SQL語句去掉重復記錄,獲取重復記錄實例代碼

sql語句去掉重復記錄,獲取重復記錄?
查詢一個表中有效去掉重復的記錄,userid為自增長主鍵,roleid為重復字段

SELECT?MIN(UserID)?AS?UserID,?RoleID?FROM?tmpTable?GROUP?BY?RoleID?    SELECT?RoleID?FROM?tmpTable?GROUP?BY?RoleID?HAVING?(COUNT(*)?>?1)?    SELECT?DISTINCT?*?FROM?tmpTable

sql語句查詢?sql?server?access?數(shù)據(jù)庫里的所有表名,字段名2007年02月01日?星期四?下午?04:21SQL?SERVER?
查看所有表名:

select???name???from???sysobjects???where???type='U'

查詢表的所有字段名:

Select?name?from?syscolumns?Where?ID=OBJECT_ID('表名')?    select?*?from?information_schema.tables?  select?*?from?information_schema.views?  select?*?from?information_schema.columns

ACCESS
查看所有表名:

select???name???from???MSysObjects???where???type=1???and???flags=0

?MSysObjects是系統(tǒng)查詢,默認情況是隱藏的。通過工具、選項、查詢、顯示、系統(tǒng)對象可以使之顯示出來

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