Fixed composite foreign keys bug (Issue 885) (#977)

* Fixed composite foreign keys bug

* Update Generator.cs

Inverted condition and add spacing

* Added test for scripting of composite foreign keys

* Changed primary key value to avoid testing unique constraint

src/API/Generator/Generator.cs

@@ -1604,10 +1604,10 @@ private void GenerateTriggerForForeignKey(string prefix, string triggerType, Con
 
             if (column.IsNullable == YesNoOption.YES)
             {
-                _sbScript.Append(string.Join(" ", constraint.Columns.Select(x => $"NEW.{x} IS NOT NULL AND").ToArray()));
+                _sbScript.Append(string.Join("", constraint.Columns.Select(x => $"NEW.{x} IS NOT NULL AND ").ToArray()));
             }
 
-            _sbScript.Append($"(SELECT {string.Join(", ", constraint.UniqueColumns.ToArray())} FROM {foreignTableName} WHERE ");
+            _sbScript.Append($"NOT EXISTS (SELECT * FROM {foreignTableName} WHERE ");
 
             for (int i = 0; i < constraint.Columns.Count; i++)
             {
@@ -1627,7 +1627,7 @@ private void GenerateTriggerForForeignKey(string prefix, string triggerType, Con
                 }
             }
 
-            _sbScript.Append(") IS NULL;");
+            _sbScript.Append(");");
             _sbScript.AppendLine(" END;");
         }
 
@@ -2335,4 +2335,4 @@ private void GenerateTrigger(Trigger trigger)
         }
         #endregion
     }
-}
+}

src/API/SqlCeScripting40/Tests/GeneratorTest/Test.cs

@@ -4,7 +4,10 @@
 using System;
 using System.Collections.Generic;
 using System.Data.SqlClient;
+using System.Data.SQLite;
+using System.Data.SqlServerCe;
 using System.IO;
+using System.Linq;
 using System.Text;
 using System.Text.RegularExpressions;
 
@@ -116,6 +119,53 @@ public void TestServerExportToSqlite()
             }
         }
 
+        [Test]
+        public void TestCompactExportToSqliteCompositeForeignKey()
+        {
+            // Script SQL CE DB with composite foreign key
+            var sourceConnectionString = new SqlCeConnectionStringBuilder
+            {
+                DataSource = Path.Combine(dbPath, "composite_foreign_key.sdf"),
+                MaxDatabaseSize = 4091
+            }.ToString();
+            var path = @"C:\temp\composite_foreign_key.sql";
+
+            IList<string> generatedFiles;
+            using (var sourceRepository = new DB4Repository(sourceConnectionString))
+            {
+                var generator = new Generator4(sourceRepository, path, false, false, true);
+                generator.ScriptDatabaseToFile(Scope.SchemaDataSQLite);
+                generatedFiles = generator.GeneratedFiles.ToList();
+            }
+
+            // Generate SQLite DB and test data insertion
+            var targetConnectionString = new SQLiteConnectionStringBuilder
+            {
+                DataSource = ":memory:",
+                Version = 3
+            }.ToString();
+            using (var targetRepository = new SQLiteRepository(targetConnectionString))
+            {
+                foreach (var generatedFile in generatedFiles)
+                {
+                    targetRepository.ExecuteSqlFile(generatedFile);
+                }
+
+                // The owner table has only one entry with ID (0, 0)
+                targetRepository.ExecuteSql(
+                    "INSERT INTO [Product] (ProductId, OwnerId1, OwnerId2) Values (0, 0, 0); GO;");
+                Assert.Throws<SQLiteException>(() =>
+                    targetRepository.ExecuteSql(
+                        "INSERT INTO [Product] (ProductId, OwnerId1, OwnerId2) Values (1, 0, 1); GO;"));
+                Assert.Throws<SQLiteException>(() =>
+                    targetRepository.ExecuteSql(
+                        "INSERT INTO [Product] (ProductId, OwnerId1, OwnerId2) Values (2, 1, 0); GO;"));
+                Assert.Throws<SQLiteException>(() =>
+                    targetRepository.ExecuteSql(
+                        "INSERT INTO [Product] (ProductId, OwnerId1, OwnerId2) Values (3, 1, 1); GO;"));
+            }
+        }
+
         [Test]
         public void TestServerExportDotInTable()
         {

src/API/SqlCeScripting40/Tests/Tests.csproj

@@ -127,6 +127,11 @@
       <CopyToOutputDirectory>Always</CopyToOutputDirectory>
     </None>
   </ItemGroup>
+  <ItemGroup>
+    <Content Include="composite_foreign_key.sdf">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </Content>
+  </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
     <PropertyGroup>