ä»åæ²è¼ã®å 容 SQLã§éè¨ãè¡ãã«ã¯ï¼ ãGROUP BYãå¥ã®å¶ç´ ååã®æå®ãASã ç¹å®ã®éè¨è¡ã®ã¿ã®è¡¨ç¤º SQLã§éè¨ãè¡ãã«ã¯ï¼ ä»åã¯ãSQLæã§ã®éè¨ã®æ¹æ³ï¼GROUP BYï¼ã説æãã¾ããååã¾ã§ã«èª¬æãããSELECTãæã§ã¯ããã¼ã¿ãåå¾ã表示ãããå ´åã表示ããããã¼ã¿ã¯å ã®ãã¼ã¿ã®ä¸é¨ããããã¯ãã¹ã¦ã§ãããä»å使ç¨ãããGROUP BYãå¥ã使ç¨ããã¨ãç¹å®ã®åããã¼ã«ããåè¨å¤ãå¹³åå¤ãªã©ã表示ãããçµæã¨ãªãã¾ããã¾ãã¯ãä¾1ã®SQLæãå®è¡ãã¦ã¿ã¾ããããåå説æããã¨ããããOrder Detailsããã¼ãã«ã®æå®ã« " "ï¼ ããã«ã»ã¯ãªã¼ãã¼ã·ã§ã³ï¼ã使ç¨ãã¦ãã¾ãã®ã§ã注æãã¦ãã ãããã
MySQL ï¼ã¾ããåãªã SQLï¼ã§ããã¼ã¿ãã¼ã¹ä¸ã®éè¤ã¬ã³ã¼ããé¤ãã¦æ¤ç´¢ããã«ã¯ distinct ã使ãã®ãå®ç³ã ãããã®éã«éè¤ã¬ã³ã¼ãã®ã¿æ½åºã»åå¾ãããå ´åã¯ã©ã®ããã«ãããããã®ã ããï¼çµè«ã¯ã以ä¸ã®ããã«ããã°ããã select * from ãã¼ãã«A where åA in (select åA from ãã¼ãã«A group by åA having count(*) > 1); éè¤é ç®ã®ãããã¼ã¿ãæ½åº ï¼æã㦠SQLï¼ ãéè¤ã¬ã³ã¼ããåå¾ããã ï¼My wonderful livingï¼
ãªãªã¼ã¹ãé害æ å ±ãªã©ã®ãµã¼ãã¹ã®ãç¥ãã
ææ°ã®äººæ°ã¨ã³ããªã¼ã®é ä¿¡
j次ã®ããã¯ãã¼ã¯
kåã®ããã¯ãã¼ã¯
lãã¨ã§èªã
eã³ã¡ã³ãä¸è¦§ãéã
oãã¼ã¸ãéã
{{#tags}}- {{label}}
{{/tags}}