오라클(oracle)과 MS-SQL 함수, 쿼리 차이점

출처 : http://mt1716.egloos.com/10590565

쿼리 오라클9i MS-SQL2000 값 대체 DECODE ex) DECODE(컬럼명, 'A', 'OK', 'B', 'NO', 컬럼명) CASE WHEN (오라클도 있음) ex) CASE WHEN 컬럼명 = 'A' THEN 'OK' WHEN 컬럼명 = 'B' THEN 'NO' ELSE 컬럼명 END 문자열 자르기 SUBSTR ex) SUBSTR('ANSDDD', 1, 2) = 'AN' SUBSTRING ex) SUBSTRING('ANSDDD', 1,2) = 'AN' 시스템시간 SYSDATE GETDATE() 널값제어 NVL ex) NVL(컬럼명,0) => 컬럼값이 널이면 0으로 대체 isNULL ex) isNULL(컬럼명,0) => 컬럼값이 널이면 0으로 대체 형변환 TO_CHAR,TO_NUMBER ex) TO_CHAR(컬럼명) => 문자열 형태로 변환 CONVERT ex) CONVERT(VARCHAR,컬럼명) => 문자열 형태로 변환

차이점(MS-SQL 사용시 유의점)

1. MS-SQL2000은 재귀순환쿼리 (ORACLE 의 CONNECT BY) 구문이 없습니다..
MS-SQL2005에서는 지원된다고 합니다.
따라서 재귀순환이 필요할 경우 함수를 만들어 사용해야 합니다.
ex)
-------------------------------------------------------------------
CREATE FUNCTION fn_recursivemenu(@current as varchar(10))
RETURNS @Hierarchy table (
 item_idx [int] IDENTITY (1, 1) NOT NULL , item varchar(20), up_item varchar(20), lvl int
)
-- Recusrsive메뉴 구현
as
begin
 DECLARE @lvl int
 DECLARE @stack table (item varchar(20), up_item varchar(20), lvl int)
 
    INSERT INTO @stack VALUES (@current, null, 1)
    SELECT @lvl = 1
    WHILE @lvl > 0
       BEGIN
          IF EXISTS (SELECT * FROM @stack WHERE lvl = @lvl)
             BEGIN

                SELECT @current = item
                FROM @stack
                WHERE lvl = @lvl

                INSERT INTO @Hierarchy
                SELECT menu_id, up_menu_id, menu_level FROM SYS_MENU
                WHERE menu_id = @current

                DELETE FROM @stack
                WHERE lvl = @lvl
                   AND item = @current

                INSERT @stack
                SELECT menu_id, up_menu_id, @lvl + 1
                FROM SYS_MENU
                WHERE up_menu_id = @current
   ORDER BY menu_id desc

                IF @@ROWCOUNT > 0
                   SELECT @lvl = @lvl + 1

             END

          ELSE

             SELECT @lvl = @lvl - 1
 
       END
 
 RETURN
END
------------------------------------------------------------

2. MS-SQL 은 하위쿼리 테이블 쿼리시 꼭 alias 명을 명시적으로
부여해야 됩니다.
 ex) select * from (select * from table) --- 에러
      select * from (select * from table) a --- OK

3. MS-SQL2000 Rownum 매기는법(편법)
  : MS-SQL에서 순차적인 번호를 매기기 위해서는 IDENTITY를 컬럼에 부여해주는

    방법밖에 없습니다.
    꼭 순차적인 번호를 부여해야 하는 경우라면 아래예문같은 방법을 사용해서 구현

    할 수는 있습니다만 그다지 추천할 방법은 아닙니다.

ex)
-------------------------
SELECT 
  ((SELECT count(*) FROM [테이블명] b where b.키컬럼 <= a.키컬럼)+200700000) AS ROWNUM
FROM                                                     
  [테이블명] a 
ORDER BY 키컬럼
-------------------------
[결과]
200700001
200700002

 

 

Math Functions
Function	Oracle	SQL Server
Absolute value	ABS	ABS
Arc cosine	ACOS	ACOS
Arc sine	ASIN	ASIN
Arc tangent of n	ATAN	ATAN
Arc tangent of n and m	ATAN2	ATN2
Smallest integer >= value	CEIL	CEILING
Cosine	COS	COS
Hyperbolic cosine	COSH	COT
Exponential value	EXP	EXP
Round down to nearest integer	FLOOR	FLOOR
Natural logarithm	LN	LOG
Logarithm, any base	LOG(N)	N/A
Logarithm, base 10	LOG(10)	LOG10
Modulus (remainder)	MOD	USE MODULO (%) OPERATOR
Power	POWER	POWER
Random number	N/A	RAND
Round	ROUND	ROUND
Sign of number	SIGN	SIGN
Sine	SIN	SIN
Hyperbolic sine	SINH	N/A
Square root	SQRT	SQRT
Tangent	TAN	TAN
Hyperbolic tangent	TANH	N/A
Truncate	TRUNC	N/A
Highest number in list	GREATEST	N/A
Lowest number in list	LEAST	N/A
Convert number if NULL	NVL	ISNULL

