STRUCTURED QUERY LANGUAGE SQL part1.pdf · 04.11.2015 1 STRUCTURED QUERY LANGUAGE Database systems Query defines price. Russian proverb Outline Database systems Historical note and

04.11.2015

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STRUCTURED

QUERY LANGUAGE

Database systems

Query defines price. Russian proverb

Outline

Database systems

Historical note and structure

Data manipulation with SQL

Data definition with SQL

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© M. Zymbler

SQL

© M. ZymblerDatabase systems

SQL (Structured Query Language) is a standard

language of relational databases.

SQL is descriptive, not programming language.

SQL describes only the resulting relation that DBMS should

output

SQL does not describe how DBMS should obtain the

resulting relation

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SQL historical note


Year Name Features

1970 SEQUEL Language of IBM System R DBMS (SEQUEL – Structured

English QUEry Language).

1986 SQL-86 Accepted by ANSI in 1986 and approved by ISO in 1987.

1989 SQL-89 Improvement of previous version.

1992 SQL-92 Significant improvement of previous version.

1999 SQL:1999

(or SQL-3)

Added: regular expressions, recursive queries, triggers, non-scalar

data types, some OO-features.

2003 SQL:2003 Added: XML data type, OLAP functions, sequences.

2006 SQL:2006 Improved: working with XML data. Added: XQuery in SQL

queries.

2008 SQL:2008 Improved: OLAP functions, SQL:2003 errors fixed.

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SQL structure


SQL consists of the following parts: Data Definition Language, DDL

Data Manipulation Language, DML

Data Control Language, DCL

Transaction Control Language, TCL

SQL/PSM (Persistent Stored Modules), procedural extension of SQL.

DDL create, drop, alter tables

DML select rows from table(s)

insert rows into table

update rows in table

delete rows from table

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Database structure for examples


S – Suppliers

P – Parts

SP – Supplies

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Selection of rows


select [distinct] list of selected columns

from list of tables

[where condition for rows]

[order by list of columns to be ordered]

[group by list of grouped columns]

[having condition of groups];

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Selection with many conditions


Get list of parts' names and

prices where parts are not

from Paris and have weight

more than 10.

select P.Name, P.Price

from P

where P.City<>'Paris' and

P.Weight>10;

PID Name City Weight Price

P1 Bolt Paris 15 40

P34 Screw Moscow 29 33

P22 Screw-nut Chelyabinsk 20 24

P45 Screw Odessa 14 33

P

Name Price

Screw 33

Screw-nut 24

Screw 33

Result

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Selection without duplicates



prices without repetition where

parts are not from Paris and

have weight more than 10, and

sort resulted list by part name.

select distinct P.Name, P.Price

from P


P.Weight>10

order by P.Name;


P1 Bolt Paris 15 40




P

Name Price

Screw 33

Screw-nut 24

Result

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Selection with ordering



prices without repetition where

parts are not from Paris and

have weight more than 10, and

sort resulted list descending by

price.

select distinct P.Name, P.Price

from P


P.Weight>10

order by P.Price desc;


P1 Bolt Paris 15 40




P

Name Price

Screw 33

Screw-nut 24

Result

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Selection with calculations


Get part names and prices in €.

select distinct P.Name,

P.Price/40.00 as Price_EUR

from P;


P1 Bolt Paris 15 80




P

Result

Name Price_EUR

Bolt 2

Screw 3

Screw-nut 0.5

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Selection from joining tables


Get list of all the pairs of suppliers and parts from the same city.

select S.SID, S.SName, S.City, P.PID, P.PNamefrom P, Swhere S.City=P.City;

select S.SID, S.SName, S.City, P.PID, P.PNamefrom S join P using City;

select S.SID, S.SName, S.City, P.PID, P.PNamefrom S natural join P;

PID PName City Weight Price

P1 Bolt Paris 15 72

P34 Screw Chelyabinsk 29 108



P

Result

SID SName City PID PName

S2 KGB Ltd Chelyabinsk P34 Screw

S2 KGB Ltd Chelyabinsk P22 Screw-nut

SID SName City Rating

S1 Bender Chernomorsk 15

S34 IT-monster Moscow 29

S2 KGB Ltd Chelyabinsk 20

S

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Selection of all the columns


Get full info (all the columns)

about parts.

select P.*

from P;

select *

from P;


P1 Bolt Paris 15 72




P

Result


P1 Bolt Paris 15 72




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Selection from self-joining table


Get all the pairs of suppliers'

IDs where first and second

supplier are from the same

city.

select First.SID as SA,

Second.SID as SB

from S as First, S as Second

where First.City=Second.City

and SA<>SB;

