Φροντιστήριο SQL

(από το βιβλίο του Date)

Παράδειγμα σχήματος Suppliers and Parts

Εντολές DDL

Εντολές DML

Φροντιστήριο SQL

P# PNAME COLOR WEIGHT CITY

P1 Nut Red 12 London

P2 Bolt Green 17 Paris

P3 Screw Blue 17 Rome

P4 Screw Red 14 London

P5 Cam Blue 12 Paris

P6 Cog Red 19 London

S# SNAME STATUS CITY

S1 Smith 20 London

S2 Jones 10 Paris

S3 Blake 30 Paris

S4 Clark 20 London

S5 Adams 30 Athens

S# P# QTY

S1 P1 300

S1 P2 200

S1 P3 400

S1 P4 200

S1 P5 100

S1 P6 100

S2 P1 300

S2 P2 400

S3 P2 200

S4 P2 200

S4 P4 300

S4 P5 400

Suppliers and Partsdatabase

Φροντιστήριο SQL

CREATE TABLE SP(S# S# NOT NULL,P# P# NOT NULL,QTY QTY NOT NULL,PRIMARY KEY (S#,P#)FOREIGN KEY(S#) REFERENCES S

ON DELETE CASCADE ON UPDATE CASCADE,

FOREIGN KEY(P#) REFERENCES PON DELETE CASCADE ON UPDATE CASCADE,

CHECK (QTY>0 AND QTY<5001) );

Φροντιστήριο SQL

CREATE DOMAIN S# CHAR(5);CREATE DOMAIN P# CHAR(6);CREATE DOMAIN QTY NUMERIC(9);

Φροντιστήριο SQL

Get color and city for “nonParis” parts with weight greater than ten

SELECT P.COLOR, P.CITYFROM PWHERE P.CITY< >`PARIS` AND P.WEIGHT>10;

Φροντιστήριο SQL

For all parts, get the part number and the weight of that part in grams

SELECT P.P#, P.WEIGHT * 454 AS GWTFROM P;

Φροντιστήριο SQL

Get all combinations of supplier and part information such that the supplier and part in question are collocated

SELECT S.S#, S.SNAME, S.STATUS, S.CITY, P.P#, P.PNAME, P.COLOR, P.WEIGHT

FROM S, PWHERE S.CITY=P.CITY;ήSELECT S.S#, S.SNAME, S.STATUS, S.CITY,

P.P#, P.PNAME, P.COLOR, P.WEIGHTFROM S JOIN P ON S.CITY=P.CITY;

Φροντιστήριο SQL

Get all pairs of supplier numbers such that the two suppliers concerned are collocated

SELECT FIRST.S# AS SA, SECOND.S# AS SB FROM S AS FIRST, S AS SECONDWHERE FIRST.CITY=SECOND.CITY AND

FIRST.S# < SECOND.S#;

Φροντιστήριο SQL

Get the maximum and minimum quantity for part P2

SELECT MAX (SP.QTY) AS MAXQ, MIN (SP.QTY) AS MINQ

FROM SPWHERE SP.P# = `P2`;

Φροντιστήριο SQL

For each part supplied, get the part number and the total shipment quantity

SELECT SP.P#, SUM (SP.QTY) AS TOTQTY FROM SPGROUP BY SP.P# ;ήSELECT P.P#, (SELECT SUM (SP.QTY)

FROM SPWHERE SP.P#=P.P#) AS TOTQTY

FROM P;

Φροντιστήριο SQL

Get part numbers for all parts supplied by more than one supplier

SELECT SP.P#FROM SPGROUP BY SP.P# HAVING COUNT(SP.S#) >1;

Φροντιστήριο SQL

Get supplier names for suppliers who supply part P2

SELECT DISTINCT S.SNAMEFROM SWHERE S.S# IN (SELECT SP.S#

FROM SPWHERE SP.P# = `P2`);

ήSELECT DISTINCT S.SNAMEFROM S, SPWHERE S.S# =SP.S# AND SP.P# = `P2`;ή

Φροντιστήριο SQL

Get supplier names for suppliers who supply part P2

SELECT DISTINCT S.SNAMEFROM SWHERE EXISTS

(SELECT *FROM SPWHERE SP.S#=S.S# AND SP.P# = `P2`);

