SQLite Exercise: Display the last names of employees whose names have exactly 6 characters
Write a query to display the last names of employees whose names have exactly 6 characters.
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 the "last_name" column
SELECT last_name
-- Specifying the table from which to retrieve the data, in this case, "employees"
FROM employees
-- Filtering the results to include only rows where the "last_name" has exactly six characters
WHERE last_name LIKE '______';
Output:
last_name ---------- Hunold Austin Faviet Tobias Himuro ... Cabrio McCain Feeney Whalen Mavris
Explanation:
The above SQLite query retrieves the "last_name" values from the "employees" table but only includes rows where "last_name" has exactly six characters. The LIKE operator is employed to perform this pattern matching condition.
Here's a brief explanation of each part of SQLite code:
- SELECT clause:
- It selects the "last_name" column from the "employees" table.
- FROM clause:
- Specifies the table from which to retrieve the data, in this case, the "employees" table.
- WHERE clause:
- Filters the results to include only rows where the "last_name" has exactly six characters.
- The LIKE operator with '______' is used for pattern matching, where each underscore represents a single character.
Relational Algebra Expression:
Relational Algebra Tree:
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PREV : Write a query to display the last name, job, and salary for all employees whose job is that of a Programmer or a Shipping Clerk, and whose salary is not equal to $4,500, $10,000, or $15,000.
NEXT : Write a query to display the last names of employees having 'e' as the third character.
Practice SQLite Online
Model Database
Structure of 'hr' database :
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