedInstance, _sqlExpressionFactory.Constant(1) },
+                                                new[] { _sqlExpressionFactory.Constant(1), translatedInstance, translatedPattern, _sqlExpressionFactory.Constant(1) },
                                                 nullable: true,
                                                 argumentsPropagateNullability: new[] { false, true, true, false },
                                                 typeof(int)),

test/EFCore.Jet.FunctionalTests/GreenTests/ace_2010_odbc_x86.txt

@@ -7973,6 +7973,10 @@ EntityFrameworkCore.Jet.FunctionalTests.Query.FromSqlSprocQueryJetTest.From_sql_
 EntityFrameworkCore.Jet.FunctionalTests.Query.FromSqlSprocQueryJetTest.From_sql_queryable_with_multiple_stored_procedures_on_client(async: True)
 EntityFrameworkCore.Jet.FunctionalTests.Query.FromSqlSprocQueryJetTest.From_sql_queryable_with_multiple_stored_procedures(async: False)
 EntityFrameworkCore.Jet.FunctionalTests.Query.FromSqlSprocQueryJetTest.From_sql_queryable_with_multiple_stored_procedures(async: True)
+EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_contains_on_argument_with_wildcard_column_negated(isAsync: False)
+EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_contains_on_argument_with_wildcard_column_negated(isAsync: True)
+EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_contains_on_argument_with_wildcard_column(isAsync: False)
+EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_contains_on_argument_with_wildcard_column(isAsync: True)
 EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_contains_on_argument_with_wildcard_constant(isAsync: False)
 EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_contains_on_argument_with_wildcard_constant(isAsync: True)
 EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_ends_with_equals_nullable_column(isAsync: False)
@@ -7989,6 +7993,8 @@ EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_ends_
 EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_ends_with_on_argument_with_wildcard_column(isAsync: True)
 EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_ends_with_on_argument_with_wildcard_constant(isAsync: False)
 EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_ends_with_on_argument_with_wildcard_constant(isAsync: True)
+EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_FirstOrDefault_and_LastOrDefault(async: False)
+EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_FirstOrDefault_and_LastOrDefault(async: True)
 EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_starts_with_on_argument_with_wildcard_column_negated(isAsync: False)
 EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_starts_with_on_argument_with_wildcard_column_negated(isAsync: True)
 EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_starts_with_on_argument_with_wildcard_column(isAsync: False)

test/EFCore.Jet.FunctionalTests/GreenTests/ace_2010_oledb_x86.txt

@@ -9412,6 +9412,10 @@ EntityFrameworkCore.Jet.FunctionalTests.Query.FromSqlSprocQueryJetTest.From_sql_
 EntityFrameworkCore.Jet.FunctionalTests.Query.FromSqlSprocQueryJetTest.From_sql_queryable_with_multiple_stored_procedures_on_client(async: True)
 EntityFrameworkCore.Jet.FunctionalTests.Query.FromSqlSprocQueryJetTest.From_sql_queryable_with_multiple_stored_procedures(async: False)
 EntityFrameworkCore.Jet.FunctionalTests.Query.FromSqlSprocQueryJetTest.From_sql_queryable_with_multiple_stored_procedures(async: True)
+EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_contains_on_argument_with_wildcard_column_negated(isAsync: False)
+EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_contains_on_argument_with_wildcard_column_negated(isAsync: True)
+EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_contains_on_argument_with_wildcard_column(isAsync: False)
+EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_contains_on_argument_with_wildcard_column(isAsync: True)
 EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_contains_on_argument_with_wildcard_constant(isAsync: False)
 EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_contains_on_argument_with_wildcard_constant(isAsync: True)
 EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_contains_on_argument_with_wildcard_parameter(isAsync: False)
@@ -9432,6 +9436,8 @@ EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_ends_
 EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_ends_with_on_argument_with_wildcard_constant(isAsync: True)
 EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_ends_with_on_argument_with_wildcard_parameter(isAsync: False)
 EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_ends_with_on_argument_with_wildcard_parameter(isAsync: True)
+EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_FirstOrDefault_and_LastOrDefault(async: False)
+EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_FirstOrDefault_and_LastOrDefault(async: True)
 EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_starts_with_on_argument_with_bracket(isAsync: False)
 EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_starts_with_on_argument_with_bracket(isAsync: True)
 EntityFrameworkCore.Jet.FunctionalTests.Query.FunkyDataQueryJetTest.String_starts_with_on_argument_with_wildcard_column_negated(isAsync: False)

test/EFCore.Jet.FunctionalTests/Query/FunkyDataQueryJetTest.cs

@@ -140,10 +140,12 @@ FROM `FunkyCustomers` AS `f`
             await base.String_contains_on_argument_with_wildcard_column(isAsync);
 