Φροντιστήριο SQL

Get supplier names for suppliers who do not supply part P2

SELECT DISTINCT S.SNAMEFROM SWHERE NOT EXISTS

(SELECT *FROM SP WHERE SP.S#=S.S# AND SP.P# = `P2`);

ήSELECT DISTINCT S.SNAMEFROM SWHERE S.S# NOT IN

(SELECT SP.S#*FROM SPWHERE SP.P# = `P2`);

Φροντιστήριο SQL

Get supplier names for suppliers who supply at least one red part

SELECT DISTINCT S.SNAMEFROM SWHERE S.S# IN (SELECT SP.S#

FROM SPWHERE SP.P# IN

(SELECT P.P# FROM PWHERE P.COLOR= `Red`));

Φροντιστήριο SQL

Get supplier names for suppliers who supply all parts

SELECT DISTINCT S.SNAMEFROM SWHERE NOT EXISTS

(SELECT *FROM PWHERE NOT EXISTS

(SELECT * FROM SPWHERE SP.S#=S.S# AND SP.P#= P.P#));

Φροντιστήριο SQL

Get supplier names for suppliers who supply all parts

SELECT DISTINCT S.SNAMEFROM SWHERE (SELECT COUNT(SP.P#)

FROM SPWHERE SP.S#=S.S#) =

(SELECT COUNT (P.P#)FROM P);

Φροντιστήριο SQL

Get supplier numbers for suppliers with status less that the current maximum status in the S table

SELECT S.S#FROM SWHERE S.STATUS <

(SELECT MAX(S.STATUS)FROM S);

Φροντιστήριο SQL

Get part numbers for parts that either weight more than 16 pounds or are supplied by supplier S2, or both

SELECT P.P#FROM PWHERE P.WEIGHT > 16UNIONSELECT SP.P#FROM SPWHERE SP.S#=`S2`);

Φροντιστήριο SQL

INSERTINTO P(P#,PNAME,COLOR,WEIGHT,CITY)VALUES (`P8`, `Sprocket`, `Pink`, 14, `Nice`);

INSERTINTO TEMP(S#,CITY)

SELECT S.S#, S.CITYFROM SWHERE S.STATUS>15;

Φροντιστήριο SQL

UPDATE PSET COLOR=`Yellow`, WEIGHT=P.WEIGHT+5 WHERE P.CITY=`Paris`;

UPDATE PSET CITY = (SELECT S.CITY

FROM SWHERE S.S#=`S5`)

WHERE P.COLOR=`Red`;

Φροντιστήριο SQL

DELETEFROM SPWHERE `London` =

(SELECT S.CITYFROM SWHERE S.S#=SP.S#);

Φροντιστήριο SQL

For all red and blue parts such that the total quantity supplied is greater than 350 (excluding from the total all shipment for which the quantity is less than or equal to 200), get the part number, the weight in grams, the color, and the maximum quantity supplied of that part

Φροντιστήριο SQL

SELECT P.P#, `Weight in grams =` AS TEXT1, P.WEIGHT * 454 AS GMWT, P COLOR,

`Max Quantity=` AS TEXT2, MAX(SP.QTY) AS MQY

FROM P, SPWHERE P.P#=SP.P# AND SP.QTY>200 AND

(P.COLOR=`Red` OR P.COLOR=`Blue`)GROUP BY P.P#, P.WEIGHT, P.COLORHAVING SUM(SP.QTY) > 350;

Φροντιστήριο SQL

P# TEXT1 GMWT COLOR TEXT2 MQY

P1 Weight in

grams = 5448 Red

Max quantity = 300

P5 Weight in

grams = 5448 Blue

Max quantity = 400

P3 Weight in

grams = 7718 Blue

Max quantity = 400

Φροντιστήριο SQL

Get part names for parts whose weight is greater that that of every blue part

SELECT DISTINCT PX.PNAMEFROM P AS PXWHERE PX.WEIGHT > ALL

(SELECT PY.WEIGHTFROM P AS PYWHERE PY.COLOR=`Blue`);