SQL-Structured Query Language BY : SHIVENDER KUMAR BHARDWAJ PGT-TAFS

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1 SQL-Structured Query Language BY : SHIVENDER KUMAR BHARDWAJ PGT-TAFS

2 Overview Introduction DDL Commands DML Commands SQL Statements, Operators, Clauses Aggregate Functions 2

3 ( SQL ) Structured Query Language The ANSI standard language for the definition and manipulation of relational database. Includes data definition language (DDL), statements that specify and modify database schemas. Includes a data manipulation language (DML), statements that manipulate database content. 3

4 Some Facts on SQL SQL data is case-sensitive, SQL commands are not. First Version was developed at IBM by Donald D. Chamberlin and Raymond F. Boyce. [SQL] Developed using Dr. E.F. Codd's paper, A Relational Model of Data for Large Shared Data Banks. SQL query includes references to tuples variables and the attributes of those variables 4

5 DDL - Primitive Types numeric INTEGER (or INT), SMALLINT are subsets of the integers (machine dependent) REAL, DOUBLE PRECISION are floating-point and double-precision floating-point (machine dependent) FLOAT(N) is floating-point with at least N digits DECIMAL(P,D) (or DEC(P,D), or NUMERIC(P,D)), with P digits of which D are to the right of the decimal point 5

6 DDL - Primitive Types (cont.) character-string CHAR(N) (or CHARACTER(N)) is a fixed-length character string VARCHAR(N) (or CHAR VARYING(N), or CHARACTER VARYING(N)) is a variable-length character string with at most N characters DATE is a date: YYYY-MM-DD 6

7 SQL: DDL Commands CREATE TABLE: used to create a table. ALTER TABLE: modifies a table after it was created. DROP TABLE: removes a table from a database. 7

8 SQL: CREATE TABLE Statement Things to consider before you create your table are: The type of data the table name what column(s) will make up the primary key the names of the columns CREATE TABLE statement syntax: CREATE TABLE <table name> ( field1 datatype ( NOT NULL ), field2 datatype ( NOT NULL ) ); 8

9 CREATE TABLE statement syntax: CREATE TABLE <table name> ( field1 datatype ( NOT NULL ), field2 datatype ( NOT NULL ) ); Example: CREATE TABLE FoodCart ( date varchar(10), food varchar(20), profit float ); FoodCart date food profit 9

10 SQL: ALTER TABLE Statement To add, modify or drop columns on existing tables. ALTER TABLE <table name> ADD attr datatype; ALTER TABLE <table name> DROP COLUMN attr; ALTER TABLE <table name> MODIFY attr datatype; 10

11 Example: ALTER TABLE FoodCart ( ADD sold int ); FoodCart date food date food profit profit sold ALTER TABLE FoodCart ( MODIFY sold float(5) ); date food sold ALTER TABLE FoodCart( DROP COLUMN profit ); date food sold DROP TABLE FoodCart; 11

12 SQL: DML Commands INSERT: adds new rows to a table. UPDATE: modifies one or more attributes. DELETE: deletes one or more rows from a table. 12

13 SQL: INSERT Statement To insert a row into a table, it is necessary to have a value for each attribute, and order matters. INSERT statement syntax: INSERT into <table name> VALUES ('value1', 'value2', NULL); Example: INSERT into FoodCart VALUES ( 02/26/08', pizza', 70 ); date 02/25/08 02/26/08 food pizza hotdog sold date 02/25/08 02/26/08 02/26/08 food pizza hotdog pizza sold

14 SQL: UPDATE Statement To update the content of the table: UPDATE statement syntax: UPDATE <table name> SET <attr> = <value> WHERE <selection condition>; Example: UPDATE FoodCart SET sold = 349 WHERE date = 02/25/08 AND food = pizza ; date 02/25/08 02/26/08 02/26/08 food pizza hotdog pizza sold date 02/25/08 02/26/08 02/26/08 food pizza hotdog pizza sold

15 Updating Records cont d update phone_book set area_code = 623 where prefix = 979; This changes the area code all numbersbeginning with 979 to

16 Updating Records cont d update phone_book set last_name = 'Smith', prefix=555, sufix=9292 where last_name = 'Jones'; This changes everyone whose last name is Jones to Smith and their number to

