Selecting OrmLite new object from joined table for insertion - servicestack

Question

I have 3 entities:
[CompositeIndex(nameof(Url), nameof(TargetDomainRecordId), nameof(UserAuthCustomId), Unique = true)]
public class WatchedUrlRecord
{
[AutoIncrement]
public long Id { get; set; }
public string Url { get; set; }
public string Provider { get; set; }
public string DomainKey { get; set; }
public WatchedUrlScanStatus WatchedUrlScanStatus { get; set; }
public bool NoFollow { get; set; }
public HttpStatusCode HttpStatusCode { get; set; }
public DateTime? LastScanTime { get; set; }
public WatchedUrlScanResult LastScanData { get; set; }
public string Anchors { get; set; }
public int? OutboundLinks { get; set; }
[ForeignKey(typeof(TargetDomainRecord), OnDelete = "CASCADE")]
public long TargetDomainRecordId { get; set; }
[ForeignKey(typeof(UserAuthCustom), OnDelete = "CASCADE")]
public long UserAuthCustomId { get; set; }
}
[CompositeIndex(nameof(Url), nameof(TargetDomainRecordId), nameof(UserAuthCustomId), Unique = true)]
public class WatchedUrlQueue
{
[PrimaryKey]
public long WatchedUrlRecordId { get; set; }
[Index]
public string Url { get; set; }
[Index]
public string DomainKey { get; set; }
[Index]
public long TargetDomainRecordId { get; set; }
public string TargetDomainKey { get; set; }
[Index]
public DateTime CreateDate { get; set; } = DateTime.UtcNow;
public int Tries { get; set; }
[Index]
public DateTime? DeferUntil { get; set; }
[Index]
public long UserAuthCustomId { get; set; }
[Index]
public bool FirstScan { get; set; }
}
[CompositeIndex(nameof(Url), nameof(UserAuthCustomId), Unique = true)]
public class TargetDomainRecord
{
[AutoIncrement]
public long Id { get; set; }
public string Url { get; set; }
public string DomainKey { get; set; }
public DateTime CreateDate { get; set; } = DateTime.Now;
public DateTime? DeleteDate { get; set; }
public bool IsDeleted { get; set; }
public bool Active { get; set; } = true;
public DomainType DomainType { get; set; }
[ForeignKey(typeof(UserAuthCustom), OnDelete = "CASCADE")]
public long UserAuthCustomId { get; set; }
}
I am trying to insert queue objects based on IDs of WatchedUrlRecords so I came up with this query:
var q = db.From<WatchedUrlRecord>()
.Where(x => Sql.In(x.Id, ids))
.Join<TargetDomainRecord>((w, t) => w.TargetDomainRecordId == t.Id)
.Select<WatchedUrlRecord, TargetDomainRecord>((w, t) => new WatchedUrlQueue()
{
UserAuthCustomId = w.UserAuthCustomId,
DomainKey = w.DomainKey,
CreateDate = DateTime.UtcNow,
DeferUntil = null,
FirstScan = firstScan,
TargetDomainKey = t.DomainKey,
Tries = 0,
TargetDomainRecordId = w.TargetDomainRecordId,
Url = w.Url,
WatchedUrlRecordId = w.Id
});
var inserted = db.InsertIntoSelect<WatchedUrlQueue>(q, dbCmd => dbCmd.OnConflictIgnore());
This doesn't work and gives error:
variable 'w' of type 'Project.ServiceModel.WatchedUrl.Entities.WatchedUrlRecord' referenced from scope '', but it is not defined
If I try anonymous object like new {} instead of new WatchedUrlQueue then InsertIntoSelect() throws error:
'watched_url_record"."user_auth_custom_id' is not a property of 'WatchedUrlQueue'
I have looked in documentation and can see SelectMulti() method but I don't think that is suitable as it will involve me creating a tuple list to combine into the new object. The passed list can be quite large so I just want to send the correct SQL statement to PostgreSQL which would be along lines of:
insert into watched_url_queue (watched_url_record_id, url, domain_key, target_domain_record_id, target_domain_key, create_date, tries, defer_until, user_auth_custom_id)
select wur.id watched_url_record_id,
wur.url url,
wur.domain_key,
wur.target_domain_record_id,
tdr.domain_key,
'{DateTime.UtcNow:MM/dd/yyyy H:mm:ss zzz}' create_date,
0 tries,
null defer_until,
wur.user_auth_custom_id
from watched_url_record wur
join target_domain_record tdr on wur.target_domain_record_id = tdr.id
where wur.id in (323,3213123,312312,356456)
on conflict do nothing ;
I currently have a lot of similar type queries in my app and it is causing extra work maintaining them, would be really nice to be able to have them use fluent api without reducing performance. Is this possible?

Answer 1

Custom select expression can't be a typed projection (i.e. x => new MyType { ... }), i.e. you'd need to use an anonymous type expression (i.e. new { ... }) which captures your query's Custom SELECT Projection Expression.
You'll also need to put your JOIN expressions directly after FROM (as done in SQL) which tells OrmLite it needs to fully qualify subsequent column expressions like Id which would otherwise be ambiguous.
I've resolved an issue with field resolution of custom select expressions in this commit where your query should now work as expected:
var q = db.From<WatchedUrlRecord>()
.Join<TargetDomainRecord>((w, t) => w.TargetDomainRecordId == t.Id)
.Where(x => Sql.In(x.Id, ids))
.Select<WatchedUrlRecord, TargetDomainRecord>((w, t) => new {
UserAuthCustomId = w.UserAuthCustomId,
DomainKey = w.DomainKey,
CreateDate = DateTime.UtcNow,
DeferUntil = (DateTime?) null,
FirstScan = firstScan,
TargetDomainKey = t.DomainKey,
Tries = 0,
TargetDomainRecordId = w.TargetDomainRecordId,
Url = w.Url,
WatchedUrlRecordId = w.Id
});
var inserted = db.InsertIntoSelect<WatchedUrlQueue>(q, dbCmd=>dbCmd.OnConflictIgnore());
This change is available from v5.10.5 that's now available on MyGet.