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Roby Cigar
Roby Cigar

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Database: DDL, DML, DCL, TCL

Gambar DDL, DML, DCL, TCL

Syntax database management berbasis SQL terbagi menjadi beberapa definisi yaitu: DDL, DML, DCL, TCL.
Berikut ini fungsi keempat definisi tersebut

1. DDL (Data Definition Language) :

Data Definition Language digunakan untuk membuat struktur database.
Contoh syntax dari DDL:

CREATE : to create objects in database
ALTER : alters the structure of database
DROP : delete objects from database
RENAME : rename an objects
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Berikut ini adalah DDL yang membuat table bernama department:

create table department
(dept_name  char(20),
  building   char(15),
  budget     numeric(12,2));
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2. DML (Data Manipulation Language) :

Data Manipulation Language digunakan untuk memanipulasi data yang ada pada database
Contoh perintah DML:

SELECT: retrieve data from the database
INSERT: insert data into a table
UPDATE: update existing data within a table
DELETE: deletes all records from a table, space for the records remain
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Contoh SQL query untuk menemukan nama semua instructors di dalam history department:

select instructor.name
 from instructor
 where instructor.dept_name = 'History';
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3. TCL (Transaction Control Language) :'

Transaction Control Language digunakan untuk mengatur transaksi pada database. TCL nantinya digunakan untuk memanage perubahan pada DML. Dengan kata lain, TCL digunakan bersamaan dengan DML.

Contoh perintah TCL:

COMMIT: Commit command is used to permanently save any transaction
            into the database.
ROLLBACK: This command restores the database to last committed state.
            It is also used with savepoint command to jump to a savepoint
            in a transaction.
SAVEPOINT: Savepoint command is used to temporarily save a transaction so
            that you can rollback to that point whenever necessary.
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DCL (Data Control Language) :

Data Control Language adalah syntax yang digunakan untuk memanajemen akses pada database.

Contoh perintah DCL :

GRANT: allow specified users to perform specified tasks.
REVOKE: cancel previously granted or denied permissions.
The operations for which privileges may be granted to or revoked from a user or role apply to both the Data definition language (DDL) and the Data manipulation language (DML), and may include CONNECT, SELECT, INSERT, UPDATE, DELETE, EXECUTE and USAGE. 
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