/// <summary>
/// Fetches the IDs of rows that are associated to the panel`s datarow through a maptable and edited in a M2NMappingField
/// </summary>
/// <param name="mapping"></param>
/// <param name="key"></param>
/// <returns></returns>
private List <int> FetchMappingValues(M2NMapping mapping, int key)
{
DataTable tbl = driver.fetchAll("SELECT", dbe.Col(mapping.mapRefColumn), "FROM", dbe.Table(mapping.mapTable), "WHERE", dbe.Col(mapping.mapMyColumn), " = ", dbe.InObj(key));
List <int> res = new List <int>();
foreach (DataRow r in tbl.Rows)
{
res.Add((int)(r[0]));
}
return(res);
}
/// <summary>
/// INSERTs rows neccessary for mapping the inserted / updated datarow to another table via a M2NMappingField. Does not clear the mapping by itself
/// => UnmapM2NMappingKey must be called on update
/// </summary>
/// <param name="mapping"></param>
/// <param name="key"></param>
/// <param name="vals"></param>
private void MapM2NVals(M2NMapping mapping, int key, List <int> vals)
{
DataTable table = new DataTable();
table.Columns.Add(mapping.mapMyColumn, typeof(int));
table.Columns.Add(mapping.mapRefColumn, typeof(int));
DataRow row = table.NewRow();
foreach (int val in vals)
{
row[0] = key;
row[1] = val;
driver.query("INSERT INTO", mapping.mapTable, dbe.InsVals(row));
}
}
/// <summary>
/// Deletes the row determined by the panel`s PK from the panl`s table.
/// Also clears the mapping (this may not be neccessary if the constraint CASCADEs, but it is probably the desired behaviour in either case).
/// </summary>
/// <param name="panel"></param>
public void DeleteFromPanel(Panel panel)
{
driver.BeginTransaction();
foreach (IField f in panel.fields)
{
if (f is M2NMappingField)
{
M2NMapping mapping = ((M2NMappingField)f).Mapping;
UnmapM2NMappingKey(mapping, (int)(panel.PK[mapping.mapMyColumn]));
}
}
int affected = driver.query("DELETE FROM", dbe.Table(panel.tableName), " WHERE", dbe.Condition(panel.PK));
if (affected > 1)
{
driver.RollbackTransaction();
throw new Exception("Panel PK not unique, trying to delete more rows at a time!");
}
driver.CommitTransaction();
}
private void UnmapM2NMappingKey(M2NMapping mapping, int key)
{
driver.query("DELETE FROM", dbe.Table(mapping.mapTable), "WHERE", dbe.Col(mapping.mapMyColumn), " = ", key);
}
public M2NMappingField(M2NMapping mapping, string caption)
: base(caption)
{
this.Mapping = mapping;
}