17 SQL: DELETE Statement To delete rows from the table: DELETE statement syntax: DELETE FROM <table name> WHERE <condition>; Example: DELETE FROM FoodCart WHERE food = hotdog ; date food sold date food sold 02/25/08 pizza /25/08 pizza /26/08 hotdog /26/08 pizza 70 02/26/08 pizza 70 Note: If the WHERE clause is omitted all rows of data are deleted from the table. 17

18 Deleting Records Examples ex) delete from employees; deletes all records from that table ex) delete from employee where lastname='may'; deletes all records for people whose last name is May ex) delete from employee where firstname='mike' or firstname='eric'; deletes all records for anyone whose first name is Mike or Eric 18

19 SQL Statements, Operations, Clauses SQL Statements: Select SQL Operations: Join Like SQL Clauses: Order By Group By Having 19

20 SQL: SELECT Statement A basic SELECT statement includes 3 clauses SELECT <attribute name> FROM <tables> WHERE <condition> SELECT Specifies the attributes that are part of the resulting relation FROM Specifies the tables that serve as the input to the statement WHERE Specifies the selection condition, including the join condition. Note: that you don't need to use WHERE 20

21 (. cont ) SQL: SELECT Statement Using a * in a select statement indicates that every attribute of the input table is to be selected. Example: SELECT * FROM WHERE ; To get unique rows, type the keyword DISTINCT after SELECT. Example: SELECT DISTINCT * FROM WHERE ; 21

22 Relational Operators Logical Operator AND OR NOT 22

23 Example: Person Name Harry Sally George Helena Peter Age Weight ) SELECT weight FROM person WHERE age > 30; Weight ) SELECT * FROM person WHERE age > 30; Name Harry Helena Peter Age Weight ) SELECT distinct weight FROM person WHERE age > 30; Weight

24 SQL: Like operation Pattern matching selection ( string (arbitrary % SELECT * FROM emp WHERE ID like %01 ; finds ID that ends with 01, e.g. 1001, 2001, etc ( character (a single _ SELECT * FROM emp WHERE ID like _01_ ; finds ID that has the second and third character as 01, e.g. 1010, 1011, 1012, 1013, etc 24

25 IN Operator IN is used to test whether or not a value (stated before the keyword IN) is "in" the list of values provided after the keyword IN. SELECT employeeid, lastname, salary FROM employee_info WHERE lastname IN ('Hernandez', 'Jones', 'Roberts', 'Ruiz'); SELECT employeeid, lastname, salary FROM employee_info WHERE lastname = 'Hernandez' OR lastname = 'Jones' OR lastname = 'Roberts OR lastname = 'Ruiz'; You can also use NOT IN to exclude the rows in your list. 25

26 BETWEEN Operator The BETWEEN conditional operator is used to test to see whether or not a value (stated before the keyword BETWEEN) is "between" the two values stated after the keyword BETWEEN. SELECT employeeid, age, lastname, salary FROM employee_info WHERE age BETWEEN 30 AND 40; This statement will select the employeeid, age, lastname, and salary from the employee_info table where the age is between 30 and 40 (including 30 and 40). SELECT employeeid, age, lastname, salary FROM employee_info WHERE age >= 30 AND age <= 40; 26

27 SQL: The ORDER BY Clause Ordered result selection ( order desc (descending SELECT * FROM emp order by state desc puts state in descending order, e.g. TN, MA, CA ( order asc (ascending SELECT * FROM emp order by id asc puts ID in ascending order, e.g. 1001, 1002,

28 SQL: The GROUP BY Clause The function to divide the tuples into groups and returns an aggregate for each group. Usually, it is an aggregate function s companion SELECT food, sum(sold) as totalsold FROM FoodCart group by food; date food sold food totalsold 02/25/08 pizza 349 hotdog /26/08 hotdog 500 pizza /26/08 pizza 70 28

29 SQL: Aggregate Functions Are used to provide summarization information for SQL statements, which return a single value. ( COUNT(attr ( SUM(attr ( MAX(attr ( MIN(attr ( AVG(attr Note: when using aggregate functions, NULL values are not considered, except in COUNT(*). 29

30 (. cont ) SQL: Aggregate Functions FoodCart date 02/25/08 02/26/08 02/26/08 food pizza hotdog pizza sold COUNT(attr) -> return # of rows that are not null SELECT COUNT(distinct food) from FoodCart; -> 2 SUM(attr) -> return the sum of values in the attr SELECT SUM(sold) from FoodCart; -> 919 MAX(attr) -> return the highest value from the attr SELECT MAX(sold) from FoodCart; ->

