5Basic SQL – MEF Materi Sistem dan Teknologi Informasi | Blog Mas'ud Effendi Basic SQL MEF

SQL (Structured Query Language)

SQL

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Structured Query Language

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Awalnya disebut SEQUEL

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DB/2, SQL/DS dan oracle saat pertama kali

SQL

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Bahasa standar yang digunakan untuk berkomunikasi dengan

database relasional

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Dapat diterapkan untuk banyak database management system

(DBMS) seperti MySQL, Microsoft SQL Server, Oracle,

DB2, PostgreSQL

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Perintah standar SQL pada beberapa DBMS hampir sama,

Klasifikasi SQL

Data Definition Language (DDL) Data Manipulation Language (DML) Data Control Language (DCL)

SQL Table Creation and Population Commands

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Mendefinisikan table (relation)

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Mengisi tabel (relation)

create table tablename (columnname datatype {,columnname datatype})

insert into tablename (columnname {,columnname}) values (value {,value})

create table item (item_nr varchar2(3), description

varchar2(10), pack_unit integer, unit_price number(5,2))

DELETE

Baris dapat dihapus dengan operasi DELETE

_{DELETE FROM tablename WHERE condition}

The SQL Retrieval Statement

Operasi SELECT…..

Corrname



coorelation name



alias

SQL select Example

Berikut adalah hasil operasi SELECT berdasarkan

relation/tabel yang telah dibuat dengan operasi

CREATE dan INSERT

select * from item;

Item_Nr Description Pack_Unit Unit-Price

SQL select Example

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Setelah lebih banyak entry

select * from item;

Item_Nr Description Pack_Unit Unit-Price

SQL - A Simple PROJECTION

select item_nr, description from item;

Item_Nr Description

SQL - A SELECTION

select * from item

where item_nr > 'I30' and item_nr < 'I90';

Item_Nr Description Pack_Unit Unit-Price

I35 Nut 100 0.05

I87 Washer 100 0.05

I56 Hammer 1 14.95

I34 Nail 20 3.45

SQL - The ORDER BY Clause

Item_Nr Description Pack_Unit Unit-Price

I56 Hammer 1 14.95

I34 Nail 20 3.45

I35 Nut 100 0.05

I87 Washer 100 0.05

select * from item

where item_nr > 'I30’ and item_nr < 'I90'

SQL - RESTRICTION and PROJECTION

select item_nr,description from item where item_nr > 'I30'

and item_nr < 'I90’;

Item_Nr Description

I56 Hammer

I34 Nail

I35 Nut

The Other Two Tables in the Sample Data

Model . . .

Item_Nr Supp_Nr

I26 S45

Supp_Nr Supp_Name

S21 Allgoods

S34 Sumgoods

An SQL JOIN (ITEM to ITEMSUPPLIER)

select * from item i, itemsupplier i_s where i.item_nr = i_s.item_nr;

Item_Nr Description Pack_Unit Unit-Price Item_Nr Supp_Nr

Three Tables, Two Joining Conditions

select * from item i, itemsupplier i_s, supplier s where i.item_nr = i_s.item_nr

and s.supp_nr = i_s.supp_nr;

Item_Nr Description Pack_Unit Unit-Price Item_Nr Supp_Nr Supp_Nr Supp_Name

Two Joins, a Selection and a Projection

select i.item_nr, description, s.supp_nr, supp_name from item i, itemsupplier i_s, supplier s

where i.item_nr = i_s.item_nr and s.supp_nr = i_s.supp_nr

and i.item_nr > 'I30' and i.item_nr < 'I90'

Item_Nr Description

Supp_Nr Supp_Name

I35

Nut

S45

Fewgoods

I87

Washer

S21

Allgoods

I87

Washer

S34

Sumgoods

I56

Hammer

S21

Allgoods