개발자인생

WITH T AS (

SELECT  2500 AS COL1 FROM DUAL UNION ALL

SELECT  NULL AS COL1 FROM DUAL UNION ALL

SELECT  1000 AS COL1 FROM DUAL UNION ALL

SELECT  23   AS COL1 FROM DUAL UNION ALL

SELECT  NULL AS COL1 FROM DUAL

)

SELECT  * FROM T

ORDER BY COL1

  23

1000

2500

NULL

NULL

SELECT  * FROM T

ORDER BY COL1 NULLS FIRST

NULL

NULL

23

1000

2500

WITH T(TYPE, NAME, CODE) AS

(

SELECT '과일', '사과', '0' FROM dual

UNION ALL SELECT '과일', '레몬', '1' FROM dual

UNION ALL SELECT '과일', '포도', '2' FROM dual

UNION ALL SELECT '과일', '참외', '3' FROM dual

UNION ALL SELECT '채소', '오이', '0' FROM dual

UNION ALL SELECT '채소', '당근', '1' FROM dual

UNION ALL SELECT '채소', '호박', '2' FROM dual

)

SELECT type

     , SUBSTR(XMLAGG(XMLELEMENT(X, ',', NAME) ORDER BY CODE).EXTRACT('//text()'), 2) NAME_9I

     , WM_CONCAT(NAME) NAME_10G

     , LISTAGG(NAME, ',') WITHIN GROUP(ORDER BY CODE) NAME_11G

  FROM t

 GROUP BY type

 ORDER BY type

;

SELECT type

     , group_concat(name ORDER BY code) name_MySQL

  FROM t

 GROUP BY type

 ORDER BY type

SELECT type

     , STUFF((SELECT ',' + name

                FROM t

               WHERE type = a.type

               ORDER BY code

                 FOR XML PATH('')

              ), 1, 1, '') name_MSSQL

  FROM t a

 GROUP BY type

 ORDER BY type

>압축하기

#gzip 파일명

>압축풀기

#gzip 파일명.gz

>압축하고 원본파일 덮어쓰기

#gzip -f 파일명

>도움말보기

#gzip -h

usage: gzip [-cdfhlLnNrtvV19] [-S suffix] [file ...]

 -c --stdout      write on standard output, keep original files unchanged

 -d --decompress  decompress

 -f --force       force overwrite of output file and compress links

 -h --help        give this help

 -l --list        list compressed file contents

 -L --license     display software license

 -n --no-name     do not save or restore the original name and time stamp

 -N --name        save or restore the original name and time stamp

 -q --quiet       suppress all warnings

 -r --recursive   operate recursively on directories

 -S .suf  --suffix .suf     use suffix .suf on compressed files

 -t --test        test compressed file integrity

 -v --verbose     verbose mode

 -V --version     display version number

 -1 --fast        compress faster

 -9 --best        compress better

# locale

LANG=

LC_CTYPE="C"

LC_COLLATE="C"

LC_MONETARY="C"

LC_NUMERIC="C"

LC_TIME="C"

LC_MESSAGES="C"

LC_ALL=

# locale -a  | grep ko

ko_KR.eucKR

ko_KR.utf8

# export LANG=ko_KR.eucKR

# locale

LANG=ko_KR.eucKR

LC_CTYPE="ko_KR.eucKR"

LC_COLLATE="ko_KR.eucKR"

LC_MONETARY="ko_KR.eucKR"

LC_NUMERIC="ko_KR.eucKR"

LC_TIME="ko_KR.eucKR"

LC_MESSAGES="ko_KR.eucKR"

LC_ALL=

WW : 해당해의 1일부터 7일단위로 끊어서 주차를 생성

IW   : 날짜 해당한 주가 하루라도 다음해인 경우에는 그해의 첫주가 됨.

W : 해당월의 주차를 구함

UPDATE TAB1 A 

SET     COL1 = ( SELECT COL2 

                         FROM TAB2

                         WHERE   KEY = A.KEY );

UPDATE  /*+ BYPASS_UJVC  */

(

    SELECT  A.COL1   COL1

                , B.COL2   COL2

    FROM   TAB1 A

               , TAB2 B

    WHERE   A.KEY = B.KEY

)

SET COL1 = COL2

UPDATE  TAB1

SET        COL1 = B.COL2

FROM     TAB1 A INNER JOIN TAB2 B ON A.KEY = B.KEY

WITH T AS (

SELECT '324324'    COL1, 'ASDDD' COL2 FROM DUAL UNION ALL

SELECT 'AB234C'    COL1, 'AG_%%D' COL2 FROM DUAL UNION ALL

SELECT 'A3424B'    COL1, 'AS_DFD' COL2 FROM DUAL UNION ALL

SELECT 'AB234C'    COL1, 'AS_DDD' COL2 FROM DUAL UNION ALL

SELECT 'A3211C'    COL1, 'AS_DAZ' COL2 FROM DUAL UNION ALL

SELECT 'AB111C'    COL1, 'AG_D%F' COL2 FROM DUAL

)

SELECT * FROM T

WHERE COL1 LIKE 'AB%'

AB234C AG_%%D

AB234C AS_DDD

AB111C AG_D%F

SELECT * FROM T

WHERE COL1 LIKE '%4C'

AB234C AG_%%D

AB234C AS_DDD

SELECT * FROM T

WHERE WHERE COL1 LIKE '_B%'

AB234C AG_%%D

AB234C AS_DDD

AB111C AG_D%F

SELECT * FROM T

WHERE COL2 LIKE 'AG\_%' ESCAPE '\'

AB234C AG_%%D

AB111C AG_D%F

import java.awt.AWTException;

import java.awt.Robot;

import java.text.SimpleDateFormat;

import java.util.Date;

public class TimeDelayTest {

    public static void main(String arg[]) {

        SimpleDateFormat dayTime = new SimpleDateFormat("yyyy-mm-dd hh:mm:ss");

        long start = System.currentTimeMillis() ; 

        System.out.println("start=" + dayTime.format(new Date(start)));

        //5초 지연

        DelayTime(5);

        long end = System.currentTimeMillis(); 

        System.out.println("end  =" + dayTime.format(new Date(end)));

        System.out.println((end-start)/1000 +"초지연");

    }

    public static void DelayTime(int delaySec) {

        Robot robot = null;

        try {

            robot = new Robot();

        } catch (AWTException e) {

        }

        robot.delay(delaySec * 1000);

    }

}

start=2014-50-18 04:50:17

end  =2014-50-18 04:50:22

5초지연

SELECT  TRUNC(SYSDATE,'MONTH') FROM DUAL

UNION ALL

SELECT  TRUNC(SYSDATE,'MONTH')-1 FROM DUAL

UNION ALL

SELECT NEXT_DAY((TRUNC(SYSDATE,'MONTH')-1),'월') FROM DUAL

2014/03/01 00:00:00

2014/02/28 00:00:00

2014/03/03 00:00:00