31 (. cont ) SQL: Aggregate Functions FoodCart date 02/25/08 02/26/08 02/26/08 food pizza hotdog pizza sold MIN(attr) -> return the lowest value from the attr Ex: SELECT MIN(sold) from FoodCart; -> 70 AVG(attr) -> return the average value from the attr Ex: SELECT AVG(sold) from FoodCart; -> Note: value is rounded to the precision of the datatype 31 70

32 SQL: The HAVING Clause The substitute of WHERE for aggregate functions Usually, it is an aggregate function s companion SELECT food, sum(sold) as totalsold FROM FoodCart group by food having sum(sold) > 450; date food sold food totalsold 02/25/08 pizza 349 hotdog /26/08 hotdog /26/08 pizza 70 32

33 items_ordered customerid order_date item quantity price customers customerid firstname lastname city state 1) How many people are in each unique state in the customers table that have more than one person in the state? Select the state and display the number of how many people are in each if it's greater than 1. 2) From the items_ordered table, select the item, maximum price, and minimum price for each specific item in the table. Only display the results if the maximum price for one of the items is greater than ) How many orders did each customer make? Use the items_ordered table. Select the customerid, number of orders they made, and the sum of their orders if they purchased more than 1 item. 33

34 Exercise #1 SELECT state, count(state) FROM customers GROUP BY state HAVING count(state) > 1; Exercise #2 SELECT item, max(price), min(price) FROM items_ordered GROUP BY item HAVING max(price) > ; Exercise #3 SELECT customerid, count(customerid), sum(price) FROM items_ordered GROUP BY customerid HAVING count(customerid) > 1; 34

35 SQL: Join operation A join can be specified in the FROM clause which list the two input relations and the WHERE clause which lists the join condition. Example: Emp ID State CA MA TN Dept ID Division IT Sales Biotech 35

36 (. cont ) SQL: Join operation SELECT * FROM emp, dept WHERE emp.id = dept.id; Emp.ID Emp.State Dept.ID Dept.Division 1001 MA 1001 IT 1002 TN 1002 Sales 36

37 SS T S T S union T SELECT FLT# FROM FLT-WEEKDAY WHERE WEEKDAY = TU UNION SELECT FLT# FROM FLT-INSTANCE WHERE #AVAIL-SEATS > 100; UNION ALL preserves duplicates 37

38 S T S intersect T SELECT FLT# FROM FLT-WEEKDAY WHERE WEEKDAY = TU INTERSECT SELECT FLT# FROM FLT-INSTANCE WHERE #AVAIL-SEATS > 100; INTERSECT ALL preserves duplicates 38

39 Working with more than one table Syntax: SELECT col1, col2, col3... FROM table_name1, table_name2 WHERE table_name1.col2 = table_name2.col1; 39

40 Table - product product_id product_na me supplier_n ame unit_pric e Table - order_items order_id product_id total_u customer nits 100 Camera Nikon Television Onida Refrigerator Videocon Ipod Apple Mobile Nokia Infosys Satyam Wipro TCS SELECT order_id, product_name, unit_price, supplier_name, total_units FROM product, order_items WHERE order_items.product_id = product.product_id; 40

41 ggames Gcode Gamename Number_of_ participants Prizemoney Scheduledate 101 Carom Board Jan Badminton Dec Table Tennis Feb Chess Jan Lawn Tennis Mar 2004 i) To display the name of all games with their gcode. ii) To display details of those games which are having prizemoney more than 7000 iii) To display the contents of the games table in ascending order of scheduledate. iv) To display sum of prizemoney for each of the number of participation grouping. v) To display the maximum and minimum schedule date from games table 41

42 i) To display the name of all games with their gcode. SELECT GCODE, GAMENAME FROM GAMES; i) To display details of those games which are having prizemoney more than 7000 SELECT * FROM GAMES WHERE PRIZEMONEY >7000; i) To display the contents of the games table in ascending order of scheduledate. SELECT * FROM GAMES ORDER BY SCHEDULEDATE; i) To display sum of prizemoney for each of the number of participation grouping. SELECT NUM, SUM(PRIZEMONY) FROM GAMES GROUP BY NUM_OF_PARTICIPANTS; i) To display the maximum and minimum schedule date from games table SELECT MAX(SCHEDULEDATE), MIN(SCHEDULEDATE) FROM GAMES; 42

