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PObusiness service calls multiple methods on the Data Access Layer each opening a connection
 

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  1. PObusiness service calls multiple methods on the Data Access Layer each opening a connection
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    <p>I am doing this pseudo-code in my unitservice which is calling 2 methods of the UnitDataProvider class.</p> <pre><code>var units = dataProvider.GetChildrenUnits(parentId); unit.HierarchyIndex = units.Where( u =&gt; u.TemplateId == unit.TemplateId &amp;&amp; u.ParentId == null).Max( u =&gt; u.HierarchyIndex) + 1; dataProvider.AddSiblingUnit(unit); </code></pre> <p>Every method opens a connection.</p> <p>How could this be refactorized to use only 1 connection or reuse an open connection?</p> <p>Or do you think its normal to a connection for each dataprovider method call?</p> <p>SOLUTION: all data access logic on the database is done within the DAL not the BLL as I think the below is NO business logic for my business its just database logic.</p> <pre><code>public void AddSiblingUnit(Unit unit) { if (unit.ParentId == null) { throw new OnlyOneRootNodeIsAllowedException("Only one Root node is allowed!", null); } // Server side check if the root is selected because 2 root units are not allowed lock (_lockObject) { using (var trans = new TransactionScope()) using (var con = new SqlConnection(_connectionString)) using (var cmd = new SqlCommand()) { cmd.Connection = con; con.Open(); // SELECT HierarchyIndex for the new inserted sibling string selectCommandText = "SELECT HierarchyIndex FROM UNIT WHERE UnitId = @UnitId"; // UnitId of the selected sibling cmd.CommandText = selectCommandText; cmd.Parameters.AddWithValue("UnitId", unit.UnitId); // the parentId which is the selected UnitId int hierarchyIndexOfSelectedSibling = Convert.ToInt32(cmd.ExecuteScalar()); int hierarchyIndexOfNewSibling = hierarchyIndexOfSelectedSibling + 1; // UPDATE all sibling units whose HierarchyIndex is greater than the HierarchyIndex of the selected sibling string updateCommandText = "UPDATE UNIT SET HierarchyIndex = HierarchyIndex + 1 WHERE HierarchyIndex &gt;= @HierarchyIndex AND ParentId = @ParentId"; cmd.CommandText = updateCommandText; cmd.Parameters.AddWithValue("HierarchyIndex", hierarchyIndexOfNewSibling); cmd.Parameters.AddWithValue("ParentId", unit.ParentId); cmd.ExecuteNonQuery(); // INSERT new sibling string insertCommandText = "INSERT INTO UNIT (Name,TemplateId,CreatedAt,HierarchyIndex,ParentId) VALUES (@Name,@TemplateId,@CreatedAt,@HierarchyIndex,@ParentId);Select Scope_Identity();"; cmd.CommandText = insertCommandText; cmd.Parameters.AddWithValue("Name", unit.Name); cmd.Parameters.AddWithValue("TemplateId", unit.TemplateId); cmd.Parameters.Add("CreatedAt", SqlDbType.DateTime2).Value = unit.CreatedAt; unit.UnitId = Convert.ToInt32(cmd.ExecuteScalar()); trans.Complete(); } } } </code></pre>
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