public override DbExpression Visit(DbScanExpression expression)
{
var column = SoftDeleteAttribute.GetSoftDeleteColumnName(expression.Target.ElementType);
if (column != null)
{
// Just because the entity has the soft delete annotation doesn't mean that
// this particular table has the column. This occurs in situation like TPT
// inheritance mapping and entity splitting where one type maps to multiple
// tables.
// We only apply the filter if the column is actually present in this table.
// If not, then the query is going to be joining to the table that does have
// the column anyway, so the filter will still be applied.
var table = (EntityType)expression.Target.ElementType;
if (table.Properties.Any(p => p.Name == column))
{
var binding = DbExpressionBuilder.Bind(expression);
return(DbExpressionBuilder.Filter(
binding,
DbExpressionBuilder.NotEqual(
DbExpressionBuilder.Property(
DbExpressionBuilder.Variable(binding.VariableType, binding.VariableName),
column),
DbExpression.FromBoolean(true))));
}
}
return(base.Visit(expression));
}
public void TreeCreated(DbCommandTreeInterceptionContext interceptionContext)
{
if (interceptionContext.OriginalResult.DataSpace == DataSpace.SSpace)
{
var queryCommand = interceptionContext.Result as DbQueryCommandTree;
if (queryCommand != null)
{
var newQuery = queryCommand.Query.Accept(new SoftDeleteQueryVisitor());
interceptionContext.Result = new DbQueryCommandTree(
queryCommand.MetadataWorkspace,
queryCommand.DataSpace,
newQuery);
}
var deleteCommand = interceptionContext.OriginalResult as DbDeleteCommandTree;
if (deleteCommand != null)
{
var column = SoftDeleteAttribute.GetSoftDeleteColumnName(deleteCommand.Target.VariableType.EdmType);
if (column != null)
{
// Just because the entity has the soft delete annotation doesn't mean that
// this particular table has the column. This occurs in situation like TPT
// inheritance mapping and entity splitting where one type maps to multiple
// tables.
// If the table doesn't have the column we just want to leave the row unchanged
// since it will be joined to the table that does have the column during query.
// We can't no-op, so we just generate an UPDATE command that doesn't set anything.
var setClauses = new List <DbModificationClause>();
var table = (EntityType)deleteCommand.Target.VariableType.EdmType;
if (table.Properties.Any(p => p.Name == column))
{
setClauses.Add(DbExpressionBuilder.SetClause(
DbExpressionBuilder.Property(
DbExpressionBuilder.Variable(deleteCommand.Target.VariableType, deleteCommand.Target.VariableName),
column),
DbExpression.FromBoolean(true)));
}
var update = new DbUpdateCommandTree(
deleteCommand.MetadataWorkspace,
deleteCommand.DataSpace,
deleteCommand.Target,
deleteCommand.Predicate,
setClauses.AsReadOnly(),
null);
interceptionContext.Result = update;
}
}
}
}
