-- 1. Write a SQL statement to change the email column of employees table -- with 'not available' for all employees. -- +-------------+-------------+-------------+----------+--------------------+------------+------------+----------+----------------+------------+---------------+ -- | EMPLOYEE_ID | FIRST_NAME | LAST_NAME | EMAIL | PHONE_NUMBER | HIRE_DATE | JOB_ID | SALARY | COMMISSION_PCT | MANAGER_ID | DEPARTMENT_ID | -- +-------------+-------------+-------------+----------+--------------------+------------+------------+----------+----------------+------------+---------------+ update employees SET email = "Not available"; -- 2. Write a SQL statement to change the email and commission_pct -- column of employees table with 'not available' and 0.10 for all employees. update employees SET email = "Not available",commission_pct = 0.10; -- 3. Write a SQL statement to change the email and commission_pct column of -- employees table with 'not available' and 0.10 for those employees whose department_id is 110. UPDATE employees SET email='not available', commission_pct=0.10 WHERE department_id=110; -- 4. Write a SQL statement to change the email column of employees table -- with 'not available' for those employees whose department_id is 80 and -- gets a commission_pct is less than .20 UPDATE employees SET email = "Not avaialable" where department_id = 80 and commission_pct < .20; -- 5. Write a SQL statement to change the email column of employees table -- with 'not available' for those employees who belongs to the 'Accouning' department. -- +-------------+-------------+-------------+----------+--------------------+------------+------------+----------+----------------+------------+---------------+ -- | EMPLOYEE_ID | FIRST_NAME | LAST_NAME | EMAIL | PHONE_NUMBER | HIRE_DATE | JOB_ID | SALARY | COMMISSION_PCT | MANAGER_ID | DEPARTMENT_ID | -- +-------------+-------------+-------------+----------+--------------------+------------+------------+----------+----------------+------------+---------------+ -- |+---------------+----------------------+------------+-------------+ -- | DEPARTMENT_ID | DEPARTMENT_NAME | MANAGER_ID | LOCATION_ID | -- +---------------+----------------------+------------+-------------+ update employees email = "Not available" where(select department_id from departments where DEPARTMENT_NAME = "Accouning"); -- 6. Write a SQL statement to change salary of employee to 8000 -- whose ID is 105, if the existing salary is less than 5000. update employees salary = 8000 where DEPARTMENT_ID = 105 and salary<5000; -- 7. Write a SQL statement to change job ID of employee which ID is 118, -- to SH_CLERK if the employee belongs to department, which ID is 30 and -- the existing job ID does not start with SH. update employees set JOB_ID = "SH_CLERK" where EMPLOYEE_ID = 118 AND department_id = 30 and Not JOB_ID like "SH%"
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CREATE TABLE table_name (
column1 datatype,
column2 datatype,
....);
CREATE TABLE EMPLOYEE (
empId INTEGER PRIMARY KEY,
name TEXT NOT NULL,
dept TEXT NOT NULL
);
ALTER TABLE Table_name ADD column_name datatype;
INSERT INTO EMPLOYEE VALUES (0001, 'Dave', 'Sales');
TRUNCATE table table_name;
DROP TABLE table_name;
RENAME TABLE table_name1 to new_table_name1;
--Line1;
/* Line1,
Line2 */
INSERT INTO table_name (column1, column2, column3, ...) VALUES (value1, value2, value3, ...);
Note: Column names are optional.
INSERT INTO EMPLOYEE VALUES (0001, 'Ava', 'Sales');
SELECT column1, column2, ...
FROM table_name
[where condition];
SELECT * FROM EMPLOYEE where dept ='sales';
UPDATE table_name
SET column1 = value1, column2 = value2, ...
WHERE condition;
UPDATE EMPLOYEE SET dept = 'Sales' WHERE empId='0001';
DELETE FROM table_name where condition;
DELETE from EMPLOYEE where empId='0001';
CREATE INDEX index_name on table_name(column_name);
CREATE UNIQUE INDEX index_name on table_name(column_name);
DROP INDEX index_name ON table_name;
Creating a View:
CREATE VIEW View_name AS
Query;
SELECT * FROM View_name;
ALTER View View_name AS
Query;
DROP VIEW View_name;
CREATE TRIGGER trigger_name trigger_time trigger_event
ON tbl_name FOR EACH ROW [trigger_order] trigger_body
/* where
trigger_time: { BEFORE | AFTER }
trigger_event: { INSERT | UPDATE | DELETE }
trigger_order: { FOLLOWS | PRECEDES } */
DROP TRIGGER [IF EXISTS] trigger_name;
CREATE PROCEDURE sp_name(p1 datatype)
BEGIN
/*Stored procedure code*/
END;
CALL sp_name;
DROP PROCEDURE sp_name;
SELECT * FROM TABLE1 INNER JOIN TABLE2 where condition;
SELECT * FROM TABLE1 LEFT JOIN TABLE2 ON condition;
SELECT * FROM TABLE1 RIGHT JOIN TABLE2 ON condition;
SELECT select_list from TABLE1 CROSS JOIN TABLE2;