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ÕâÒ»Ò³µÄÄ¿µÄÊÇÌṩһ¸ö¼ò½àµÄ SQL Óï·¨×öΪ¶ÁÕ߲ο¼Ö®Óá£ÎÒÃǽ¨ÒéÄúÏÖÔھͰ´ Control-D ½«±¾Ò³¼ÓÈëÄúµÄ¡ºÎÒµÄ×î°®¡»¡£
Select
SELECT "À¸Î»" from "±í¸ñÃû"
Distinct
SELECT DISTINCT "À¸Î»"
from "±í¸ñÃû"
Where
SELECT "À¸Î»"
from "±í¸ñÃû"
WHERE "condition"
And/Or
SELECT "À¸Î»"
from "±í¸ñÃû"
WHERE "¼òµ¥Ìõ¼þ"
{[AND|OR] "¼òµ¥Ìõ¼þ"}+
In
SELECT "À¸Î»"
from "±í¸ñÃû"
WHERE "À¸Î»" IN ('Öµ1', 'Öµ2', ...)
Between
SELECT "À¸Î»"
from "±í¸ñÃû"
WHERE "À¸Î»" BETWEEN 'Öµ1' AND 'Öµ2'
Like
SELECT "À¸Î»"
from "±í¸ñÃû"
WHERE "À¸Î»" LIKE {ģʽ}
Order By
SELECT "À¸Î»"
from "±í¸ñÃû"
[WHERE "Ìõ¼þ"]
ORDER BY "À¸Î»" [ASC, DESC]
Count
SELECT COUNT("À¸Î»")
from "±í¸ñÃû"
Group By
SELECT "À¸Î»1", SUM("À¸Î»2")
from "±í¸ñÃû"
GROUP BY "À¸Î»1"
Having
SELECT "À¸Î»1", SUM("À¸Î»2")
from "±í¸ñÃû"
GROUP BY "À¸Î»1"
HAVING (À¸Î»)
Create Table
CREATE TABLE "±í¸ñÃû"
("À¸Î» 1" "À¸Î» 1 ×ÊÁÏÖÖÀà",
"À¸Î» 2" "À¸Î» 2 ×ÊÁÏÖÖÀà",
... )
Drop Table
DROP TABLE "±í¸ñÃû"
Truncate Table
TRUNCATE TABLE "±í¸ñÃû"
Insert Into
INSERT INTO "±í¸ñÃû" ("À¸Î»1", "À¸Î»2", ...)
VALUES ("Öµ1", "Öµ2", ...)
Update
UPDATE "±í¸ñÃû"
SET "À¸Î»1" = [ÐÂÖµ]
WHERE {Ìõ¼þ}
Delete from
DELETE from "±í¸ñÃû"
WHERE {Ìõ¼þ}


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SQL ±í¸ñÁ¬½ÓµÄÓ÷¨

ÏÖÔÚÎÒÃǽéÉÜÁ¬½Ó(join)µÄ¸ÅÄî¡£ÒªÁ˽âÁ¬½Ó£¬ÎÒÃÇÐèÒªÓõ½Ðí¶àÎÒÃÇ֮ǰÒѽéÉܹýµÄÖ¸Áî¡£ ÎÒÃÇÏȼÙÉèÎÒÃÇÓÐÒÔϵÄÁ½¸ö±í¸ñ£¬
Store_Information ±í¸ñ
store_name
Sales
Date
Los Angeles
$1500
Jan-05-1999
San Diego
$250
Jan-07-1999
Los Angeles
$300
Jan-08-1999
Boston
$700
Jan-08-199 ......

SQL CONCATENATEµÄÓ÷¨

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MySQL: CONCAT()
Oracle: CONCAT(), ||
SQL Server: +
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SQL SUBSTRINGµÄÓ÷¨

SQL ÖÐµÄ substring º¯ÊýÊÇÓÃÀ´×¥³öÒ»¸öÀ¸Î»×ÊÁÏÖÐµÄÆäÖÐÒ»²¿·Ö¡£Õâ¸öº¯ÊýµÄÃû³ÆÔÚ²»Í¬µÄ×ÊÁÏ¿âÖв»ÍêȫһÑù£º
MySQL: SUBSTR(), SUBSTRING()
Oracle: SUBSTR()
SQL Server: SUBSTRING()
×î³£Óõ½µÄ·½Ê½ÈçÏ (ÔÚÕâÀïÎÒÃÇÓÃSUBSTR()ΪÀý)£º
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SQL CREATE INDEXµÄÓ÷¨

Ë÷Òý (Index) ¿ÉÒÔ°ïÖúÎÒÃÇ´Ó±í¸ñÖпìËÙµØÕÒµ½ÐèÒªµÄ×ÊÁÏ¡£¾ÙÀýÀ´Ëµ£¬¼ÙÉèÎÒÃÇÒªÔÚÒ»±¾Ô°ÒÕÊéÖÐÕÒÈçºÎÖÖÖ²ÇཷµÄѶϢ¡£ÈôÕâ±¾ÊéûÓÐË÷ÒýµÄ»°£¬ÄÇÎÒÃÇÊDZØÐëÒª´ÓÍ·¿ªÊ¼¶Á£¬Ö±µ½ÎÒÃÇÕÒµ½ÓйØÖÖÖ±ÇཷµÄµØ·½ÎªÖ¹¡£ÈôÕâ±¾ÊéÓÐË÷ÒýµÄ»°£¬ÎÒÃǾͿÉÒÔÏÈÈ¥Ë÷ÒýÕÒ³öÖÖÖ²ÇཷµÄ×ÊѶÊÇÔÚÄÄÒ»Ò³£¬È»ºóÖ±½Óµ½ÄÇһҳȥÔĶÁ¡£ºÜÃ÷ÏԵأ¬ÔËÓ ......

SQL Ö÷¼üµÄÓ÷¨

Ö÷¼ü (Primary Key) ÖеÄÿһ±Ê×ÊÁ϶¼ÊDZí¸ñÖеÄΨһֵ¡£»»ÑÔÖ®£¬ËüÊÇÓÃÀ´¶ÀÒ»ÎÞ¶þµØÈ·ÈÏÒ»¸ö±í¸ñÖеÄÿһÐÐ×ÊÁÏ¡£Ö÷¼ü¿ÉÒÔÊÇÔ­±¾×ÊÁÏÄÚµÄÒ»¸öÀ¸Î»£¬»òÊÇÒ»¸öÈËÔìÀ¸Î» (ÓëÔ­±¾×ÊÁÏûÓйØÏµµÄÀ¸Î»)¡£Ö÷¼ü¿ÉÒÔ°üº¬Ò»»ò¶à¸öÀ¸Î»¡£µ±Ö÷¼ü°üº¬¶à¸öÀ¸Î»Ê±£¬³ÆÎª×éºÏ¼ü (Composite Key)¡£
Ö÷¼ü¿ÉÒÔÔÚ½¨ÖÃбí¸ñʱÉ趨 (ÔËÓà CREA ......
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