43 WORKER ID FIRSTNAME LASTNAME CITY SALARY DESIGNATION 102 Sam Tones Paris Manager 105 Sarah Ackerman New York Director 144 Manila Sengupta New delhi Manager 210 George Smith Howard Manager 255 Mary Jones Losantiville Clerk 300 Robert Samuel Washington Clerk 335 Henry William Boston Clerk 403 Ronny Lee New York Salesman 451 Pat Thompson Paris Salesman (i) (ii) (iii) (iv) (v) Display details of all employees living in New York. Display contents of worker table in descending order of LASTNAME. To display the FIRSTNAME, LASTNAME and salary of all Clerks. To display the minimum and maximum SALARY To display the number of workers in each city. 43

44 (i) Display details of all employees living in New York. SELECT * FROM WORKER WHERE CITY = NEW YORK ; (i) Display contents of worker table in descending order of LASTNAME. SELECT * FROM WORKER ORDER BY LASTNAME DESC; (i) To display the FIRSTNAME, LASTNAME and salary of all Clerks. SELECT FIRSTNAME, LASTNAME, SALARY FROM WORKER WHERE DESIGNATION = CLERK ; (i) To display the minimum and maximum SALARY SELECT MIN(SALARY), MAX(SALARY) FROM WORKER (i) To display the number of workers in each city. SELECT CITY, COUNT(*) FROM WORKER GROUP BY CITY; 44

45 A Code ActivityName Table: ACTIVITY Stadium Prize Money Schedule Date Participant s Num 1001 Relay 100x4 Star Annex Jan High jump Star Annex Dec Shot Put Super Power Feb Long Jump Star Annex Jan Discuss Throw Super Power Mar ) To display the names of all activities with their Acodes in descending order. 2) To display sum of PrizeMoney for the Activities played in each of the Stadium separately. 3) To count the number of records in the table. 4) To display the content of the Activity table whose ScheduleDate earlier than 01/01/ ) To display the maximum and minimum schedule date from the activity table 45

46 (I) To display the names of all activities with their Acodes in descending order. SELECT ACTIVITYNAME, ACODE FROM ACTIVITY ORDER BY ACTIVITYNAME DESC; (ii) To display sum of PrizeMoney for the Activities played in each of the Stadium separately. SELECT STADIUM, SUM(PRIZEMONEY) FROM ACTIVITY GROUP BY STADIUM; (iii) To count the number of records in the table. SELECT COUNT(*) FROM ACTIVITY; (iv) To display the content of the Activity table whose ScheduleDate earlier than 01/01/2004. SELECT * FROM ACTIVITY WHERE SCHEDULEDATE < 01-JAN-2004 ; (V) To display the maximum and minimum schedule date from the activity table SELECT MAX(SCHEDULEDATE), MIN(SCHEDULEDATE) FROM ACTIVITY 46

47 TABLE : HOSPITAL No Name Age Department Dateofadmin Charge Sex 1 Arpit 62 Surgery 21/01/ M 2 Zayana 18 ENT 12/12/ F 3 Kareem 22 Orthopedic 19/02/ M 4 Abhilash 26 Surgery 24/11/ M 5 Dhanya 24 ENT 20/10/ F 6 Siju 23 Cardiology 10/10/ M 7 Ankita 16 ENT 13/04/ F 8 Divya 15 Cardiology 10/11/ F 9 Nidhin 25 Orthopedic 12/05/ M 10 Hari 28 Surgery 19/03/ M i) To show all information about the patients of cardiology department. ii) To list the name of female patients who are in ENT department. iii) To list names of all patients with their date of admission in ascending order. iv) To count the no of patients with age > 20. v) To disply the sum of charges of each department.. 47

48 i) To show all information about the patients of cardiology department. ii) iii) To list the name of female patients who are in ENT department. To list names of all patients with their date of admission in ascending order. iv) To count the no of patients with age > 20. v) To disply the sum of charges of each department. i. SELECT * FROM HOSPITAL WHERE DEPARTMENT = Cardiology ; ii. iii. SELECT NAME FROM HOSPITAL WHERE SEX = F AND DEPARTMENT = ENT ; SELECT NAME, DATEOFADMIN FROM HOSPITAL ORDER BY DATEOFADMIN; iv. SELECT COUNT(*) FROM HOSPITAL WHERE AGE > 20; v. SELECT DEPARTMENT, SUM(CHARGE) FROM HOSPITAL GROUP BY DEPARTMENT; 48

