Fixes SQL providers for returning the correct results for constraints

src/Umbraco.Core/Persistence/SqlSyntax/SqlServerSyntaxProvider.cs

@@ -88,6 +88,7 @@ namespace Umbraco.Core.Persistence.SqlSyntax
                                    item.IS_NULLABLE, item.DATA_TYPE)).ToList();
         }
 
+        /// <inheritdoc />
         public override IEnumerable<Tuple<string, string>> GetConstraintsPerTable(Database db)
         {
             var items =
@@ -96,6 +97,7 @@ namespace Umbraco.Core.Persistence.SqlSyntax
             return items.Select(item => new Tuple<string, string>(item.TABLE_NAME, item.CONSTRAINT_NAME)).ToList();
         }
 
+        /// <inheritdoc />
         public override IEnumerable<Tuple<string, string, string>> GetConstraintsPerColumn(Database db)
         {
             var items =
@@ -104,6 +106,7 @@ namespace Umbraco.Core.Persistence.SqlSyntax
             return items.Select(item => new Tuple<string, string, string>(item.TABLE_NAME, item.COLUMN_NAME, item.CONSTRAINT_NAME)).ToList();
         }
 
+        /// <inheritdoc />
         public override IEnumerable<Tuple<string, string, string, bool>> GetDefinedIndexes(Database db)
         {
             var items =
@@ -113,7 +116,7 @@ CASE WHEN I.is_unique_constraint = 1 OR  I.is_unique = 1 THEN 1 ELSE 0 END AS [U
 from sys.tables as T inner join sys.indexes as I on T.[object_id] = I.[object_id] 
    inner join sys.index_columns as IC on IC.[object_id] = I.[object_id] and IC.[index_id] = I.[index_id] 
    inner join sys.all_columns as AC on IC.[object_id] = AC.[object_id] and IC.[column_id] = AC.[column_id] 
-WHERE I.name NOT LIKE 'PK_%'
+WHERE I.is_primary_key = 0
 order by T.name, I.name");
             return items.Select(item => new Tuple<string, string, string, bool>(item.TABLE_NAME, item.INDEX_NAME, item.COLUMN_NAME,
                 item.UNIQUE == 1)).ToList();
@@ -183,4 +186,4 @@ order by T.name, I.name");
 
 
     }
-}
+}