Trigger Verständnis

1: ALTER trigger [dbo].[uti_tm_kond_kunde] on [dbo].[tm_kond_kunde] for insert as
2: begin
3: declare
4: @maxcard  int,
5: @numrows  int,
6: @numnull  int,
7: @errno    int,
8: @errmsg   varchar(255)
9: 
10: select  @numrows = @@rowcount
11: if @numrows = 0
12: return
13: 
14: if (SELECT count(*) FROM inserted t2 WHERE t2.kond2_gueltig_von IS NULL OR t2.kond2_gueltig_bis IS NULL ) > 0
15: begin
16: 		select @errno  = 300098,
17:		@errmsg = 'ACHTUNG: Preiskonditionen ohne gültiges Datum sind ungültig!'  
18:		goto error
19: end
20: 
21: /* dies sind nur Prüfzeilen */
22: declare @adk_id int,
23: 		@pg_id int,
24: 		@counter int
25: 
26: SELECT @adk_id = adk_id, @pg_id = pg_id FROM inserted
27: print @adk_id
28: print @pg_id 
29: 
30: SELECT @counter = count(*) FROM tm_kond_kunde WHERE adk_id = @adk_id AND pg_id = @pg_id 
31: print @counter
32: /* Prüfzeilen Ende */
33: 
34: /* Hier fängt mein Problem an */
35: if ( SELECT count(*) FROM dbo.tm_kond_kunde t1, inserted t2 WHERE t1.adk_id = t2.adk_id AND t1.pg_id = t2.pg_id AND t1.kond2_gueltig_von <= GETDATE() AND t1.kond2_gueltig_bis >= GETDATE() AND t2.kond2_gueltig_von <= GETDATE() AND t2.kond2_gueltig_bis >= GETDATE()  ) > 0
36: begin
37: 		select @errno  = 300099,
38: 		@errmsg = 'ACHTUNG: Doppelter Rabattsatz darf nicht angelegt werden!'  
39: 		goto error
40: end
41: 
42: return
43: 
44: error:
45: throw  @errno, @errmsg, 1;
46: rollback  transaction
47: end