Oracle SQL built-in functions

Single-record functions in SQL

1. ASCIIReturns the decimal number corresponding to the specified character;
SQL> select ASCII ('A') A, ASCII ('A') A, ASCII ('0') zero, ASCII ('') space from dual;

A A zero space
------------------------------------
65 97 48 32

2. CHRReturns the corresponding characters;
SQL> select CHR (54740) Zhao, CHR (65) chr65 from dual;

Zh C
---
Zhao

3. ConcatConnect two strings;
SQL> select Concat ('010-', '000000') |' to 23' Gao Qian competing phone number from dual;

Gao Qian's phone number
----------------
010-88888888 to 23

4. initcapReturns a string and converts the first letter of the string to uppercase;
SQL> select initcap ('Smith ') upp from dual;

UPP
-----
Smith

5. instr (C1, C2, I, j)Searches for a specified character in a string and returns the location where the specified character is found;
String searched by C1
String to be searched by C2
The start position of the I search. The default value is 1.
Where J appears. The default value is 1.
SQL> select instr ('oracle traning', 'A', 1, 2) instring from dual;

Instring
---------
9

6. LengthReturns the length of the string;
SQL> select name, length (name), ADDR, length (ADDR), Sal, length (to_char (SAL) from. nchar_tst;

Name Length (name) ADDR length (ADDR) Sal length (to_char (SAL ))
---------------------------------------------------------------------------
Gao Qian Jing 3 Beijing haiding District 6 9999.99 7

7. LowerReturns a string and lowercase letters of all characters.
SQL> select lower ('abbccdd') aabbccdd from dual;

Aabbccdd
--------
Aabbccdd

8. UpperReturns a string and upper-case all characters.
SQL> select upper ('abbccdd') Upper from dual;

Upper
--------
Aabbccdd

9. rpad and lpad (paste characters)
Pad the character on the right of the column
Lpad paste characters on the left of the column
SQL> select lpad (rpad ('gao', 10, '*'), 17, '*') from dual;

Lpad (rpad ('gao', 1
-----------------
* ******* Gao *******
If the character is not enough, use * to fill it up.

10. ltrim and rtrim
Ltrim deletes the string on the left
Rtrim deletes the string that appears on the right.
SQL> select ltrim (rtrim ('gao Qian jing', ''),'') from dual;

Ltrim (rtrim ('
-------------
Gao Qian Jing

11. substr (string, start, count)
Substring, starting from start, count
SQL> select substr ('123', 13088888888) from dual;

Substr ('
--------
08888888

12. Replace ('string', 's1', 's2 ')
String: the character or variable to be replaced.
String to be replaced by S1
String to be replaced by S2
SQL> select Replace ('He love you', 'hes', 'I') from dual;

Replace ('heloveyou', 'hes', 'I ')
------------------------------
I love you

13. soundexReturns a string with the same pronunciation as a given string.
SQL> Create Table Table1 (XM varchar (8 ));
SQL> insert into Table1 values ('weate ');
SQL> insert into Table1 values ('wether ');
SQL> insert into Table1 values ('gao ');

SQL> select XM from Table1 where soundex (XM) = soundex ('weate ');

XM
--------
Weather
Wether

14. Trim ('s 'from 'string ')
Leading
Trailing
If this parameter is not specified, the space character is used by default.

15. AbsReturns the absolute value of a specified value.
SQL> select ABS (100), ABS (-100) from dual;

ABS (100) ABS (-100)
------------------
100 100

16. ACOsReturns the arc cosine value.
SQL> select ACOs (-1) from dual;

ACOs (-1)
---------
3.1415927

17. AsinReturns the arcsin value.
SQL & gt; select asin (0.5) from dual;

Asin (0.5)
---------
. 52359878

18. atanReturns the arc tangent of a number.
SQL> select atan (1) from dual;

Atan (1)
---------
. 78539816

19. ceilReturns the smallest integer greater than or equal to the given number.
SQL> select Ceil (3.1415927) from dual;

Ceil (3.1415927)
---------------
4

20. CosReturns the cosine of a given number.
SQL> select cos (-3.1415927) from dual;

Cos (-1, 3.1415927)
---------------
-1

21. coshReturns the arc cosine of a number.
SQL> select cosh (20) from dual;

Cosh (20)
---------
242582598

22. ExpReturns the n root of the number E.
SQL> select exp (2), exp (1) from dual;

Exp (2) exp (1)
------------------
7.3890561 2.7182818

23. FloorReturns an integer to a given number.
SQL> select floor (2345.67) from dual;

Floor (2345.67)
--------------
2345

24. lnReturns the logarithm of a number.
SQL> select ln (1), Ln (2), Ln (2.7182818) from dual;

Ln (1) ln (2) ln (1, 2.7182818)
-------------------------------
0. 69314718. 99999999

