Dear all,
I have a table by name image_master whose structure is as below:
IMAGE_NAME NOT NULL
VARCHAR2(60)
TYPE NOT NULL
CHAR(1)
START_DT NOT NULL
VARCHAR2(8)
EXPIRY_DT
VARCHAR2(8)
IMAGE_DESC
VARCHAR2(600)
CREATE_DT
VARCHAR2(8)
MODIFY_DT
VARCHAR2(8)
The dates are entered in the form 'yyyymmdd'. All the dates have been
assigned the datatype as varchar2(8) instead of date for a specific reason.
I would like to create a before insert trigger on the table so that the
user cannot insert a record if the start_dt and expiry_dt overlap the
existing start_dt and expiry_dt in the existing records. For example, if
there is a record whose start_dt is 20001126 and end_dt is 20001128 then
the user is not allowed to have start_dt and end_dt between 26th and 28th
November, 2000 (both dates inclusive). His start_dt and end_dt can be any
dates apart from 26th, 27th and 28th November. How do I implement this
using SQL or PL/SQL? Is there any other way out apart from creating a
before insert trigger? I hope I am clear. Any help in this regard will
be highly appreciated.
Received on Tue Nov 28 2000 - 01:20:04 CST