SID Name City Rating




S7 AnyImport Moscow 31

S5 Suspense+ Chelyabinsk 2

S4 Horns&Hoofs Chernomorsk 15

S

SA SB

S1 S4

S4 S1

S3 S7

S7 S3

S2 S5

S5 S2

Result

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Selection of aggregations


Get quantity of suppliers.

select 'Quantity' as Text, count(*)

as CountS

from S;

SID Name City Rating




S7 AnyImport Moscow 31

S5 Suspense+ Chelyabinsk 2

S4 Horns&Hoofs Chernomorsk 15

S

Text CountS

Quantity 6

Result

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Selection of aggregations


Get min, max and average

quantity of supplements of

part with P1 ID.

select max(SP.Qty) as MaxQ,

min(SP.Qty) as MinQ,

avg(SP.Qty) as AvgQ

from SP

where SP.PID='P1';

SID PID Qty

S1 P1 10

S3 P2 20

S2 P1 30

S7 P1 40

S5 P3 50

S4 P1 80

SP

MaxQ MinQ AvgQ

80 10 40

Result

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Selection and grouping rows


Get an ID and quantity of

supplements for every part.

select SP.PID, sum(SP.Qty) as Total

from SP

group by SP.PID;

select P.PID,

(select sum(SP.Qty)

from SP

where SP.PID=P.PID) as Total

from P;

SID PID Qty

S1 P5 10

S3 P2 20

S2 P4 30

S7 P1 40

S5 P5 20

S5 P3 50

S8 P2 30

S4 P1 80

SP

PID Total

P5 30

P2 50

P4 30

P1 120

P3 50

Result

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Selection and grouping rows


Get part IDs that are supplied by more than

one supplier.

select SP.PID

from SP

group by SP.PID

having count(SP.SID)>1;

SID PID Qty

S1 P5 10

S3 P2 20

S2 P4 30

S7 P1 40

S5 P4 50

S8 P2 30

SP

PID

P2

P4

Result

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Selection and grouping with conditions


Get part names that are supplied

by more than one supplier.

select distinct P.Name

from P

where P.PID in

(select SP.PID

from SP

group by SP.PID

having

count(SP.SID)>1);

SID PID Qty

S1 P5 10

S3 P2 20

S2 P4 30

S7 P1 40

S5 P4 50

S8 P2 30

SP

Name

Screw-nut

Result

PID Name

P1 Bolt

P2 Screw-nut

P3 Screw

P4 Screw-nut

P5 Angle-part

P

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Selection using IN operation


Get names of suppliers that

supply part with P2 ID.

select distinct S.Name

from S

where S.SID in

(select SP.SID

from SP

where SP.PID='P2');

SID PID Qty

S1 P5 10

S3 P2 20

S2 P2 30

S7 P1 40

S5 P4 50

S8 P2 30

SP

Name

IT-monster

AnyImport

Result

SID Name

S1 Suspense +

S2 IT-monster

S3 AnyImport

S5 MacroHard

S7 Vegetable Inc.

S8 AnyImport

S

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Selection using EXISTS operation





from S

where exists (

select *

from SP

where SP.SID=S.SID and

SP.PID='P2');

SID PID Qty

S1 P5 10

S3 P2 20

S2 P2 30

S7 P1 40

S5 P4 50

S8 P2 30

SP

Name

IT-monster

AnyImport

Result

SID Name

S1 Suspense +

S2 IT-monster

S3 AnyImport

S5 MacroHard

S7 Vegetable Inc.

S8 AnyImport

S

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Selection using subqueries





from S,

(select S.SID

from S, SP

where SP.SID=S.SID and

SP.PID='P2') as SIDs_P2

where S.SID=SIDs_P2.SID;

SID PID Qty

S1 P5 10

S3 P2 20

S2 P2 30

S7 P1 40

S5 P4 50

S8 P2 30

SP

Name

IT-monster

AnyImport

Result

SID Name

S1 Suspense +

S2 IT-monster

S3 AnyImport

S5 MacroHard

S7 Vegetable Inc.

S8 AnyImport

S

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Selection using , operation





from S, SP

where S.SID=SP.SID

and SP.PID='P2';

SID PID Qty

S1 P5 10

S3 P2 20

S2 P2 30

S7 P1 40

S5 P4 50

S8 P2 30

SP

Name

IT-monster

AnyImport

Result

SID Name

S1 Suspense +

S2 IT-monster

S3 AnyImport

S5 MacroHard

S7 Vegetable Inc.

S8 AnyImport

S

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Selection





from S

where 0 <

(

select count(*)

from SP

where S.SID=SP.SID

and SP.PID='P2'

);

SID PID Qty

S1 P5 10

S3 P2 20

S2 P2 30

S7 P1 40

S5 P4 50

S8 P2 30

SP

Name

IT-monster

AnyImport

Result

SID Name

S1 Suspense +

S2 IT-monster

S3 AnyImport

S5 MacroHard

S7 Vegetable Inc.