             AssertSql(
-                $@"SELECT `f`.`FirstName` AS `fn`, `f0`.`LastName` AS `ln`
+                """
+SELECT `f`.`FirstName` AS `fn`, `f0`.`LastName` AS `ln`
 FROM `FunkyCustomers` AS `f`,
 `FunkyCustomers` AS `f0`
-WHERE (`f0`.`LastName` LIKE '') OR INSTR(1, `f`.`FirstName`, `f0`.`LastName`, 1) > 0");
+WHERE `f`.`FirstName` IS NOT NULL AND `f0`.`LastName` IS NOT NULL AND (INSTR(1, `f`.`FirstName`, `f0`.`LastName`, 1) > 0 OR (`f0`.`LastName` LIKE ''))
+""");
         }
 
         public override async Task String_contains_on_argument_with_wildcard_column_negated(bool isAsync)
@@ -151,10 +153,12 @@ WHERE (`f0`.`LastName` LIKE '') OR INSTR(1, `f`.`FirstName`, `f0`.`LastName`, 1)
             await base.String_contains_on_argument_with_wildcard_column_negated(isAsync);
 
             AssertSql(
-                $@"SELECT `f`.`FirstName` AS `fn`, `f0`.`LastName` AS `ln`
+                """
+SELECT `f`.`FirstName` AS `fn`, `f0`.`LastName` AS `ln`
 FROM `FunkyCustomers` AS `f`,
 `FunkyCustomers` AS `f0`
-WHERE NOT ((`f0`.`LastName` LIKE '') OR INSTR(1, `f`.`FirstName`, `f0`.`LastName`, 1) > 0)");
+WHERE NOT (`f`.`FirstName` IS NOT NULL AND `f0`.`LastName` IS NOT NULL AND (INSTR(1, `f`.`FirstName`, `f0`.`LastName`, 1) > 0 OR (`f0`.`LastName` LIKE '')))
+""");
         }
 
         public override async Task String_starts_with_on_argument_with_wildcard_constant(bool isAsync)

test/EFCore.Jet.FunctionalTests/Query/NorthwindFunctionsQueryJetTest.Functions.cs

@@ -294,7 +294,7 @@ WHERE MID(`c`.`ContactName`, 1, 1) = 'A'
                 """
 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 MID(`c`.`ContactName`, IIF(LEN(`c`.`ContactName`) IS NULL, 0, LEN(`c`.`ContactName`)), 1) = 's'
+WHERE MID(`c`.`ContactName`, IIF(IIF(LEN(`c`.`ContactName`) = 0, 1, LEN(`c`.`ContactName`)) IS NULL, 0, IIF(LEN(`c`.`ContactName`) = 0, 1, LEN(`c`.`ContactName`))), 1) = 's'
 """);
         }
 

test/EFCore.Jet.FunctionalTests/Query/NullSemanticsQueryJetTest.cs

@@ -1031,7 +1031,7 @@ WHERE `e`.`NullableStringC` <> IIF(`e`.`NullableStringA` = `e`.`NullableStringB`
                 """
 SELECT `e`.`Id`
 FROM `Entities1` AS `e`
-WHERE `e`.`NullableStringA` IS NOT NULL AND `e`.`NullableStringB` IS NOT NULL AND (INSTR(1, `e`.`NullableStringB`, `e`.`NullableStringA`, 1) > 0 OR (`e`.`NullableStringB` LIKE '')) AND `e`.`BoolA` = TRUE
+WHERE `e`.`NullableStringA` IS NOT NULL AND `e`.`NullableStringB` IS NOT NULL AND (INSTR(1, `e`.`NullableStringA`, `e`.`NullableStringB`, 1) > 0 OR (`e`.`NullableStringB` LIKE '')) AND `e`.`BoolA` = TRUE
 """);
         }
 
@@ -1808,10 +1808,10 @@ FROM `Entities1` AS `e`
             await base.Nullable_string_FirstOrDefault_compared_to_nullable_string_LastOrDefault(async);
 
             AssertSql(
-            """
+                """
 SELECT `e`.`Id`, `e`.`BoolA`, `e`.`BoolB`, `e`.`BoolC`, `e`.`IntA`, `e`.`IntB`, `e`.`IntC`, `e`.`NullableBoolA`, `e`.`NullableBoolB`, `e`.`NullableBoolC`, `e`.`NullableIntA`, `e`.`NullableIntB`, `e`.`NullableIntC`, `e`.`NullableStringA`, `e`.`NullableStringB`, `e`.`NullableStringC`, `e`.`StringA`, `e`.`StringB`, `e`.`StringC`
 FROM `Entities1` AS `e`
-WHERE MID(`e`.`NullableStringA`, 1, 1) = MID(`e`.`NullableStringB`, IIF(LEN(`e`.`NullableStringB`) IS NULL, 0, LEN(`e`.`NullableStringB`)), 1) OR (`e`.`NullableStringA` IS NULL AND `e`.`NullableStringB` IS NULL)
+WHERE MID(`e`.`NullableStringA`, 1, 1) = MID(`e`.`NullableStringB`, IIF(IIF(LEN(`e`.`NullableStringB`) = 0, 1, LEN(`e`.`NullableStringB`)) IS NULL, 0, IIF(LEN(`e`.`NullableStringB`) = 0, 1, LEN(`e`.`NullableStringB`))), 1) OR (`e`.`NullableStringA` IS NULL AND `e`.`NullableStringB` IS NULL)
 """);
         }