CREATE TABLE books ( book_id INT , title VARCHAR(100), author_fname VARCHAR(100), author_lname VARCHAR(100), released_year INT, stock_quantity INT, pages INT ); INSERT INTO books (book_id,title, author_fname, author_lname, released_year, stock_quantity, pages) VALUES (1,'The Namesake', 'Jhumpa', 'Lahiri', 2003, 32, 291), (1,'The Namesake', 'Jhumpa', 'Lahiri', 2003, 32, 291), (0,'The Namesake', 'Jhumpa', 'Lahiri', 2003, 32, 291), (0,'The Namesake', 'Jhumpa', 'Lahiri', 2003, 32, 291), (null,'The Namesake', 'Jhumpa', 'Lahiri', 2003, 32, 291), (null,'The Namesake', 'Jhumpa', 'Lahiri', 2003, 32, 241); CREATE TABLE books2 ( book_id INT , title VARCHAR(100), author_fname VARCHAR(100), author_lname VARCHAR(100), released_year INT, stock_quantity INT, pages INT ); INSERT INTO books2 (book_id,title, author_fname, author_lname, released_year, stock_quantity, pages) VALUES (1,'The Namesake', 'Jhumpa', 'Lahiri', 2003, 32, 291), (1,'The Namesake', 'Jhumpa', 'Lahiri', 2003, 32, 291), (1,'The Namesake', 'Jhumpa', 'Lahiri', 2003, 32, 291), (0,'The Namesake', 'Jhumpa', 'Lahiri', 2003, 32, 291), (null,'The Namesake', 'Jhumpa', 'Lahiri', 2003, 32, 291), (null,'The Namesake', 'Jhumpa', 'Lahiri', 2003, 32, 291), (null,'The Namesake', 'Jhumpa', 'Lahiri', 2003, 32, 291); -- select * from books2 -- cross join books -- on -- books.book_id = books2.book_id -- concat -- SELECT CONCAT('pi', 'ckle'); -- concat 2: columns concat -- SELECT CONCAT(author_fname,' ', author_lname) AS author_name FROM books; -- concat 3 using ws -- SELECT CONCAT_WS('-',title, author_fname, author_lname,title) FROM books; -- string issue -- SELECT SUBSTRING('Hello World', 1, 4); -- SELECT SUBSTRING('Hello World', 7); -- SELECT SUBSTRING('Hello World', -3); -- SELECT SUBSTRING(title, 1, 10) AS 'short title' FROM books; -- SELECT SUBSTR(title, 1, 10) AS 'short title' FROM books; -- Replace -- SELECT REPLACE('Hello World', '*****', '%$#@'); -- SELECT REPLACE('Hello World', 'l', '7'); -- SELECT REPLACE('Hello World', 'o', '0'); -- SELECT REPLACE('HellO World', 'o', '*'); -- SELECT -- REPLACE('cheese bread coffee milk', ' ', ' and '); -- SELECT REPLACE(title, 'e ', '3') FROM books; -- SELECT REPLACE(title, ' ', '-') FROM books; -- SELECT LEFT('omghahalol!', 3); -- SELECT RIGHT('omghahalol!', 4); SELECT Split("red:green:yellow:blue", ":") ;
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MySQL is a open-source, free and very popular relational database management system which is developed, distributed and supported by Oracle corporation.
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;