{"id":1172,"date":"2016-01-03T10:03:48","date_gmt":"2016-01-03T10:03:48","guid":{"rendered":"http:\/\/haisins.epac.to\/wordpress\/?p=1172"},"modified":"2016-01-03T10:03:48","modified_gmt":"2016-01-03T10:03:48","slug":"%ec%98%a4%eb%9d%bc%ed%81%b4-%ea%b7%b8%eb%a3%b9-%ed%95%a8%ec%88%98","status":"publish","type":"post","link":"http:\/\/haisins.synology.me\/wordpress\/?p=1172","title":{"rendered":"\uc624\ub77c\ud074 \uadf8\ub8f9 \ud568\uc218"},"content":{"rendered":"

# \uadf8\ub8f9\ud568\uc218 <\/SPAN><\/P>
\n

\uadf8\ub8f9 \ud568\uc218\ub780 \uc5ec\ub7ec \ud589 \ub610\ub294 \ud14c\uc774\ube14 \uc804\uccb4\uc758 \ud589\uc5d0 \ub300\ud574 \ud568\uc218\uac00 \uc801\uc6a9\ub418\uc5b4 \ud558\ub098\uc758 \uacb0\uacfc\uac12\uc744 \uac00\uc838\uc624\ub294  \ud568\uc218\ub97c \ub9d0\ud569\ub2c8\ub2e4..
 
GROUP BY\uc808\uc744 \uc774\uc6a9\ud558\uc5ec \uadf8\ub8f9 \ub2f9 \ud558\ub098\uc758 \uacb0\uacfc\uac00 \uc8fc\uc5b4\uc9c0\ub3c4\ub85d \uadf8\ub8f9\ud654 \ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4.
  <\/SPAN><\/P>
\n

HAVING\uc808\uc744 \uc0ac\uc6a9\ud558\uc5ec \uadf8\ub8f9 \ud568\uc218\ub97c \uac00\uc9c0\uace0 \uc870\uac74\ube44\uad50\ub97c \ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4. <\/p>\n

COUNT(*)\ub97c \uc81c\uc678\ud55c \ubaa8\ub4e0 \uadf8\ub8f9\ud568\uc218\ub294 NULL\uac12\uc744 \uace0\ub824\ud558\uc9c0 \uc54a\uc2b5\ub2c8\ub2e4. <\/p>\n

MIN, MAX \uadf8\ub8f9\ud568\uc218\ub294 \ubaa8\ub4e0 \uc790\ub8cc\ud615\uc5d0 \ub300\ud574\uc11c \uc0ac\uc6a9 \ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4.
  <\/SPAN><\/P>
\n

# \uadf8\ub8f9\ud568\uc218 \uc885\ub958 <\/SPAN><\/P>
\n

COUNT : COUNT \ud568\uc218\ub294 \uac80\uc0c9\ub41c \ud589\uc758 \uc218\ub97c \ubc18\ud658\ud569\ub2c8\ub2e4. <\/SPAN><\/P>
\n

 <\/P>
\n

SQL>SELECT COUNT(deptno) FROM DEPT ; <\/SPAN><\/P>
\n

   <\/P>
\n

COUNT(DEPTNO) <\/SPAN><\/P>
\n

————- <\/SPAN><\/P>
\n

4 ==> \uac80\uc0c9\ub41c \ud589\uc758 \ucd1d \uc218 4\uac1c\ub97c \ubc18\ud658\ud569\ub2c8\ub2e4. \uc989 4\uac1c\uc758 \ubd80\uc11c\uac00 \uc874\uc7ac\ud569\ub2c8\ub2e4. <\/SPAN><\/P>
\n

   <\/P>
\n

MAX : MAX \ud568\uc218\ub294 \uceec\ub7fc\uc911\uc758 \ucd5c\ub300\uac12\uc744 \ubc18\ud658\ud569\ub2c8\ub2e4. <\/SPAN><\/P>
\n

 <\/P>
\n

SQL>SELECT MAX(sal) salary FROM emp ; <\/SPAN><\/P>
\n

   <\/P>
\n

SALARY <\/SPAN><\/P>
\n

———- <\/SPAN><\/P>
\n

5000 ==> sal\uceec\ub7fc\uc911\uc5d0\uc11c \uc81c\uc77c \ud070\uac12\uc744 \ubc18\ud658\ud569\ub2c8\ub2e4. \uc989 \uac00\uc7a5 \ud070 \uae09\uc5ec\ub97c \ubc18\ud658\ud569\ub2c8\ub2e4. <\/SPAN><\/P>
\n

   <\/P>
\n

MIN : MIN \ud568\uc218\ub294 \uceec\ub7fc\uc911\uc758 \ucd5c\uc18c\uac12\uc744 \ubc18\ud658\ud569\ub2c8\ub2e4. <\/SPAN><\/P>
\n

 <\/P>
\n

SQL>SELECT MIN(sal) salary FROM emp ; <\/SPAN><\/P>
\n

SALARY
———-
800 ==> sal\uceec\ub7fc\uc911\uc5d0\uc11c \uac00\uc7a5 \uc791\uc740 \uac12 \ubc18\ud658\ud569\ub2c8\ub2e4. \uc989 \uac00\uc7a5 \uc801\uc740 \uae09\uc5ec\ub97c \ubc18\ud658\ud569\ub2c8\ub2e4 <\/SPAN><\/P>
\n

