sql statements & joins
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The document introduces SQL statements and joins. It discusses the main SQL statement types - DDL, DML, DCL, DQL - and provides examples of commands like CREATE, DROP, ALTER, INSERT, UPDATE, DELETE, GRANT, REVOKE, SELECT. It also explains different types of joins in SQL - INNER JOIN, LEFT JOIN, RIGHT JOIN, FULL JOIN - and provides the syntax for each.
![DML Statements
•Update – modify the existing records in a table
•Syntax
UPDATE TABLE table_name SET
column_name1=value1,….column_namen=valuen WHERE
[condition];
•Example:
UPDATE TABLE tbl_studetns SET student_place=‘Calicut’ WHERE
student_id=1;](https://image.slidesharecdn.com/sql-150807064357-lva1-app6892/85/sql-statements-joins-10-320.jpg)
![DML Statements
•Delete – delete the existing records from a table
•Syntax
DELETE FROM table_name WHERE [condition];
•Example:
DELETE FROM tbl_students WHERE student_id=1;](https://image.slidesharecdn.com/sql-150807064357-lva1-app6892/85/sql-statements-joins-11-320.jpg)
![DCL Statements
•Grant – gives a privilege to user
•Syntax -
GRANT privilege_name ON object_name
TO {user_name |PUBLIC |role_name} [WITH GRANT OPTION];
•Revoke- takes back proivilages granted from user
•syntax -
REVOKE privilege_name ON object_name FROM {user_name
|PUBLIC |role_name}](https://image.slidesharecdn.com/sql-150807064357-lva1-app6892/85/sql-statements-joins-12-320.jpg)
![DQL – SELECT Statement
•SELECT column_name1, column_name2,…column_nameN
FROM table_name WHERE [condition];
•Example:
•SELECT * FROM tbl_students;
•SELECT student_id,student_name FROM tbl_students;
•SELECT student_name FROM tbl_students WHERE student_id=1;](https://image.slidesharecdn.com/sql-150807064357-lva1-app6892/85/sql-statements-joins-14-320.jpg)
sql statements & joins
- 1. WELCOME
- 2. SQL Statements & Joins
- 3. Introduction •SQL – Structured Query Language •SQL lets you access and manipulate database
- 4. SQL Statements •DDL - Data Definition Language – Create, alter, drop,truncate… •DML - Data Manipulation Language – Insert, update, delete… •DCL – Data Control Language – grant, revoke •DQL –Data Query Language –select
- 5. DDL Statements •Create - create database, table, view of table , or other object in database •Syntax - CREATE DATABASE database_name; CREATE TABLE table_name(column_name1 datatype, column_name2 datatype,…..) PRIMARY KEY(column_name(s));
- 6. DDL Statements •Drop - drop an existing database in SQL schema, drop a table definition and all data… •Syntax DROP DATABASE database_name; DROP TABLE table_name; •Example: •DROP TABLE tbl_students;
- 7. DDL Statements •Alter - modifies an existing database object like table… •Syntax - •ALTER TABLE table_name –ADD column_name datatype –DROP COLUMN column_name –MODIFY COLUMN column_name datatype
- 8. DDL Statements •Truncate – delete complete data from an existing table •Syntax TRUNCATE TABLE table_name;
- 9. DML Statements •Insert – creates a record •Syntax - INSERT INTO table_name(column_name1,column_name2….) values(value1,value2….); INSERT INTO table_name values(value1,value2….);
- 10. DML Statements •Update – modify the existing records in a table •Syntax UPDATE TABLE table_name SET column_name1=value1,….column_namen=valuen WHERE [condition]; •Example: UPDATE TABLE tbl_studetns SET student_place=‘Calicut’ WHERE student_id=1;
- 11. DML Statements •Delete – delete the existing records from a table •Syntax DELETE FROM table_name WHERE [condition]; •Example: DELETE FROM tbl_students WHERE student_id=1;
- 12. DCL Statements •Grant – gives a privilege to user •Syntax - GRANT privilege_name ON object_name TO {user_name |PUBLIC |role_name} [WITH GRANT OPTION]; •Revoke- takes back proivilages granted from user •syntax - REVOKE privilege_name ON object_name FROM {user_name |PUBLIC |role_name}
- 13. DQL – SELECT Statement •Fetch the data from a database table which returns data in the form of result table •Syntax - -select columns SELECT column_name1, column_name2,…column_nameN FROM table_name ; -select all data from table SELECT * FROM table_name;
- 14. DQL – SELECT Statement •SELECT column_name1, column_name2,…column_nameN FROM table_name WHERE [condition]; •Example: •SELECT * FROM tbl_students; •SELECT student_id,student_name FROM tbl_students; •SELECT student_name FROM tbl_students WHERE student_id=1;
- 15. SQL Joins •Combines two or more table , based on a common field between them •Different SQL Joins –INNER JOIN –LEFT JOIN –RIGHT JOIN –FULL JOIN
- 16. SQL Joins •INNER JOIN - Returns all rows when there is at least one match in BOTH tables •Syntax - SELECT column-name(s) FROM table_name1 INNER JOIN table_name2 on table1.column_name=table2.column_name;
- 17. SQL Joins •LEFT JOIN - Return all rows from the left table, and the matched rows from the right table •Syntax - SELECT column-name(s) FROM table_name1 LEFT JOIN table_name2 on table1.column_name=table2.column_name; SELECT column_name(s) FROM table_name1 LEFT OUTER JOIN table_name2 ON table1.column_name=table2.column_name;
- 18. SQL Joins •RIGHT JOIN - Return all rows from the right table, and the matched rows from the left table •Syntax - SELECT column-name(s) FROM table_name1 RIGHT JOIN table_name2 on table1.column_name=table2.column_name; SELECT column_name(s) FROM table_name1 RIGHT OUTER JOIN table_name2 ON table1.column_name=table2.column_name;
- 19. SQL Joins •FULL JOIN - Return all rows when there is a match in ONE of the tables •Syntax - SELECT column-name(s) FROM table_name1 FULL OUTER JOIN table_name2 on table1.column_name=table2.column_name;