S8 AnyImport

S

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Selection using ANY operation





from S

where 'P2' = any

(

select SP.PID

from SP

where S.SID=SP.SID

);

SID PID Qty

S1 P5 10

S3 P2 20

S2 P2 30

S7 P1 40

S5 P4 50

S8 P2 30

SP

Name

IT-monster

AnyImport

Result

SID Name

S1 Suspense +

S2 IT-monster

S3 AnyImport

S5 MacroHard

S7 Vegetable Inc.

S8 AnyImport

S

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Selection using grouping




select S.Name

from S, SP

where S.SID=SP.SID and

SP.PID='P2'

group by S.Name;

SID PID Qty

S1 P5 10

S3 P2 20

S2 P2 30

S7 P1 40

S5 P4 50

S8 P2 30

SP

Name

IT-monster

AnyImport

Result

SID Name

S1 Suspense +

S2 IT-monster

S3 AnyImport

S5 MacroHard

S7 Vegetable Inc.

S8 AnyImport

S

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Selection


Get names of suppliers that do not supply part with P2 ID. select distinct S.Name

from Swhere not exists (select *from SPwhere SP.SID=S.SID and P.PID='P2');

select distinct S.Namefrom Swhere S.SID not in (select SP.SIDfrom SPwhere SP.PID='P2');

SID PID Qty

S1 P5 10

S3 P2 20

S2 P2 30

S7 P1 40

S5 P4 50

S8 P2 30

SP

Name

Vegetable Inc.

MacroHard

Result

SID Name

S1 Vegetable Inc.

S2 IT-monster

S3 AnyImport

S5 MacroHard

S7 Vegetable Inc.

S8 AnyImport

S

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Selection


Get names of suppliers that supply red parts. select distinct S.Name

from Swhere S.SID in

(select SP.SIDfrom SPwhere SP.PID in

(select P.PIDfrom Pwhere P.Color='Red'));

select distinct S.Namefrom S, P, SPwhere S.SID=SP.SID andSP.PID=P.PID and P.Color='Red';

SID PID Qty

S1 P5 10

S3 P2 20

S2 P2 30

S7 P1 40

S5 P4 50

S8 P2 30

SP

Name

Vegetable Inc.

MacroHard

Result

SID Name

S1 Vegetable Inc.

S2 IT-monster

S3 AnyImport

S5 MacroHard

S7 Vegetable Inc.

S8 AnyImport

S

PID Color

P1 Red

P2 Green

P3 Blue

P4 Red

P5 Red

P

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Selection using NOT EXISTS


Get names of suppliers that supply all the parts.

select distinct S.Namefrom Swhere not exists (

select *from Pwhere not exists (

select *from SPwhere SP.SID=S.SID

and SP.PID=P.PID));

SID PID Qty

S1 P1 10

S1 P2 20

S1 P3 30

S2 P1 40

S2 P2 50

S2 P3 30

S3 P3 20

S7 P2 100

SP

Name

IT-monster

Result

SID Name

S1 IT-monster

S2 IT-monster

S3 AnyImport

S5 MacroHard

S7 Vegetable Inc.

S8 AnyImport

S

PID

P1

P2

P3

P

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Selection


Get names of suppliers that supply

all the parts.


from S

where

(select count(SP.PID)

from SP

where SP.SID=S.SID) =

(select count(P.PID)

from P);

SID PID Qty

S1 P1 10

S1 P2 20

S1 P3 30

S2 P1 40

S2 P2 50

S2 P3 30

S3 P3 20

S7 P2 100

SP

Name

IT-monster

Result

SID Name

S1 IT-monster

S2 IT-monster

S3 AnyImport

S5 MacroHard

S7 Vegetable Inc.

S8 AnyImport

S

PID

P1

P2

P3

P

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Selection using UNION operation


Get names of parts that either have

price more than 100, or are supplied

by suppliers from Chelyabinsk, or

both.

select P.Name

from P, SP

where SP.PID=P.PID and P.Price>100

union

select P.Name

from S, P, SP

where SP.PID=P.PID and SP.SID=S.SID

and S.City='Chelyabinsk';

SID PID Qty

S1 P1 10

S2 P1 40

S3 P5 20

S7 P2 100

S8 P2 300

S5 P4 500

SP

Name

Screw-nut

Bolt

Screw

Result

SID City

S1 Moscow

S2 Uryupinsk

S3 Chelyabinsk

S5 Odessa

S7 Chelyabinsk

S8 Chelyabinsk

S

PID Name Price

P1 Bolt 200

P2 Screw-nut 10

P3 Bolt 150

P4 Angle-part 15

P5 Screw 130

P

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Selection using INTERSECT operation


Get names of parts that have price more than 100 and are supplied by suppliers from Chelyabinsk.

