1、SQL常用語句+舉例相關表:Storenformatio n表Store_ namesalesdateLos An geles$1500Ja n-05-1999San Diego$250Ja n-07-1999Los An geles$300Ja n-08-1999Bost on$700Ja n-08-1999Geography 表Regi on_n ameStore _n ameEastBost onEastNew YorkWestLOS An gelesWestSan Diego1. dist inct:剔除重復記錄例: select distinet stroe_name from St

2、ore_information結果:Store_ nameLos An gelesSan DiegoBost on2. And / or:并且 / 或例：在表中選出所有 sales 高于$1000或是sales在$275及$500之間的記錄Select store_ name ,sales from Store_ in formati onWhere sales1000Or (sales275 and sales $1500結果:store_ namesum(sales)Los An geles$180011. Alias :別名，字段別名和表格別名語法：select 字段名AS字段別名fro

3、m 表名AS表別名 例：select store_name AS store from Storenformation AS S1結果12. 左連接/內部連接例：查找每一區域的 salesSelect , from Geography AS A2,Store_i nformation AS A1Where =Group byregi onsaleseast$700west$2050果:13. 外部連接:+店，這時我們要用外部連接Select ,sum from eography AS A1,Store_ in formatio n AS A2Where =(+)Group by14. Crea

4、t table:創建表Creat table custome(first_ name char(50),Lat_ name char(50),Birth_date date)15. Creat view :創建視圖Creat view V_customeAS select first_ name,last_ name from custome16. Creat index :創建索引Creat in dex idx_customeast_ name on custome(last_ name)17. Alter table:修改表加一個字段：Alter table custome add ge

5、nder char(2)刪除一個字段:Alter table customedrop gender改變字段名稱:Alter table customechange first_name f_name char(50)改變字段類型:Alter table customemodify first_ name char(30)18. Primary key: 主鍵，不能為空Alter table custome add primary key(sid)19. 外鍵：指向另一個表主鍵的字段Creat table users(ud int,U_n ame char(20)Primary key(u_id)Foreig n key( u_n ame) refere nces custome(sid)20. Truncate table 表名：清除表中數據21. Insert into:向表中插入記錄Insertintostroe_ in formati on(store_ name,sales,date)values(pi ny , $900 , ja n-10-1999 )22. Update:更新記錄Update stroe_ in formati onSet sales=$600And date