How to guarantee uniqueness of a record using a complex key?
There is a simple table, with 3-rd foreign keys. How to make it impossible to re-record with the same values for these three keys? Create a complex key based on them?
And how to do it in the Workbench environment, just specify additionally each foreign key as a primary key?
mysql sql
asked Nov 18 '18 at 1:38
OPV
1,49921330
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There is a simple table, with 3-rd foreign keys. How to make it impossible to re-record with the same values for these three keys? Create a complex key based on them?
And how to do it in the Workbench environment, just specify additionally each foreign key as a primary key?
mysql sql
asked Nov 18 '18 at 1:38
OPV
1,49921330
add a comment |
There is a simple table, with 3-rd foreign keys. How to make it impossible to re-record with the same values for these three keys? Create a complex key based on them?
And how to do it in the Workbench environment, just specify additionally each foreign key as a primary key?
mysql sql
asked Nov 18 '18 at 1:38
OPV
1,49921330
There is a simple table, with 3-rd foreign keys. How to make it impossible to re-record with the same values for these three keys? Create a complex key based on them?
And how to do it in the Workbench environment, just specify additionally each foreign key as a primary key?
mysql sql
mysql sql
asked Nov 18 '18 at 1:38
OPV
1,49921330
asked Nov 18 '18 at 1:38
OPV
1,49921330
asked Nov 18 '18 at 1:38
OPV
1,49921330
asked Nov 18 '18 at 1:38
OPV
1,49921330
asked Nov 18 '18 at 1:38
OPV
1,49921330
1,49921330
add a comment |
add a comment |
1 Answer
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If i get your question, you are looking to enforce uniqueness in the columns (user_id,position_id,organization_id).
Assuming that at least one of the columns is (not null). If you were to create a unique index on the three columns it should work.
CREATE UNIQUE INDEX index_name
ON Employers(user_id,position_id,organization_id);
answered Nov 18 '18 at 2:31
George Joseph
1,33249
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
If i get your question, you are looking to enforce uniqueness in the columns (user_id,position_id,organization_id).
Assuming that at least one of the columns is (not null). If you were to create a unique index on the three columns it should work.
CREATE UNIQUE INDEX index_name
ON Employers(user_id,position_id,organization_id);
answered Nov 18 '18 at 2:31
George Joseph
1,33249
add a comment |
If i get your question, you are looking to enforce uniqueness in the columns (user_id,position_id,organization_id).
Assuming that at least one of the columns is (not null). If you were to create a unique index on the three columns it should work.
CREATE UNIQUE INDEX index_name
ON Employers(user_id,position_id,organization_id);
answered Nov 18 '18 at 2:31
George Joseph
1,33249
add a comment |
If i get your question, you are looking to enforce uniqueness in the columns (user_id,position_id,organization_id).
Assuming that at least one of the columns is (not null). If you were to create a unique index on the three columns it should work.
CREATE UNIQUE INDEX index_name
ON Employers(user_id,position_id,organization_id);
answered Nov 18 '18 at 2:31
George Joseph
1,33249
If i get your question, you are looking to enforce uniqueness in the columns (user_id,position_id,organization_id).
Assuming that at least one of the columns is (not null). If you were to create a unique index on the three columns it should work.
CREATE UNIQUE INDEX index_name
ON Employers(user_id,position_id,organization_id);
answered Nov 18 '18 at 2:31
George Joseph
1,33249
answered Nov 18 '18 at 2:31
George Joseph
1,33249
answered Nov 18 '18 at 2:31
George Joseph
1,33249
answered Nov 18 '18 at 2:31
George Joseph
1,33249
1,33249
add a comment |
add a comment |
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