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DCL :-

create identified by ;
//it will create a new user in SQL

Grant connect,resource to ;
//this will give permission to access our account by our user name


DDL :-

create ([[column_name data_type],...]);
//Here we can give any number of columns;

alter table
add([[column_name data_type],...]);
//if we want to add new column in our table

alter table
modify([[column_name modified_column_name],...]);
//if we want to modify a column name

truncate table ;
//it will delete all rows from our table.

drop table ;
//it will delete all rows alongwith columns i.e. schema(or structure) of our table


DML :-


select from ;
//it will display all data from specified column names.
//if we want all columns we include * at the column name

insert into values([[column_name value]...]);
or
insert into values();

delete from [from where ];
//if we doesn't specify any condition it will acts like truncate command i.e. it will delete all rows.
//if we specify a condition it will delete particular columns which satisfied by conditions


Constraints :-
we can assign some constraint at the time of creation or after creation


create table ([column_name data_type not null],...]);
//this will create a column with specified column with not null property i.e. it doesn't take any null values

alter table modify not null;
//this will modifies a already created column to not null property.

create table ([[column_name data_type constraint check ]...]);
//this will create column(s) with specified constraint


Function:-

create or replace function[schema]
([[ in ]...]) return IS
variable declaration;
constant declaration;
BEGIN

[EXCEPTION]

END; /

//this is for creating function in PL/SQL

drop function ;
//this will delete specified function.


Trigger :-

CREATE OR REPLACE TRIGGER
[{before,after}]{DELETE,INSERT,UPDATE [of columns...]} ON
[REFERENCING {OLD AS OLD,NEW AS NEW}]
[FOR EACH ROW [when ]]
DECLARE

BEGIN

[EXCEPTION]

END;


Cursor :-
Cursor Declaration:

CURSOR IS ;
/* Here most time SQL command is select */

Opening a cursor:

OPEN ;

Fetching a record from the cursor:

FETCH into ;

Closing a cursor:

CLOSE ;


Parameterized Cursor:-

CURSOR () is ;
Open cursor_name([value/variable/expression]);


For Loop :-

for memvar in
Loop
[...
...
]
ENd LOOP;