PostgreSQL Insert Record: Insert one row into a table to ensure that no duplicate values will be entered in the key column
7. Write a SQL statement to insert one row in the jobs table to ensure that no duplicate values will be entered into the job_id column.
Here is the code to create a sample table jobs:
CREATE TABLE jobs ( JOB_ID integer NOT NULL UNIQUE , JOB_TITLE varchar(35) NOT NULL, MIN_SALARY decimal(6,0) );
Now insert a row into the table jobs :
INSERT INTO jobs VALUES(1001,'OFFICER',8000);
Here is the command to see the list of inserting rows :
postgres=# SELECT * FROM jobs; job_id | job_title | min_salary --------+-----------+------------ 1001 | OFFICER | 8000 (1 row)
Now, try to insert the duplicate value in the key column and see what happen :
postgres=# INSERT INTO jobs VALUES(1001,'OFFICER',8000); ERROR: duplicate key value violates unique constraint "jobs_job_id_key" DETAIL: Key (job_id)=(1001) already exists.
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