public T Load <T>(object entityObj, ref T loadTo, [CallerMemberName] string name = "")
{
if (!ShouldLoad(loadTo, name))
{
return(loadTo);
}
var attribute = _entity.Attributes[name];
var fkAttr = attribute.Relation.FromKeyAttribute;
var otherEntity = _context.Schema.EntityTypeMap[typeof(T)];
var fk = _entry.ShadowAttributes[fkAttr.Name];
var query = new QueryBuilder(_context)
.Select <T>()
.Where(new WhereSqlFragment(
BinaryExpression.Eq(
new Accessor
{
PropertyName = attribute.Relation.ToKeyAttribute.DataBaseColumn,
TableName = otherEntity.TableName
},
Value.FromAttr(fk, fkAttr)
))).Build();
var loaded = _context.Connection.Select(query).First();
loadTo = loaded;
_entry.OriginalValues[attribute.Name] = loaded;
_attributeGenerations[name] = _context.ChangeTracker.Generation;
return(loaded);
}
/// <summary>
/// Finds a specific entity with the given primary key, returns null is the given key was not found
/// </summary>
/// <param name="primaryKey"></param>
/// <returns></returns>
public T Find(object primaryKey)
{
var entity = _ctx.Schema.EntityTypeMap[typeof(T)];
var pkAttr = entity.PrimaryKeyAttribute;
var filter = new WhereSqlFragment(
BinaryExpression.Eq(
new Accessor
{
PropertyName = pkAttr.DataBaseColumn,
TableName = entity.TableName
}, Value.FromAttr(primaryKey, pkAttr)));
var query = new QueryBuilder(_ctx)
.Select <T>()
.Where(filter)
.Build();
return(_ctx.Connection.Select(query).FirstOrDefault());
}
public ICollection <T> Load <T>(object entityObj, ref ICollection <T> loadTo, [CallerMemberName] string name = "")
{
if (!ShouldLoad(loadTo, name))
{
return(loadTo);
}
var propAttr = _entity.Attributes[name];
var otherEntity = _context.Schema.EntityTypeMap[typeof(T)];
if (propAttr.Relation is ManyToMany relation)
{
return(LoadManyToMany(entityObj, ref loadTo, name, relation));
}
var attribute = _entity.Attributes[name];
var fkAttr = attribute.Relation.ToKeyAttribute;
var pkAttr = attribute.Relation.FromKeyAttribute;
var pk = pkAttr.InvokeGetter(entityObj);
var otherPk = attribute.Relation.ToEntity.PrimaryKeyAttribute;
var query = new QueryBuilder(_context)
.Select <T>()
.Where(new WhereSqlFragment(BinaryExpression.Eq(
new Accessor {
PropertyName = fkAttr.DataBaseColumn, TableName = otherEntity.TableName
},
Value.FromAttr(pk, pkAttr)
))).Build();
var loaded = _context.Connection.Select(query).ToList();
loadTo = loaded;
_entry.ReplaceRelatedKeys(attribute,
loaded.Select(obj => otherPk.InvokeGetter(obj)).ToList()
);
_attributeGenerations[name] = _context.ChangeTracker.Generation;
return(loadTo);
}
private ICollection <T> LoadManyToMany <T>(object entityObj, ref ICollection <T> loadTo, string propertyName,
ManyToMany relation)
{
var propAttr = _entity.Attributes[propertyName];
var otherEntity = _context.Schema.EntityTypeMap[typeof(T)];
var thisEntity = _context.Schema.EntityTypeMap[typeof(T)];
var betweenEntity = relation.BetweenEntity;
//student.id
var otherEntityPkAttr = relation.ToKeyAttribute;
//fk_student
var otherEntityFkAttr = relation.ReferencedToAttribute;
//Students
var fromEntityAttribute = relation.FromEntityAttribute;
var pk = relation.FromKeyAttribute.InvokeGetter(entityObj);
var query = new SelectQueryBuilder(_context)
.FromTable <T>(thisEntity.TableName)
.Join(betweenEntity, otherEntityPkAttr, otherEntityFkAttr)
.Select(otherEntity.Attributes.Values
.Where(attr => !attr.IsEntityType)
.Select(attr => attr.DataBaseColumn))
.Where(new WhereSqlFragment(
BinaryExpression.Eq(new Accessor
{
PropertyName = relation.ReferencedFromAttribute.DataBaseColumn,
TableName = betweenEntity.TableName
}, Value.FromAttr(pk, relation.FromKeyAttribute))))
.Build();
var loaded = _context.Connection.Select(query).ToList();
loadTo = loaded;
_entry.ReplaceRelatedKeys(propAttr, loaded.Select(obj =>
otherEntity.PrimaryKeyAttribute.InvokeGetter(obj)).ToList());
_attributeGenerations[propertyName] = _context.ChangeTracker.Generation;
return(loaded);
}
