| Subject | Alternative for UNIQUE constraint |
|---|---|
| Author | magic1278 |
| Post date | 2009-03-28T01:23:45Z |
Is there an alternative for the UNIQUE constraint? I tried to create a table using the following, but I got an error message saying an index is too long or something:
CREATE TABLE tblFiles (
ID INTEGER
NOT NULL
PRIMARY KEY
CHECK (VALUE >= 0),
Filename CHAR (260) CHARACTER SET UTF8
NOT NULL,
Volume INTEGER
NOT NULL
DEFAULT -1
CHECK (VALUE >= -1)
REFERENCES tblVolumes (ID)
ON UPDATE SET DEFAULT
ON DELETE SET DEFAULT,
UNIQUE (Volume, Filename)
);
I just want to enforce all Volume/Filename pairs to be unique. As this is for a program which I'm making to track what files I stuff on each DVD I make, Filename may not necessarily be unique by itself, because I might have a "\blah.ext" on multiple disks.
CREATE TABLE tblFiles (
ID INTEGER
NOT NULL
PRIMARY KEY
CHECK (VALUE >= 0),
Filename CHAR (260) CHARACTER SET UTF8
NOT NULL,
Volume INTEGER
NOT NULL
DEFAULT -1
CHECK (VALUE >= -1)
REFERENCES tblVolumes (ID)
ON UPDATE SET DEFAULT
ON DELETE SET DEFAULT,
UNIQUE (Volume, Filename)
);
I just want to enforce all Volume/Filename pairs to be unique. As this is for a program which I'm making to track what files I stuff on each DVD I make, Filename may not necessarily be unique by itself, because I might have a "\blah.ext" on multiple disks.