Add sequence reset for Oracle

Respawn.DatabaseTests/OracleTests.cs

@@ -1,6 +1,5 @@
 using Xunit.Abstractions;
 
-#if ORACLE
 namespace Respawn.DatabaseTests
 {
     using System;
@@ -476,6 +475,26 @@ public async Task ShouldIncludeSchemas()
             await DropUser(userB);
         }
 
+        [SkipOnCI]
+        public async Task ShouldResetSequences()
+        {
+            await _database.ExecuteAsync("create table \"foo\" (value int, primary key (value))");
+            await _database.ExecuteAsync("CREATE SEQUENCE id_seq INCREMENT BY 1");
+            await _database.ExecuteScalarAsync<int>("select id_seq.nextval from dual");
+            await _database.ExecuteScalarAsync<int>("select id_seq.nextval from dual");
+            await _database.ExecuteScalarAsync<int>("select id_seq.nextval from dual");
+
+            var respawner = await Respawner.CreateAsync(_connection, new RespawnerOptions
+            {
+                DbAdapter = DbAdapter.Oracle,
+                SchemasToInclude = new[] { _createdUser },
+                WithReseed = true
+            });
+            await respawner.ResetAsync(_connection);
+
+            (await _database.ExecuteScalarAsync<int>("select id_seq.nextval from dual")).ShouldBe(1);
+        }
+
         private static async Task CreateUser(string userName)
         {
             using (var connection = new OracleConnection("Data Source=(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=localhost)(PORT=10521))(CONNECT_DATA=(SID=xe)));User Id=system;Password=oracle;"))
@@ -538,4 +557,3 @@ public async Task DisposeAsync()
         }
     }
 }
-#endif

Respawn/OracleDbAdapter.cs

@@ -1,8 +1,8 @@
-using System.Collections.Generic;
+using Respawn.Graph;
+using System.Collections.Generic;
 using System.Data.Common;
 using System.Linq;
 using System.Threading.Tasks;
-using Respawn.Graph;
 
 namespace Respawn
 {
@@ -191,14 +191,30 @@ private static IEnumerable<string> BuildCommands(GraphBuilder graph)
                 yield return $"EXECUTE IMMEDIATE 'ALTER TABLE {rel.ParentTable.GetFullName(QuoteCharacter)} ENABLE CONSTRAINT {QuoteCharacter}{rel.Name}{QuoteCharacter}';";
             }
         }
-        public string BuildReseedSql(IEnumerable<Table> tablesToDelete) => throw new System.NotImplementedException();
+
+        public string BuildReseedSql(IEnumerable<Table> tablesToDelete)
+        {
+            return @"
+                DECLARE
+                    sql_txt	VARCHAR2 (1000);
+                BEGIN
+                    FOR  s  IN  (select sequence_name, min_value from user_sequences)
+                    LOOP	                
+
+    	                sql_txt := 'ALTER SEQUENCE ' || s.sequence_name || ' restart start with ' || s.min_value;
+
+    	                EXECUTE IMMEDIATE sql_txt;
+	                END LOOP;
+                END;
+            ";
+        }
 
         public string BuildTemporalTableCommandText(RespawnerOptions options) => throw new System.NotImplementedException();
 
         public string BuildTurnOffSystemVersioningCommandText(IEnumerable<TemporalTable> tablesToTurnOffSystemVersioning) => throw new System.NotImplementedException();
 
         public string BuildTurnOnSystemVersioningCommandText(IEnumerable<TemporalTable> tablesToTurnOnSystemVersioning) => throw new System.NotImplementedException();
-        
+
         public Task<bool> CheckSupportsTemporalTables(DbConnection connection)
         {
             return Task.FromResult(false);