Oracle 11g SQL
Version of implementation Oracle SQL of programming language SQLA stable major release of Oracle.
Examples:
Hello, World!  SQL (5):
‘Hello, World!’ string is selected from builtin table dual
which is used for queries which don’t need data from real tables.
select 'Hello, World!'
from dual;
Factorial  SQL (6):
Pure SQL doesn’t support loops, recursions or userdefined functions. This example shows one possible workaround which uses

pseudocolumn
level
to construct a pseudotable containing numbers 1 through 16, 
aggregate function
sum
which allows to sum the elements of a set 
and math functions
exp
andln
to replace multiplication (required to calculate the factorial) with addition (provided by SQL).
Note that 0! will not be present in the return, since trying to calculate ln(0) produces an exception.
select t2.n  '! = '  round(exp(sum(ln(t1.n))))
from
( select level n
from dual
connect by level <= 16) t1,
( select level n
from dual
connect by level <= 16) t2
where t1.n<=t2.n
group by t2.n
order by t2.n
Fibonacci numbers  SQL (13):
Pure SQL doesn’t support loops, recursions or userdefined functions. Besides, concatenating fields from multiple rows of a table or a subquery is not a standard aggregate function. This example uses:

Binet’s formula and math functions
round
,power
andsqrt
to calculate nth Fibonacci number;  pseudocolumn level to construct a pseudotable t1 containing numbers 1 through 16;