49 TABLE : TEACHER No Name Age Department Date of Join Salary Sex 1. jigal 34 Computer 10/01/ M 2. Sharmila 31 History 24/03/ F 3. Sandeep 32 Maths 12/12/ M 4. Sangeeta 35 History 01/07/ F 5. Rakesh 42 Maths 05/09/ M 6. Shyam 50 History 27/02/ M 7. Shiv Om 44 Computer 25/02/ M 8. Shalakha 33 Maths 31/07/ F i) To show all information about the teacher of history department. ii) To list the names of female teachers who are in Maths department iii) To list names of all teachers with their date of joining in ascending order. iv) To count the number of teachers with age>23. v) To display the sum of SALARY of each department. 49

50 i) To show all information about the teacher of history department. ii) iii) iv) To list the names of female teachers who are in Maths department To list names of all teachers with their date of joining in ascending order. To count the number of teachers with age>23. v) To display the sum of SALARY of each department. i. SELECT * FROM TEACHER WHERE DEPARTMENT = History ; ii. iii. SELECT NAME FROM TEACHER WHERE SEX = F AND DEPARTMENT = Maths ; SELECT NAME, DATEOFJOIN FROM TEACHER ORDER BY DATEOFJOIN; iv. SELECT COUNT(*) FROM TEACHER WHERE AGE > 23; v. SELECT DEPARTMENT, SUM(Salary) FROM TEACHER GROUP BY DEPARTMENT; 50

51 51

52 ANSWER Cartesian Product Degree = 4 Cardinality = 6 52

53 Write SQL statements for the following: (i) To display NO, NAME, TDATE from the table TRAVEL in descending order of NO. (ii) To display the NAME of all the travellers from the table TRAVEL who are travelling by vehicle with code 101 or 102. (iii) To display the NO and NAME of those travellers from the table TRAVEL who and betweentravelled (iv) To display all the details from table TRAVEL for the travellers, who have travelled distance more than 100 KM in ascending order of NOP. 53

54 ANSWERS: (i) To display NO, NAME, TDATE from the table TRAVEL in descending order of NO. SELECT NO, NAME, TDATE FROM TRAVEL ORDER BYNODESC; (ii) To display the NAME of all the travellers from the table TRAVEL who are travelling by vehicle with code 101 or 102. SELECT NAME FROM TRAVEL WHERE CODE= 101 ORCODE= 102 ; OR SELECT NAME FROM TRAVEL WHERE CODE=101 OR CODE=102; (iii) To display the NO and NAME of those travellers from the table TRAVEL who and betweentravelled SELECT NO, NAME from TRAVEL ; =>TDATEAND =<TDATE WHERE OR SELECT NO, NAME from TRAVEL AND BETWEENTDATEWHERE ; (iv) To display all the details from table TRAVEL for the travellers, who have travelled distance more than 100 KM in ascending order of NOP. SELECT * FROM TRAVEL WHERE KM > 100 ORDERBYNOP; 54

55 Write the result of the following: (v) SELECT COUNT (*), CODE FROM TRAVEL GROUP BY CODE HAVING COUNT(*)>1; (vi) SELECT DISTINCT CODE FROM TRAVEL; (vii) SELECT A.CODE,NAME,VTYPE FROM TRAVEL A,VEHICLE B WHERE A.CODE=B.CODE AND KM<90; (viii) SELECT NAME,KM*PERKM FROM TRAVEL A, VEHICLE B WHERE A.CODE=B.CODE AND A.CODE= 105 ; 55

56 ANSWER: (v) SELECT COUNT (*), CODE FROM TRAVEL GROUP BY CODE HAVING COUNT(*)>1; (vi) SELECT DISTINCT CODE FROM TRAVEL; (vii) SELECT A.CODE,NAME,VTYPE FROM TRAVEL A,VEHICLE B WHERE A.CODE=B.CODE AND KM<90; (viii) SELECT NAME,KM*PERKM FROM TRAVEL A, VEHICLE B WHERE A.CODE=B.CODE AND A.CODE= 105 ; 56

57 SHIVENDER KUMAR BHARDWAJ

Q5 Question Based on SQL & Database Concept Total Marks 8. Theory Question 2 Marks / SQL Commands 6 Marks / Output of commands 2 Marks

Q5 Question Based on SQL & Database Concept Total Marks 8 Theory Question 2 Marks / SQL Commands 6 Marks / Output of commands 2 Marks Q1 Define the Following with example i) Primary Key ii) Foreign Key