1. PL/SQL blocks allow declaring variables, cursors, and exceptions before executing SQL and PL/SQL statements. Variables can be scalar, composite like records, or reference types like cursors. 2. Procedures and functions are created using CREATE OR REPLACE and can contain PL/SQL blocks. 3. Records are used to store multiple fields of different types, like table rows. PL/SQL tables allow storing multiple values of the same type in an indexed collection. 4. Variables can be accessed in nested blocks, with outer variables referenced explicitly.

1. Anar Godjaev
http://anargodjaev.wordpress.com/
PL/SQL Blocks
declare
--<Variables, Cursors, user defined exception>
begin
--<Sql statements>
--<PL/SQL statements>
exception
When <exception name> then
--<Actions to perform when errors, occur>
end;
EX:
declare
v_variablevarchar2(15);
begin
selectcolumn_name
intov_variable
fromtable_name;
exception
whenothers then
null;
end;
create or replace procedure <procedure_name> as
--<declare any variables here>
begin
null;
end;
create or replace function <function_name> return <datatype> as
--<declare any veriables here>
begin
return<value>;
end;
Variable Types:
scalar (single value) -- varchar2, number, date, subtype
composite (records) -- record, plsql table
reference (pointer) -- ref cursor
LOB (large objects) -- BLOB, CLOB, LOB
Bind variables -- variables defined outside plsql block, ex: .NET, Java, sqlplus
Scalar data types:

2. Anar Godjaev
http://anargodjaev.wordpress.com/
Char, varchar2, long, number, binary_integer, boolean, date, timestamp, timestamp
withtimezone, timestamp with local time zone
declare
str_jobvarchar2(15);
int_countbinary_integer := 0;
n_tot_salnumber(9,2);
cons_numconstant number(3,2) := 8.25;
b_validboolean not null default true;
_name employees.last_name%TYPE;
date_dtdate := sysdate+7;
subtypetype_my_varchar varchar2(100);
type_my_charmy_varchar;
EX:
declare
n_deptnonumber(4); --departments.department_no%TYPE
n_location_idnumber(4); --departments.locations_id%TYPE
begin
selectdepartment_id, location_id
intov_deptno, v_location_id
fromdepartments where department_name= 'Sales';
end;
Composite data types:
Records:
rec_tbl_based is table_name%ROWTYPE;
rec_cur_based is cur_name%ROWTYPE;
typetype_rec_var_based is (field1 datatype1, field2 datatype2, .. )
rec_my_recordtype_rec_var_based
selectcol_name into rec_my_record.col_name from table_name;
selectrec_my_record.col_name from dual;
EX:
declare
rec_empemployees%ROWTYPE;
n_employee_numbernumber := 1024;
begin
select* into emp_recfrom employees
whereemployee_id= n_employee_number;
insert into retired_emps
(emp_no, ename, job, mng, hire_date, leave_date, sql, comm, rept_no)
values
(emp_rec.employee_id, emprec.lastname,...);
commit;
end;

3. Anar Godjaev
http://anargodjaev.wordpress.com/
EX:
declare
typeemp_record_typeis record
(
last_namevarchar2(25),
job_idvarchar2(10),
salarynumber(8,2)
);
emp_recordemp_record_type;
begin
emp_record.last_name:= 'ERGEM';
dbms_output.put_line(emp_record.last_name);
end;
Plsql Tables:
typetype_tbl_city_codes is table of varchar2(50);
typetype_tbl_city_codes is table of t_city.code%TYPE;
typetype_tbl_based_on_cur is table of type_rec_var_based
[index by binary integer];
tbl_city_codestype_tbl_city_codes;
select code into tbl_city_codes(15) from t_city where city_id=15;
selecttbl_city_codes(15) from dual;
typeename_table_type is table of employees.lastname%TYPE
index by binary_integer;
ename_tableename_table_type;
EX:
declare
-- declare the table type
typeename_table_typeis table of
varchar2(100);--employees.last_name%TYPE index by binary integer;
typehiredate_table_typeis table of
dateindex by binary_integer;
-- declare the table type variable
ename_tableename_table_type;
hiredate_tablehiredate_table_type;
begin
-- initialize the table by a call to the constructor
ename_table:= ename_table_type();
-- extend the table
ename_table.extend(1);
-- assign a value
ename_table(1) := 'cameron';
-- indexed tables do not need initializing and extending

4. Anar Godjaev
http://anargodjaev.wordpress.com/
-- hiredate_table := hiredate_table_type();
-- hiredate_table.extend(10);
hiredate_table(8) := sysdate + 7;
ifename_table.exists(1) then
--insert into ...
dbms_output.put_line(ename_table(1));
dbms_output.put_line(hiredate_table(8));
end if;
end;
Pl/SQL table attributes:
Exists [(n)]
Count
First
Last
Prior [(n)]
Next [(n)]
Trim [(n)] -- rename one element from end table
Delete [(n)] -- remove elements
EX:
declare
typeemp_table_typeis table of employees%ROWTYPE
index by binary_integer;
my_emp_tableemp_table_type;
v_countnumber(3) := 104;
begin
fori in 10.. v_countloop
select* into my_emp_table(i) from employees
whereemployee_id= i;
end loop;
fori in my_emp_table.first .. my_emp_table.last loop
dbms_output.put_line(my_emp_table.lastname(i));
end loop;
end;
Variables in nested blocks:
declare
d_birth_date date;
begin
declare
d_birth_date date;
begin
...
Outer.d_birth_date:=to_Date(’03-NOV-2013’,’DD-MON-YYYY’);
end;

5. Anar Godjaev
http://anargodjaev.wordpress.com/
...
end;
EX:
<<outer>>-- label the outer block
Declare
n_sum_salnumber(10,2);
n_dept_nonumber not null := 60;
--n_employee_idemployees.employee_id%TYPE;
Begin
declare
n_sum_salnumber(10,2) := 1111;
begin
/*
select sum(salary) into outer.n_sum_sal
from employees
wheredepartment_id = n_dept_no;
*/
-- call to outer block variable
outer.n_sum_sal:= 2532.22;
end;
dbms_output.put_line('The outer sum salary is: ' ||
to_char(n_sum_sal));
/*
selecthire_date from employees
whereemployee_id = n_employee_id;
*/
end;