builtin function
SYS_CONNECT_BY_PATH
to concatenate the resulting numbers in ascending order.
SELECT REPLACE(MAX(SYS_CONNECT_BY_PATH(fib', ', '/')),'/','')'...' fiblist
FROM (
SELECT n, fib, ROW_NUMBER()
OVER (ORDER BY n) r
FROM (select n, round((power((1+sqrt(5))*0.5, n)power((1sqrt(5))*0.5, n))/sqrt(5)) fib
from (select level n
from dual
connect by level <= 16) t1) t2
)
START WITH r=1
CONNECT BY PRIOR r = r1;
Factorial  SQL (43):
This example shows the use of model
clause, available since Oracle 10g. It allows arraylike processing of query rows. Each row has two columns — iteration number (stored in n
) and its factorial (stored in f
).
select n  '! = '  f factorial
from dual
model
return all rows
dimension by ( 0 d )
measures ( 0 f, 1 n )
rules iterate (17)
( f[iteration_number] = decode(iteration_number, 0, 1, f[iteration_number1]*iteration_number),
n[iteration_number] = iteration_number
);
Fibonacci numbers  SQL (45):
This example shows the use of model
clause, available since Oracle 10g. It allows arraylike processing of query rows. Each row has two columns — Fibonacci number itself (stored in f) and concatenation of all Fibonacci numbers less than or equal to the current Fibonacci number (stored in s). Iterative aggregation of Fibonacci numbers in the same query that they were generated is easier than aggregating them separately.
select max(s)  ', ...'
from
(select s
from dual
model
return all rows
dimension by ( 0 d )
measures ( cast(' ' as varchar2(200)) s, 0 f)
rules iterate (16)
( f[iteration_number] = decode(iteration_number, 0, 1, 1, 1, f[iteration_number1] + f[iteration_number2]),
s[iteration_number] = decode(iteration_number, 0, to_char(f[iteration_number]), s[iteration_number1]  ', '  to_char(f[iteration_number]))
)
);
Hello, World!  SQL (89):
This example accomplishes the task by means of anonymous PL/SQL block, which uses standard package dbms_output
to print the message to standard output.
begin
dbms_output.put_line('Hello, World!');
end;
Factorial  SQL (90):
This example calculates factorials iteratively by means of PL/SQL.
declare
n number := 0;
f number := 1;
begin
while (n<=16)
loop
dbms_output.put_line(n  '! = '  f);
n := n+1;
f := f*n;
end loop;
end;
Fibonacci numbers  SQL (91):
This example implements iterative definition of Fibonacci numbers by means of PL/SQL. Already calculated numbers are stored in varray
, PL/SQL analogue of array in other languages.
declare
type vector is varray(16) of number;
fib vector := vector();
i number;
s varchar2(100);
begin
fib.extend(16);
fib(1) := 1;
fib(2) := 1;
s := fib(1)  ', '  fib(2)  ', ';
for i in 3..16 loop
fib(i) := fib(i1) + fib(i2);
s := s  fib(i)  ', ';
end loop;
dbms_output.put_line(s  '...');
end;
Quadratic equation  SQL (171):
This example was tested in SQL*Plus and TOAD.
Pure SQL allows to input values at runtime in the form of substitution variables. To define a substitution variable, use its name (in this case A, B and C) with an ampersand &
before it each time you need to reference it. When the query needs to be executed, you will receive a prompt to enter the values of the variables. Each reference to such variable will be replaced with its value, and the resulting query will be executed.
There are several ways to input the values for substitution variables. In this example first reference to each variable has double ampersand &&
before its name. This way the value of the variable has to be entered only once, and all following references will be replaced with the same value (using single ampersand in SQL*Plus asks to enter the value for each reference to the same variable). PL/SQL Developer requires that all variables have single &
before their names, otherwise ORA01008 “Not all variables bound” exception will be raised.
Note that the references are substituted with the values “as is”, so negative values of coefficients have to be entered in brackets.
First line of the example sets the character for decimal separator which is used when the numbers are converted into strings.
The query itself is composed of four different queries. Each query returns a string containing the result of calculations for one case of quadratic equation, and returns nothing for three other cases. The results of each query are united to produce the final result.
alter session set NLS_NUMERIC_CHARACTERS='. ';
select 'Not a quadratic equation.' ans
from dual
where &&A = 0
union
select 'x = '  to_char(&&B/2/&A)
from dual
where &A != 0 and &B*&B4*&A*&&C = 0
union
select 'x1 = '  to_char((&B+sqrt(&B*&B4*&A*&C))/2/&A)  ', x2 = '  to_char(&Bsqrt(&B*&B4*&A*&C))/2/&A
from dual
where &A != 0 and &B*&B4*&A*&C > 0
union
select 'x1 = ('  to_char(&B/2/&A)  ','  to_char(sqrt(&B*&B+4*&A*&C)/2/&A)  '), ' 
'x2 = ('  to_char(&B/2/&A)  ','  to_char(sqrt(&B*&B+4*&A*&C)/2/&A)  ')'
from dual
where &A != 0 and &B*&B4*&A*&C < 0;
CamelCase  SQL (283):
This example uses Oracle SQL regular expressions. First use of regexp_replace
replaces all digits with spaces — this is necessary for further initcap
usage (this function treats digits as parts of the words and doesn’t capitalize following letters). Next, initcap
converts all words to lowercase with first letter capitalized. Finally, second use of regexp_replace
removes all punctuation and spaces from the string.
&TEXT is substitution variable, which allows to input different strings without rewriting the select statement.
select regexp_replace(initcap(regexp_replace('&TEXT', '[[:digit:]]', ' ')), '([[:punct:]  [:blank:]])', '')
from dual
CamelCase  SQL (427):
This example uses Oracle regular expressions combined with PL/SQL. regex_substr
returns a substring of text
that is occurrence
‘s match to the given regular expression.
declare
text varchar2(100) := '&user_input';
word varchar2(100);
camelcase varchar2(100);
occurrence number := 1;
begin
loop
word := regexp_substr(text, '[[:alpha:]]+', 1, occurrence);
exit when word is null;
camelcase := camelcase  initcap(word);
occurrence := occurrence + 1;
end loop;
dbms_output.put_line(camelcase);
end;
Quadratic equation  SQL (428):
declare
A number := '&A';
B number := '&B';
C number := '&C';
D number := B * B  4 * A * C;
begin
if A = 0 then
dbms_output.put_line('Not a quadratic equation.');
return;
end if;
if D = 0 then
dbms_output.put_line('x = '  to_char(B/2/A));
elsif D > 0 then
dbms_output.put_line('x1 = '  to_char((Bsqrt(D))/2/A));
dbms_output.put_line('x2 = '  to_char((B+sqrt(D))/2/A));
else
dbms_output.put_line('x1 = ('  to_char(B/2/A)  ', '  to_char(sqrt(D)/2/A)  ')');
dbms_output.put_line('x2 = ('  to_char(B/2/A)  ', '  to_char(sqrt(D)/2/A)  ')');
end if;
end;
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