/// <summary>
/// Get a Datapoint from the database by its ID
/// </summary>
/// <returns>
/// The DatapointNode instance or
/// NULL if no datapoint node is present in the datbase
/// </returns>
public DatapointNode GetDatapointNodeByID(Int64 NodeID)
{
// Read the row with from the databse with the given ID
ObjectTreeRow NodeRow = this.GetNodeByID(NodeID);
// If there is no such row in the database return null
if (NodeRow == null)
{
return(null);
}
// If there is such a row in the datbase create and return a DatapointNode Instance
return(new DatapointNode(NodeRow));
}
/// <summary>
/// A row of the object_tree table
/// </summary>
/// <param name="NodeID">
/// ID of the row in the database
/// </param>
/// <returns>
/// A ObjectTreeRow instance that represents the database row or
/// NULL if the row is not present in the datbase
/// </returns>
private ObjectTreeRow GetNodeByID(Int64 NodeID)
{
// Command that will be send to the databse
MySqlCommand Command = this.Connection.CreateCommand();
// Reader to read the database answer
MySqlDataReader Reader;
// Get the row (tuple) from the datbase with a specific id
// SELECT * > Get all columns of the table
// FROM object_tree > Target table object_tree
// WHERE object_id = {0} > Get all rows where the column object_id matches the given id
// LIMIT 1 > Because the id is unique we can limit it to 1 row
Command.CommandText = String.Format("SELECT * FROM object_tree WHERE object_id = {0} LIMIT 1", NodeID);
Command.Connection = this.Connection;
// Represents a row (tuple) of the object_tree table
ObjectTreeRow NodeRow = null;
// Execute the command and read the answer
Reader = Command.ExecuteReader();
// Read the answer
while (Reader.Read())
{
string row = "";
for (int i = 0; i < (Reader.FieldCount); i++)
{
row += Reader.GetValue(i).ToString() + ",";
}
NodeRow = new ObjectTreeRow(row.Substring(0, row.Length - 1));
}
Reader.Close();
// When there is no answer from the database (e.g. there is no row with the specific id) return null
if (NodeRow == null)
{
return(null);
}
// Return the object that represents a row (tuple) of the object_tree table
// Important: It is no Node Instance, that mean you have to create the corresponding Node Instance in a further step
return(NodeRow);
}
/// <summary>
/// Get the root node from the database
/// </summary>
/// <returns>
/// The RootNode Instance or
/// NULL if no root node is present in the datbase
/// </returns>
public RootNode GetRootNode()
{
// Command that will be send to the databse
MySqlCommand Command = this.Connection.CreateCommand();
// Reader to read the database answer
MySqlDataReader Reader;
// There can obly be one!!! root node so we can get the root node by the object type
// SELECT * > Get all columns of the table
// FROM object_tree > Target table object_tree
// WHERE object_type = {0} > Get all rows where the column object_type matches the given id
// LIMIT 1 > Because the id is unique we can limit it to 1 row
Command.CommandText = "SELECT * FROM object_tree WHERE object_type = 1 LIMIT 1";
Command.Connection = this.Connection;
// Represents a row (tuple) of the object_tree table
ObjectTreeRow RootNodeRow = null;
// Execute the command and read the answer
Reader = Command.ExecuteReader();
// Read the answer
while (Reader.Read())
{
string row = "";
for (int i = 0; i < (Reader.FieldCount - 1); i++)
{
row += Reader.GetValue(i).ToString() + ",";
}
RootNodeRow = new ObjectTreeRow(row);
}
Reader.Close();
// When there is no answer from the database (e.g. there is no node root node) return null
if (RootNodeRow == null)
{
return(null);
}
// Return the found root node as an RootNode Instance
return(new RootNode(RootNodeRow));
}
public List <AbstractObjectNode> GetAllAbstractNodes()
{
// A list of all nodes in the database
List <AbstractObjectNode> nodeList = new List <AbstractObjectNode>();
// Command that will be send to the databse
MySqlCommand Command = this.Connection.CreateCommand();
// Reader to read the database answer
MySqlDataReader Reader;
// Get the row (tuple) from the datbase with a specific id
// SELECT * > Get all columns of the table
// FROM object_tree > Target table object_tree
// WHERE object_id = {0} > Get all rows where the column object_id matches the given id
// LIMIT 1 > Because the id is unique we can limit it to 1 row
Command.CommandText = "SELECT * FROM object_tree ORDER BY object_name";
Command.Connection = this.Connection;
// Represents a row (tuple) of the object_tree table
ObjectTreeRow NodeRow = null;
// Execute the command and read the answer
Reader = Command.ExecuteReader();
// Read the answer
while (Reader.Read())
{
string row = "";
for (int i = 0; i < (Reader.FieldCount - 1); i++)
{
row += Reader.GetValue(i).ToString() + ",";
}
// RootNode = AbstracObjectNode
nodeList.Add(new RootNode(new ObjectTreeRow(row)));
}
Reader.Close();
// Return the list with all nodes
return(nodeList);
}
