SQLite Exercise: Display the jobs/designations available in the employees table
Write a query to display the jobs/designations available in the employees table.
Sample table: employees
+-------------+-------------+-------------+----------+--------------------+------------+------------+----------+----------------+------------+---------------+ | EMPLOYEE_ID | FIRST_NAME | LAST_NAME | EMAIL | PHONE_NUMBER | HIRE_DATE | JOB_ID | SALARY | COMMISSION_PCT | MANAGER_ID | DEPARTMENT_ID | +-------------+-------------+-------------+----------+--------------------+------------+------------+----------+----------------+------------+---------------+ | 100 | Steven | King | SKING | 515.123.4567 | 1987-06-17 | AD_PRES | 24000.00 | 0.00 | 0 | 90 | | 101 | Neena | Kochhar | NKOCHHAR | 515.123.4568 | 1987-06-18 | AD_VP | 17000.00 | 0.00 | 100 | 90 | | 102 | Lex | De Haan | LDEHAAN | 515.123.4569 | 1987-06-19 | AD_VP | 17000.00 | 0.00 | 100 | 90 | | 103 | Alexander | Hunold | AHUNOLD | 590.423.4567 | 1987-06-20 | IT_PROG | 9000.00 | 0.00 | 102 | 60 | | 104 | Bruce | Ernst | BERNST | 590.423.4568 | 1987-06-21 | IT_PROG | 6000.00 | 0.00 | 103 | 60 | | 105 | David | Austin | DAUSTIN | 590.423.4569 | 1987-06-22 | IT_PROG | 4800.00 | 0.00 | 103 | 60 | | 106 | Valli | Pataballa | VPATABAL | 590.423.4560 | 1987-06-23 | IT_PROG | 4800.00 | 0.00 | 103 | 60 | | 107 | Diana | Lorentz | DLORENTZ | 590.423.5567 | 1987-06-24 | IT_PROG | 4200.00 | 0.00 | 103 | 60 | | 108 | Nancy | Greenberg | NGREENBE | 515.124.4569 | 1987-06-25 | FI_MGR | 12000.00 | 0.00 | 101 | 100 | | 109 | Daniel | Faviet | DFAVIET | 515.124.4169 | 1987-06-26 | FI_ACCOUNT | 9000.00 | 0.00 | 108 | 100 | ........... | 206 | William | Gietz | WGIETZ | 515.123.8181 | 1987-10-01 | AC_ACCOUNT | 8300.00 | 0.00 | 205 | 110 | +-------------+-------------+-------------+----------+--------------------+------------+------------+----------+----------------+------------+---------------+
SQLite Code :
-- Selecting distinct values from the "job_id" column
SELECT DISTINCT job_id
-- Specifying the table from which to retrieve the data, in this case, "employees"
FROM employees;
Output:
job_id AD_PRES AD_VP IT_PROG FI_MGR FI_ACCOUNT PU_MAN PU_CLERK ST_MAN ST_CLERK SA_MAN SA_REP SH_CLERK AD_ASST MK_MAN MK_REP HR_REP PR_REP AC_MGR AC_ACCOUNT
Explanation:
The above SQLite query retrieves a list of unique job IDs from the "employees" table. The DISTINCT keyword ensures that each job ID is represented only once in the result set.
Here's a brief explanation of each part of SQLite code:
- SELECT clause:
- It selects distinct values from the "job_id" column in the "employees" table.
- FROM clause:
- Specifies the table from which to retrieve the data, in this case, the "employees" table.
- DISTINCT keyword:
- Ensure that only unique values of "job_id" are returned in the result set. If there are duplicate job IDs in the "employees" table, only one instance of each unique job ID will be included in the result.
Relational Algebra Expression:
Relational Algebra Tree:
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Practice SQLite Online
Model Database
Structure of 'hr' database :
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