/// <summary>
/// Get data from a child table based on the relation name and the primary key's fieldValue from the parent table.
/// </summary>
/// <param name="primaryKeyValue">The fieldValue of the primary key</param>
/// <returns>The selected TableMetadata </returns>
public TableMetadata GetTableMetadata(object primaryKeyValue)
{
SqlGenerator generator = new SqlGenerator();
DataFactory factory = new DataFactory();
//generate select statement
if (primaryKeyValue == null)
{
throw new ArgumentException("Invalid fieldValue for primary key");
}
ISqlGenerator isql = factory.InitializeSqlGenerator(database);
DatabaseField pkField = mappedObject.GetPrimaryKeyField();
pkField.fieldValue = primaryKeyValue;
//generate select query
ExecutionQuery selectQuery = generator.GenerateSelectQuery(database, mappedObject.TableName, mappedObject.TableFields, pkField);
TableMetadata table = (TableMetadata)Activator.CreateInstance(mappedObject.GetType());
ArrayList alList = MapDataReaderToTableMetadata(selectQuery, table);
table = (TableMetadata)alList[0];
return(table);
}
/// <summary>
/// Converts data from a DataTable to TableMetadata array. The scheme of the DataTable
/// must be the same with that of the TableMetadata.
/// </summary>
/// <param name="table">DataTable which contains the data </param>
/// <param name="metadata">Type of TableMetadata</param>
/// <returns>TableMetadata array which holds the converted items</returns>
public Array ConvertToTableMatadata(DataTable table, TableMetadata metadata)
{
Array arr = Array.CreateInstance(metadata.GetType(), table.Rows.Count);
for (int i = 0; i < table.Rows.Count; i++)
{
TableMetadata meta = (TableMetadata)Activator.CreateInstance(metadata.GetType());
for (int j = 0; j < table.Columns.Count; j++)
{
meta.SetFieldValue(table.Columns[j].ColumnName, table.Rows[i][j]);
}
arr.SetValue(meta, i);
}
return(arr);
}
/// <summary>
/// Maps a DataReader to a TableMetadata implementation.
/// </summary>
/// <param name="selectQuery">The ExecutionQuery</param>
/// <param name="table">TableMetadata on which the query results will be mapped </param>
/// <returns>ArrayList with TableMetadata results</returns>
internal ArrayList MapDataReaderToTableMetadata(ExecutionQuery selectQuery, TableMetadata table)
{
IDataReader iread = null;
ArrayList alTables = null;
ExecutionEngine exec = null;
try
{
alTables = new ArrayList();
//check if we run it in the context session
if (contextSession != null)
{
iread = execEngine.ExecuteReader(selectQuery);
}
else
{
exec = new ExecutionEngine();
iread = exec.ExecuteReader(database, connectionString, selectQuery);
}
int columnCount = iread.FieldCount;
while (iread.Read())
{
//create a instance of the table metadata
TableMetadata tempTable = (TableMetadata)Activator.CreateInstance(table.GetType());
//set the field's fieldValue
for (int i = 0; i < columnCount; i++)
{
//tempTable.SetFieldValue(tempTable.TableFields[i].fieldName, iread.GetValue(i));
tempTable.SetFieldValue(i, iread.GetValue(i));
}
alTables.Add(tempTable);
}
iread.Close();
return(alTables);
}
finally
{
if (iread != null && iread.IsClosed == false)
{
iread.Close();
}
if (exec != null)
{
exec.Dispose();
}
}
}
