internal override SqlStatement VisitDelete(SqlDelete sd)
{
SqlScope save = this.CurrentScope;
this.CurrentScope = new SqlScope(sd, this.CurrentScope.ContainingScope);
base.VisitDelete(sd);
this.CurrentScope = save;
return sd;
}
internal virtual SqlStatement VisitDelete(SqlDelete delete) {
delete.Select = this.VisitSequence(delete.Select);
return delete;
}
private SqlStatement VisitDelete(Expression item, LambdaExpression check)
{
if(item == null)
{
throw Error.ArgumentNull("item");
}
bool saveAllowDeferred = _allowDeferred;
_allowDeferred = false;
try
{
MetaTable metaTable = _services.Model.GetTable(item.Type);
Expression source = _services.Context.GetTable(metaTable.RowType.Type).Expression;
Type rowType = metaTable.RowType.Type;
// construct identity predicate based on supplied item
ParameterExpression p = Expression.Parameter(rowType, "p");
LambdaExpression idPredicate = Expression.Lambda(Expression.Equal(p, item), p);
// combine predicate and check expression into single find predicate
LambdaExpression findPredicate = idPredicate;
if(check != null)
{
findPredicate = Expression.Lambda(Expression.And(Expression.Invoke(findPredicate, p), Expression.Invoke(check, p)), p);
}
Expression seq = Expression.Call(typeof(Enumerable), "Where", new Type[] { rowType }, source, findPredicate);
SqlSelect ss = new RetypeCheckClause().VisitSelect(this.VisitSequence(seq));
_allowDeferred = saveAllowDeferred;
SqlDelete sd = new SqlDelete(ss, source);
return sd;
}
finally
{
_allowDeferred = saveAllowDeferred;
}
}
internal override SqlStatement VisitDelete(SqlDelete sd)
{
_commandStringBuilder.Append("DELETE FROM ");
_suppressedAliases.Add(sd.Select.From);
this.Visit(sd.Select.From);
if(sd.Select.Where != null)
{
_commandStringBuilder.Append(" WHERE ");
this.Visit(sd.Select.Where);
}
_suppressedAliases.Remove(sd.Select.From);
return sd;
}
internal override SqlStatement VisitDelete(SqlDelete sd)
{
return new SqlDelete((SqlSelect)this.Visit(sd.Select), sd.SourceExpression);
}
internal override SqlStatement VisitDelete(SqlDelete sd)
{
bool saveTop = this.topLevel;
this.topLevel = false;
base.VisitDelete(sd);
this.topLevel = saveTop;
return sd;
}
