/// <summary>
/// Invoked to retrieve the next available record produced by the execution of the
/// enumerable command, or null if there are no more records available.
/// </summary>
internal Core.IRecord OnReaderNext()
{
Core.IRecord record = null;
try
{
if (_DataReader.Read())
{
record = new Core.Concrete.Record(_Schema);
for (int i = 0; i < _Schema.Count; i++)
{
record[i] = _DataReader.IsDBNull(i) ? null : _DataReader.GetValue(i);
}
return(record);
}
else
{
OnDispose(true); return(null);
}
}
catch (Exception e)
{
try { OnDispose(true); }
catch { }
throw e;
}
}
/// <summary>
/// Returns an ad-hoc record containing the changes experimented by the entity since the
/// last time its internal record was captured, or null if no changes can be detected.
/// </summary>
internal static IRecord GetRecordChanges(this MetaEntity meta)
{
object obj = meta.Entity; if (obj == null)
{
return(null);
}
if (meta.UberMap == null)
{
return(null);
}
if (meta.Record == null)
{
return(null);
}
var current = new Core.Concrete.Record(meta.UberMap.Schema);
meta.UberMap.WriteRecord(obj, current);
var changes = current.Changes(meta.Record); current.Dispose();
return(changes);
}
/// <summary>
/// Generates a delete core command for the given entity, or returns null if such
/// command cannot be generated for whatever reasons.
/// </summary>
internal static IDeleteCommand GenerateDeleteCommand(this IUberMap map, object entity)
{
if (entity == null)
{
return(null);
}
if (map == null || map.IsDisposed || !map.IsValidated)
{
return(null);
}
IDeleteCommand cmd = null;
MetaEntity meta = MetaEntity.Locate(entity, create: true); if (meta.Record == null)
{
var record = new Core.Concrete.Record(map.Schema);
map.WriteRecord(entity, record);
meta.Record = record;
}
var id = map.ExtractId(meta.Record);
if (id != null)
{
cmd = map.Link.Engine.CreateDeleteCommand(map.Link, x => map.Table);
if (map.Discriminator != null)
{
cmd.Where(map.Discriminator);
}
var tag = new DynamicNode.Argument("x");
for (int i = 0; i < id.Count; i++)
{
var left = new DynamicNode.GetMember(tag, id.Schema[i].ColumnName);
var bin = new DynamicNode.Binary(left, ExpressionType.Equal, id[i]);
cmd.Where(x => bin);
left.Dispose();
bin.Dispose();
}
tag.Dispose();
id.Dispose();
}
return(cmd);
}
/// <summary>
/// Generates an insert core command for the given entity, or returns null if such
/// command cannot be generated for whatever reasons.
/// </summary>
internal static IInsertCommand GenerateInsertCommand(this IUberMap map, object entity)
{
if (entity == null)
{
return(null);
}
if (map == null || map.IsDisposed || !map.IsValidated)
{
return(null);
}
IInsertCommand cmd = null;
int num = map.Schema.Count(x => !x.IsReadOnlyColumn);
if (num != 0)
{
cmd = map.Link.Engine.CreateInsertCommand(map.Link, x => map.Table);
var tag = new DynamicNode.Argument("x");
var rec = new Core.Concrete.Record(map.Schema); map.WriteRecord(entity, rec);
for (int i = 0; i < rec.Count; i++)
{
if (rec.Schema[i].IsReadOnlyColumn)
{
continue;
}
var node = new DynamicNode.SetMember(tag, rec.Schema[i].ColumnName, rec[i]);
cmd.Columns(x => node);
node.Dispose();
}
tag.Dispose();
rec.Dispose();
}
return(cmd);
}
/// <summary>
/// Returns the id string associated with the given entity, generating it if needed.
/// Returns null if it cannot be generated if needed or, optionally, raises an exception.
/// Optionally captures the state in a new record if it did not exist previously.
/// </summary>
string LocateId(MetaEntity meta, bool raise, bool captureRecord)
{
var str = meta.CollectionId;
if (str != null)
{
return(str);
}
var obj = meta.Entity;
if (obj == null)
{
throw new InvalidOperationException("MetaEntity '{0}' is invalid.".FormatWith(meta));
}
var record = meta.Record; if (record == null)
{
record = new Core.Concrete.Record(_Master.Schema);
_Master.WriteRecord(obj, record);
}
str = GenerateId(record, raise);
if (meta.Record == null)
{
if (captureRecord)
{
meta.Record = record;
}
else
{
record.Dispose();
}
}
return(str);
}
/// <summary>
/// Generates an update core command for the given entity, or returns null if such
/// command cannot be generated for whatever reasons.
/// </summary>
internal static IUpdateCommand GenerateUpdateCommand(this IUberMap map, object entity)
{
if (entity == null)
{
return(null);
}
if (map == null || map.IsDisposed || !map.IsValidated)
{
return(null);
}
IUpdateCommand cmd = null;
MetaEntity meta = MetaEntity.Locate(entity, create: true); if (meta.Record == null)
{
var record = new Core.Concrete.Record(map.Schema);
map.WriteRecord(entity, record);
meta.Record = record;
}
var changes = meta.GetRecordChanges(); if (changes == null)
{
return(null);
}
var num = changes.Schema.Count(x => !x.IsReadOnlyColumn);
if (num != 0)
{
var id = map.ExtractId(meta.Record); if (id != null)
{
cmd = map.Link.Engine.CreateUpdateCommand(map.Link, x => map.Table);
if (map.Discriminator != null)
{
cmd.Where(map.Discriminator);
}
var tag = new DynamicNode.Argument("x");
for (int i = 0; i < id.Count; i++)
{
var left = new DynamicNode.GetMember(tag, id.Schema[i].ColumnName);
var bin = new DynamicNode.Binary(left, ExpressionType.Equal, id[i]);
cmd.Where(x => bin);
left.Dispose();
bin.Dispose();
}
for (int i = 0; i < changes.Count; i++)
{
if (changes.Schema[i].IsReadOnlyColumn)
{
continue;
}
var node = new DynamicNode.SetMember(tag, changes.Schema[i].ColumnName, changes[i]);
cmd.Columns(x => node);
node.Dispose();
}
tag.Dispose();
id.Dispose();
}
}
changes.Dispose(disposeSchema: true);
return(cmd);
}
/// <summary>
/// Invoked to retrieve the next available record produced by the execution of the
/// enumerable command, or null if there are no more records available.
/// </summary>
internal Core.IRecord OnReaderNext()
{
Core.IRecord record = null;
try
{
if (_DataReader.Read())
{
record = new Core.Concrete.Record(_Schema);
for (int i = 0; i < _Schema.Count; i++)
record[i] = _DataReader.IsDBNull(i) ? null : _DataReader.GetValue(i);
return record;
}
else
{
OnDispose(true); return null;
}
}
catch (Exception e)
{
try { OnDispose(true); }
catch { }
throw e;
}
}
