《Mysql應用MySql數據庫中Select用法小結》要點:
本文介紹了Mysql應用MySql數據庫中Select用法小結,希望對您有用。如果有疑問,可以聯系我們。
MYSQL必讀一、條件篩選
MYSQL必讀1、數字篩選:sql = "Select * from [sheet1$] Where 銷售單價 > 100"
MYSQL必讀2、字符條件:sql = "Select * from [sheet1$] Where 物品名稱 ='擋泥板'"
MYSQL必讀3、日期條件:sql = "Select * from [sheet1$] Where 物品名稱 ='擋泥板'"
MYSQL必讀4、區間條件:sql = "Select * from [sheet1$] Where 出庫日期 between #2005-1-4# and #2005-1-10#"
MYSQL必讀5、多個條件:用and,OR連接
MYSQL必讀
'sql = "Select * from [sheet1$] Where 出庫日期 between #2005-1-4# and #2005-1-10# and 銷售單價>100"
MYSQL必讀6、模糊條件:%表示任意多個字符,_(下劃線)表示單個占位符
MYSQL必讀
'sql = "Select * from [sheet1$] Where 物品名稱 like '%扶手%'"
MYSQL必讀7、插入變量查詢:
MYSQL必讀
'sr = "擋泥板"
'sql = "Select * from [sheet1$] Where 物品名稱 ='" & sr & "'"
MYSQL必讀8、在字符串組里:
MYSQL必讀
'sql = "Select * from [sheet1$] Where 物品名稱 in('車衣','扶手箱')"
MYSQL必讀9、借用函數優化:
MYSQL必讀
'sql = "Select * from [sheet1$] Where left(物品代碼,3)='028'"
MYSQL必讀二、指定篩選
MYSQL必讀1、篩選全部字段:*表示全部字段
MYSQL必讀
'sql = "Select * from ChuKu"
MYSQL必讀2、篩選指定字段:在from前面列出要顯示的所有字段,如果要跳過的用""""
MYSQL必讀
'sql = "Select """",出庫日期,"""",物品代碼,"""",規格,單位 from ChuKu"
MYSQL必讀3、篩選不重復的:Distinct 字段名 篩選不重復的記錄
MYSQL必讀
'sql = "Select Distinct """",物品代碼 from ChuKu"
MYSQL必讀4、按百分比篩選:Top N percent 可以顯示前百分之N的記錄
MYSQL必讀
'sql = "Select top 30 Percent * from ChuKu"
MYSQL必讀'對篩選的字段用函數進行進一步的處理和格式化
MYSQL必讀
'sql = "Select ID,Format(出庫日期,""yyyy-mm-dd"") from ChuKu"
MYSQL必讀5、排序:Desc降序,Asc升序
MYSQL必讀
'sql = "Select * from ChuKu Order by 出庫日期 asc,銷售單價 desc"
'sql = "Select Top 10 * from ChuKu Order by 出庫日期 asc,銷售單價 desc" '篩選銷售數量前10()
MYSQL必讀三、分組顯示
MYSQL必讀Group by 可以配合函數進行分組求和,分組求最大值等.
MYSQL必讀
'sql = "Select """","""",物品代碼,"""","""","""",sum(出庫數量) from ChuKu group by 物品代碼" ' 跳過的用""""
MYSQL必讀按條件顯示分組記錄
MYSQL必讀
'sql = "Select """","""",物品代碼,"""","""","""",sum(出庫數量) from ChuKu group by 物品代碼 HAVING sum(出庫數量)>=3"
MYSQL必讀以上所述是小編給大家介紹的MySql數據庫中Select用法小結,希望對大家有所贊助,如果大家有任何疑問請給我留言,小編會及時回復大家的.在此也非常感謝大家對維易PHP網站的支持!
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