 

String Functions
Function	Oracle	SQL Server
Convert character to ASCII	ASCII	ASCII
String concatenate	CONCAT	(expression! + expression!)
Convert ASCII to character	CHR	CHAR
Return starting point of character in character string (from left)	INSTR	CHARINDEX
Convert characters to lowercase	LOWER	LOWER
Convert characters to uppercase	UPPER	UPPER
Pad left side of character string	LPAD	N/A
Remove leading blank spaces	LTRIM	LTRIM
Remove trailing blank spaces	RTRIM	RTRIM
Starting point of pattern in character string	INSTR	PATINDEX
Repeat character string multiple times	RPAD	REPLICATE
Phonetic representation of character string	SOUNDEX	SOUNDEX
String of repeated spaces	RPAD	SPACE
Character data converted from numeric data	TO_CHAR	STR
Substring	SUBSTR	SUBSTRING
Replace characters	REPLACE	STUFF
Capitalize first letter of each word in string	INITCAP	N/A
Translate character string	TRANSLATE	N/A
Length of character string	LENGTH	DATALENGTH or LEN
Greatest character string in list	GREATEST	N/A
Least character string in list	LEAST	N/A
Convert string if NULL	NVL	ISNULL

 

Date Functions
Function	Oracle	SQL Server
Date addition	(use +)	DATEADD
Date subtraction	(use -)	DATEDIFF
Last day of month	LAST_DAY	N/A
Time zone conversion	NEW_TIME	N/A
First weekday after date	NEXT_DAY	N/A
Convert date to string	TO_CHAR	DATENAME
Convert date to number	TO_NUMBER(TO_CHAR())	DATEPART
Convert string to date	TO_DATE	CAST
Get current date and time	SYSDATE	GETDATE()

 

 

 

substr == substring
to_char == convert
--to_char(to_date(a.accept_da,'YYYY-MM-DD'), 'yyyy.mm.dd'),
 convert(varchar(10),cast(a.accept_da as smalldatetime),102),
 
-- to_char(a.dr_amt, '999,999,999,999,999'),
subString(convert(varchar, cast(a.dr_amt as money ),1),1,len(convert(varchar, cast(a.dr_amt as money ),1))-3),
subString(convert(varchar, cast(a.cr_amt as money ),1),1,len(convert(varchar, cast(a.cr_amt as money ),1))-3),

--TO_CHAR(last_day(DATEADD(month,substring('20050127',1,6) +  '01',-1)), 'YYYYMMDD')
dateadd(dd, -datepart(dd, cast('20050127' as smalldatetime)), dateadd(mm,1,cast('20050127' as smalldatetime)))

 

 

LPAD == replace

NVL == COALESCE

-- AND ROWNUM = 1
TOP 1

--   DECODE(dr_cr, 'D', SUM(currency_amt), 0) debt_amount,
--   DECODE(dr_cr, 'C', SUM(currency_amt), 0) credit_amount,
(case dr_cr when 'D' then SUM(currency_amt) else 0 end) debt_amount,
(case dr_cr when 'C' then SUM(currency_amt) else 0 end) credit_amount,

--select LPAD(' ',TO_NUMBER(s.accnt_gubun) * 4,' ') ||  s.accnt_detal_name from tb_erp_faccnt_cd s where s.accnt_cd = a.accnt_cd) accnt_detal_name ,
select  accnt_cd, (select right(space(cast(s.accnt_gubun as int) * 4)+s.accnt_gubun,cast(s.accnt_gubun as int) * 4)+  s.accnt_detal_name from tb_erp_faccnt_cd s where s.accnt_cd = a.accnt_cd) accnt_detal_name ,

 

--to_char(add_months(to_date('@@accept_da_fr','yyyymmdd'),-12),'yyyymmdd')
convert(varchar(8),dateadd(month,-12,cast('@@accept_da_fr' as datetime)),112)

 

 

 

오라클의 trunc 함수를 MS-SQL에서 구현하기...

 

MSSQL

select

cast(round(A,0,1) as decimal(10))

from [TABLE]

 

 

# ORACLE

select trunc(A) from [TABLE]

 

  제목 : 오라클의 trunc와 같은 기능을 하는것??  
create table AAA
(
 A float
)

insert AAA values (10.12345)
insert AAA values (10.445)

select round(A,2,1), cast(round(A,2,1) as decimal(10,2)) from AAA
10.119999999999999 10.12
10.44 10.44
 

to_date --> cast

 

오라클에서 to_date는 형을 데이터 형식으로 바꾸는 함수 인데

to_date(컬럼명, 'YYYYMMDD') 이렇게 써주어서 변환했는데 MS-SQL에서는 CAST를 쓴다.

CAST(컬럼명 as smalldatetime) 이렇게 데이터 타입으로 바꾼다.

 

그럼 CONVERT는 안될까? ㅡㅡ;;

방금해봤는데..되긴된다.. 쿠허허허허

CONVERT(smalldatetime, 컬럼명)