25. Log (N1, N2)Returns the base N2 logarithm of N1.
SQL> Select log (2, 1), log (2, 4) from dual;

Log (2, 1) log (2, 4)
------------------

26. Mod (N1, N2)Returns the remainder of N1 divided by N2.
SQL> select Mod (10, 3), MOD (3, 3), MOD (2, 3) from dual;

MoD () mod)
---------------------------
1 0 2

27. PowerReturns the N2 root of N1.
SQL> select power (2, 10), power (3, 3) from dual;

Power (2, 10) power (3, 3)
---------------------
1024 27

28. Round and trunc
Round according to the specified precision
SQL> select round (55.5), round (-55.4), trunc (55.5), trunc (-55.5) from dual;

Round (55.5) round (-55.4) trunc (55.5) trunc (-55.5)
----------------------------------------------
56-55 55-55

29. SignReturns 1 if the number N is greater than 0,-1 if the value is less than 0, and 0 if the value is 0.
SQL> select sign (123), sign (-100), sign (0) from dual;

Sign (123) sign (-100) Sign (0)
----------------------------
1-1 0

30. SinReturns the sine of a number.
SQL> select sin (1.57079) from dual;

Sin (1.57079)
------------
1

31. SighReturns the hyperbolic sine value.
SQL> select sin (20), sinh (20) from dual;

Sin (20) sinh (20)
------------------
.. 91294525 242582598

32. SQRTReturns the root of number n.
SQL> select SQRT (64), SQRT (10) from dual;

SQRT (64) SQRT (10)
------------------
8 3.1622777

33. TanReturns the tangent of a number.
SQL> select Tan (20), Tan (10) from dual;

Tan (20) Tan (10)
------------------
2.2371609. 64836083

34. Tanh
Returns the hyperbolic tangent of number n.
SQL> select Tanh (20), Tan (20) from dual;

Tanh (20) Tan (20)
------------------
1 2.2371609

35. trunc
Truncate a number based on the specified precision
SQL> select trunc (124.1666,-2) trunc1, trunc (124.16666, 2) from dual;

Trunc1 trunc (124.16666, 2)
---------------------------
100 124.16

36. add_months
Add or subtract a month
SQL> select to_char (add_months (to_date ('000000', 'yyymmm'), 2), 'yyymmm') from dual;

To_cha
------
200002
SQL> select to_char (add_months (to_date ('000000', 'yyymmm'),-2), 'yyymmm') from dual;

To_cha
------
199910

37. last_day
Returns the last day of the date.
SQL> select to_char (sysdate, 'yyyy. Mm. dd'), to_char (sysdate) + 1, 'yyyy. Mm. dd') from dual;

To_char (SY to_char (S
--------------------
2004.05.09 2004.05.10
SQL> select last_day (sysdate) from dual;

Last_day (S
----------
September 31-04

38. months_between (date2, date1)
Given the month of the date2-date1
SQL> select months_between ('19-December-1999 ', '19-March-1999') mon_between from dual;

Mon_between
-----------
9
SQL> selectmonths_between (to_date ('192. 100', 'yyyy. Mm. dd'), to_date ('192. 100', 'yyyy. dd') mon_betw from dual;

Mon_betw
---------
-60

39. new_time (date, 'this', 'that ')
Returns the date and time in this time zone = Other time zone.
SQL> select to_char (sysdate, 'yyyy. Mm. dd hh24: MI: ss') bj_time, to_char (new_time
2 (sysdate, 'pdt ', 'gmt'), 'yyyy. Mm. dd hh24: MI: ss') los_angles from dual;

Bj_time los_angles
--------------------------------------
2004.05.09 11:05:32 2004.05.09 18:05:32

40. next_day (date, 'day ')
Returns the date of the week and the date of the next week after week X.
SQL> select next_day ('18-May-2001 ', 'Friday') next_day from dual;

Next_day
----------
25-5-01

41. sysdateUsed to obtain the current date of the system
SQL> select to_char (sysdate, 'dd-mm-yyyy Day') from dual;

To_char (sysdate ,'
-----------------
09-05-2004 Sunday
Trunc (date, FMT) truncates the date according to the given requirements. If FMT = 'mi ', it indicates that the minute is retained and the second is truncated.
SQL> select to_char (trunc (sysdate, 'hh'), 'yyyy. Mm. dd hh24: MI: ss') HH,
2 to_char (trunc (sysdate, 'mi'), 'yyyy. Mm. dd hh24: MI: ss') hhmm from dual;

HH hhmm
--------------------------------------
2004.05.09 11:00:00 2004.05.09 11:17:00

42. chartorowidConvert character data type to rowid type
SQL> select rowid, rowidtochar (rowid), ename from Scott. EMP;

Rowid rowidtochar (rowid) ename
----------------------------------------------
Aaaafkaacaaaaeqaaa Smith
Aaaafkaacaaaaeqaab Allen
Aaaafkaacaaaaeqaac ward
Aaaafkaacaaaaeqaad Jones

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