First, INSERT statements are 1 to 1 with table rows... (unless you use a insert/select).
Second, if you want to probe that.. it is better to create an UNIQUE index.. isn't it? Ok, if that's not enough for you... you can create a trigger that perform a SELECT COUNT(*) with the criteria and if it's > 0, you rise an exception (sorry, I don't have access to a databae now to check the code). Juan C. Olivares www.juancri.com ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match