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e What fs S8L?
WY SOL stands for Structured Query Language -
It is used for sting and managing dara in
velational database management system (RDBMS)
© SQL Commands :
@ Select - Extract data from database.
VY The data veturned ts stored in @ vesult
fable , called the wesulf— Set.
LicomeR (LINKED IA )-
SELECT Syntax Notes GALLERY (TELEGRAM).
——
| SELECT Colurnn1, Column2.....
FROM table—- name,
Here , column 1, Column2,.... ave the Field
names of the table you want +o select dara
From.
IF you want fo <select all the Fields
available §{n the table use the
Fo\lowing Syntax °
[ serect * From table — name
L aru come (LinikeDin).
SELECT columns Example
Cs folowing S@L statement Selects -tne
“customer Name", “city! pana “country "columns
from the “Customers” table :
Example
SELECT Customer niame, city ,
Countvy FROM Customers :
ATUL MOK
r NOTES GALLERY (receGRam)
® UPDATE
Updates data in @ database.
The UPDATE Srerement is used 10 modify the
existing yecords jn A table.
UPpaATE Syntax f
UPDATE table_ name
SET Columni = value,
column 2 = vaqiue 2,..
WHERE Condition;
Example
UPDATE Customer
SET Contac Name = ‘Kanth’
Clty =Fyank Furt
TUL KOMI CLIN IKEDIn),
ALTER TABLE — ADD column.
ALTER TABLE table name
APD Column— name data type
Example
ALTER TABLE Customer
ADD Gmail Vaychar (255 )
DROP column
ALTERTABLE table.nIme
DRoP Column column. name ;
Example
ALTER TABLE Customers
DROP COLUMN Emad! 3
L :
NOTES GALLERY (TELEGRAM),
@ CREATE TABLE
Creates Q new table.
The CREATE TABLE starement fs Used to create q
new table in a datanase.
_ Syntax
CREATE TABLE table_name (
Columnt datatype »
column 2 datatype ,
column 8 datatyre ,
ae
Continue ap
ATUL KomA (Litk Epiat)-
|
— example
CREATE TABLE Person (
Se Persona Dee ine
LactnName Vaychay (265 ),
Fiyst lame Vaychay (26s J,
Addyess Varchar (255 ),
City Varchay (285 )
a
ATUL Kum (LINKEDIN) -
NOTES GALLERY (TELEGRAM)
@ DROP TABLE
eletes @ table.
The OP TABLE statement js used to dyop an
existing table in a data base.
Syntax
DROP TABLE table. name;
Example
DROP TABLE Sniprers 5
@ CREATE INDEX
Creates an Index ( Search key )
The Create In étatement ig used fo Create
Indexes In table.
Indexes aye used to vetyive data from the data base
More quiciy than Otherwise.
The usevs cannot see the Indexes, they ave just
used to Speed up searches / queries.
Continue ——>
ATUL KUMAR LUNKEDIALD.
CREATE INDEx Index. name
ON table. name
C column 4, column], 3
CREATE INDEX Idx _ ]astname
ON Pexcon( Lastnlame, First Name) ;
MPR LLIN KEDIALD
NOTES GALLERY (TELEGRAM),
e DROP INDEX. INDEX
Deletes on Index
“Tne _DeoP INDEX Statement fs used to delete an
index jn aq table.
ALTER TABLE table_naqme.
| DROP INDEX Index Name 5
ATUL KUMAR LLINKEDIAL).
