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oracle distinct
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distinctÕâ¸ö¹Ø¼ü×ÖÀ´¹ýÂ˵ô¶àÓàµÄÖØ¸´¼Ç¼ֻ±£ÁôÒ»Ìõ£¬µ«ÍùÍùÖ»Óà ËüÀ´·µ»Ø²»Öظ´¼Ç¼µÄÌõÊý£¬¶ø²»ÊÇÓÃËüÀ´·µ»Ø²»ÖؼǼµÄËùÓÐÖµ¡£ÆäÔ­ÒòÊÇdistinctÖ»ÓÐÓöþÖØÑ­»·²éѯÀ´½â¾ö£¬¶øÕâÑù¶ÔÓÚÒ»¸öÊý¾ÝÁ¿·Ç³£´óµÄÕ¾À´Ëµ£¬ÎÞÒÉÊÇ»áÖ±½ÓÓ°Ï쵽ЧÂʵġ£
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×Ö¶Î1     ×Ö¶Î2
   id        name
   1           a
   2           b
   3           c
   4           c
   5           b
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select distinct name from table
µÃµ½µÄ½á¹ûÊÇ:
 
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name
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   b
   c
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select distinct name, id from table
½á¹û»áÊÇ:
---------- 
id name
   1 a
   2 b
   3 c
   4 c
   5 b
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select id, distinct name from table
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select *, count(distinct name) from table group by name
½á¹û:
   id name count(distinct name)
   1 a 1
   2 b 1
   3 c 1
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