   <\/P>
\n

AVG : AVG \ud568\uc218\ub294 \ud3c9\uade0\uac12\uc744 \ubc18\ud658\ud569\ub2c8\ub2e4. <\/SPAN><\/P>
\n

 <\/P>
\n

SQL>SELECT ROUND(AVG(sal),1) salary FROM emp WHERE deptno = 30 <\/SPAN><\/P>
\n

SALARY <\/SPAN><\/P>
\n

———- <\/SPAN><\/P>
\n

1566.7 ==> 30\ubd80\uc11c \uc0ac\uc6d0\uc758 \ud3c9\uade0 \uae09\uc5ec\ub97c \uc18c\uc218\uc810 1\uc790\ub9ac \uc774\ud558\uc5d0\uc11c \ubc18\uc62c\ub9bc\ud574\uc11c \ubcf4\uc5ec\uc90d\ub2c8\ub2e4. <\/SPAN><\/P>
\n

SUM : SUM \ud568\uc218\ub294 \uac80\uc0c9\ub41c \uceec\ub7fc\uc758 \ud569\uc744 \ubc18\ud658\ud569\ub2c8\ub2e4. <\/SPAN><\/P>
\n

 <\/P>
\n

SQL>SELECT SUM(sal) salary FROM emp WHERE deptno = 30; <\/SPAN><\/P>
\n

SALARY <\/SPAN><\/P>
\n

———- <\/SPAN><\/P>
\n

9400 ==> 30\ubd80\uc11c \uc0ac\uc6d0\uc758 \uae09\uc5ec \ud569\uacc4\ub97c \ubcf4\uc5ec\uc90d\ub2c8\ub2e4. <\/SPAN><\/P>
\n

STDDEV : STDDEV \ud568\uc218\ub294 \ud45c\uc900\ud3b8\ucc28\ub97c \ubc18\ud658\ud569\ub2c8\ub2e4. <\/SPAN><\/P>
\n

 <\/P>
\n

SQL> SELECT ROUND(STDDEV(sal),3) salary FROM emp WHERE deptno = 30 ; <\/SPAN><\/P>
\n

SALARY <\/SPAN><\/P>
\n

———- <\/SPAN><\/P>
\n

668.331 ==> 30\ubd80\uc11c \uc0ac\uc6d0\uc758 \uae09\uc5ec \ud45c\uc900\ud3b8\ucc28\ub97c \ubc18\ud658\ud569\ub2c8\ub2e4. <\/SPAN><\/P>
\n

  <\/SPAN> <\/P><\/p>\n","protected":false},"excerpt":{"rendered":"

# \uadf8\ub8f9\ud568\uc218 \uadf8\ub8f9 \ud568\uc218\ub780 \uc5ec\ub7ec \ud589 \ub610\ub294 \ud14c\uc774\ube14 \uc804\uccb4\uc758 \ud589\uc5d0 \ub300\ud574 \ud568\uc218\uac00 \uc801\uc6a9\ub418\uc5b4 \ud558\ub098\uc758 \uacb0\uacfc\uac12\uc744 \uac00\uc838\uc624\ub294  \ud568\uc218\ub97c \ub9d0\ud569\ub2c8\ub2e4.. GROUP BY\uc808\uc744 \uc774\uc6a9\ud558\uc5ec \uadf8\ub8f9 \ub2f9 \ud558\ub098\uc758 \uacb0\uacfc\uac00 \uc8fc\uc5b4\uc9c0\ub3c4\ub85d \uadf8\ub8f9\ud654 \ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4.  HAVING\uc808\uc744 \uc0ac\uc6a9\ud558\uc5ec \uadf8\ub8f9 \ud568\uc218\ub97c \uac00\uc9c0\uace0 \uc870\uac74\ube44\uad50\ub97c \ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4. COUNT(*)\ub97c \uc81c\uc678\ud55c \ubaa8\ub4e0 \uadf8\ub8f9\ud568\uc218\ub294 NULL\uac12\uc744 \uace0\ub824\ud558\uc9c0 \uc54a\uc2b5\ub2c8\ub2e4. MIN, MAX \uadf8\ub8f9\ud568\uc218\ub294 \ubaa8\ub4e0 \uc790\ub8cc\ud615\uc5d0 \ub300\ud574\uc11c \uc0ac\uc6a9 \ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4.   […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_bbp_topic_count":0,"_bbp_reply_count":0,"_bbp_total_topic_count":0,"_bbp_total_reply_count":0,"_bbp_voice_count":0,"_bbp_anonymous_reply_count":0,"_bbp_topic_count_hidden":0,"_bbp_reply_count_hidden":0,"_bbp_forum_subforum_count":0,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"spay_email":""},"categories":[9],"tags":[661],"jetpack_featured_media_url":"","amp_enabled":true,"_links":{"self":[{"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/1172"}],"collection":[{"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1172"}],"version-history":[{"count":0,"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/1172\/revisions"}],"wp:attachment":[{"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1172"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1172"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/haisins.synology.me\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1172"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}