select P.Namefrom P, SPwhere SP.PID=P.PID and P.Price>100intersectselect P.Namefrom S, P, SPwhere SP.PID=P.PID andSP.SID=S.SID andS.City='Chelyabinsk';

SID PID Qty

S1 P1 10

S2 P1 40

S3 P5 20

S7 P2 100

S8 P5 300

S5 P4 500

SP

Name

Bolt

Screw

Result

SID City

S1 Moscow

S2 Uryupinsk

S3 Chelyabinsk

S5 Odessa

S7 Chelyabinsk

S8 Chelyabinsk

S

PID Name Price

P1 Bolt 200

P2 Screw-nut 10

P3 Bolt 150

P4 Angle-part 15

P5 Screw 130

P

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Selection using EXCEPT operation


Get names of parts that have price

more than 100 and are not supplied

by suppliers from Chelyabinsk.

select P.Name

from P, SP

where SP.PID=P.PID and P.Price>100

except

select P.Name

from S, P, SP

where SP.PID=P.PID and SP.SID=S.SID

and S.City='Chelyabinsk';

SID PID Qty

S1 P1 10

S2 P3 40

S3 P5 20

S7 P2 100

S8 P5 300

S5 P4 500

SP

Name

Bolt

Result

SID City

S1 Moscow

S2 Uryupinsk

S3 Chelyabinsk

S5 Odessa

S7 Chelyabinsk

S8 Chelyabinsk

S

PID Name Price

P1 Bolt 200

P2 Screw-nut 10

P3 Bolt 150

P4 Angle-part 15

P5 Screw 130

P

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Selection using ALL operation


Get names of parts that have price

more than price of all parts from

Chelyabinsk.

select distinct P.Name

from P

where P.Price > all

(select P.Price

from P

where P.City='Chelyabinsk'); Name

Timber

Screw-nut

Bolt

Result

PID Name Price City

P1 Bolt 30 Chelyabinsk

P2 Timber 99 Shepetovka

P3 Bolt 50 Chelyabinsk

P4 Angle-part 40 Odessa

P5 Screw 23 Chelyabinsk

P6 Screw-nut 77 Moscow

P7 Bolt 88 Kopeisk

P

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Selection and conditional output


Get IDs, names and rating by words.

select S.SID, S.Name,

case

when S.Rating < 10 then 'Problematic'

when S.Rating < 15 then 'Neutral'

when S.Rating < 20 then 'Acceptable'

when S.Rating < 25 then 'Reliable'

end as Rating

from S;

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Insertion rows into a table


insertinto table [list of columns]values (list of values) | select query;

Insert one row insert

into P (PID, Color, Name, Weight, City)values ('P10', 'White', 'Timber', 3, 'Moscow');

Insert more than one row insert

into AvgRatings (City, Rating)select S.City, avg(S.Rating)from Sgroup by S.City;

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Update rows in a table


update tableset list of modified columns[where condition];

Update one row update S

set S.SID='S007', S.Name='Bond'where S.SID='S7';

Update more than one row update S

set S.Rating=S.Rating+1where S.Rating<(select avg(S.Rating) from S);

update Pset P.City = (select S.City from S where S.SID='S007')where P.Color='White';

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Delete rows from a table


delete [*]from table[where condition];

Delete one row

deletefrom Swhere S.SID='S007';

Delete more than one row

deletefrom Swhere S.Rating<(select avg(S.Rating) from S);

delete from SP;

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Creating tables


create table S (SID char(4) primary key,Name char(10) not null,City char(10) not null,Rating int not null);

create table P (PID char(4) primary key,Name char(10) not null,City char(10) not null,Price int not null,Color char(10) not nullWeight float not null);

create table SP (SID char(4),PID char(4),Qty int not null,primary key (SID, PID),foreign key (SID)references S (SID)on delete cascade*

on update cascade,foreign key (PID)references P (PID)on delete cascadeon update cascade,

check (Qty>0));

*Available modes are cascade, set null, set default, no action.

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Alter and drop tables


alter table P

add column Discount float default 0;

alter table P

add constraint check (Price>0),

add constraint check (Weight>0);

drop table S restrict;

drop table SP cascade;

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SQL/PSM: an example


create procedure Statistics(aliveS out number, deadS out number,aliveP out number, deadP out number) as

declaret number;

beginselect count(*) into t from S;select count(*) into aliveS from SPwhere SP.SID=S.SID;deadS:=t-aliveS;select count(*) into t from P;select count(*) into aliveP from SPwhere SP.PID=P.PID;deadP:=t-aliveP;

end;

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Documents

STRUCTURED QUERY LANGUAGE SQL part1.pdf · 04.11.2015 1 STRUCTURED QUERY LANGUAGE Database systems Query defines price. Russian proverb Outline Database systems Historical note and