sql語句常用增刪改查
阿新 • • 發佈:2019-01-04
(本文是參考w3c中的sql教程內容,再結合其他相關材料整理的)
一、插入(複製)表資料
1、INSERT INTO 語句
(1)插入新的一行資料
[sql] view plain copy print?- INSERTINTO Persons VALUES ('Gates', 'Bill', 'Xuanwumen 10', 'Beijing');
INSERT INTO Persons VALUES ('Gates', 'Bill', 'Xuanwumen 10', 'Beijing');
(2)在指定的列中插入資料
[sql]
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print- INSERTINTO Persons (LastName, Address) VALUES ('Wilson', 'Champs-Elysees');
INSERT INTO Persons (LastName, Address) VALUES ('Wilson', 'Champs-Elysees');
2、SQL SELECT INTO 語句可用於建立表的備份復件
(1)在建表時複製所有資料:
[sql] view plain copy print?- createtable userinfo_new asselect * from userinfo;
create table userinfo_new as select * from userinfo;
(2)在建表時複製部分資料: [sql] view plain copy print?
- createtable userinfo_new1 asselect id,username from userinfo;
create table userinfo_new1 as select id,username from userinfo;
(3)在新增時複製所有資料: [sql] view plain copy print?
- insertinto userinfo_new select * from userinfo;
insert into userinfo_new select * from userinfo;
(4)在新增時複製部分資料: [sql] view plain copy print?
- insertinto userinfo_new(id,username) select id,username from userinfo;
insert into userinfo_new(id,username) select id,username from userinfo;
二、修改表資料
1、Update 語句
(1)無條件更新:
- update userinfo set userpwd='111',email='[email protected]';
update userinfo set userpwd='111',email='[email protected]';
(2)有條件更新:
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- update userinfo set userpwd='123456'where username='xxx';
update userinfo set userpwd='123456' where username='xxx';
三、刪除表資料
1、DELETE 語句
無條件刪除:
[sql] view plain copy print?- dalete from userinfo;
dalete from userinfo;
有條件刪除:
[sql]
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- deletefrom userinfo where username='yyy';
delete from userinfo where username='yyy';
四、查詢表資料
1、SELECT 語句
(1)查詢所有欄位:
[sql] view plain copy print?- select * from users;
select * from users;
(2)查詢指定欄位:
[sql]
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print?
- select username,salary from users;
select username,salary from users;
2、SELECT DISTINCT 語句
如需從 Company" 列中僅選取唯一不同的值,我們需要使用 SELECT DISTINCT 語句:
[sql] view plain copy print?- SELECTDISTINCT Company FROM Orders;
SELECT DISTINCT Company FROM Orders;
3、SQL where
選取居住在城市 "Beijing" 中的人,我們需要向 SELECT 語句新增 WHERE 子句:
- SELECT * FROM Persons WHERE City='Beijing';
SELECT * FROM Persons WHERE City='Beijing';
注意:SQL 使用單引號來環繞文字值(大部分資料庫系統也接受雙引號)。如果是數值,請不要使用引號。4、SQL AND & OR
(1)使用 AND 來顯示所有姓為 "Carter" 並且名為 "Thomas" 的人:
[sql] view plain copy print?- SELECT * FROM Persons WHERE FirstName='Thomas'AND LastName='Carter';
SELECT * FROM Persons WHERE FirstName='Thomas' AND LastName='Carter';
(2)使用 OR 來顯示所有姓為 "Carter" 或者名為 "Thomas" 的人:[sql] view plain copy print?
- SELECT * FROM Persons WHERE firstname='Thomas'OR lastname='Carter';
SELECT * FROM Persons WHERE firstname='Thomas' OR lastname='Carter';
5、ORDER BY 語句用於對結果集進行排序。(1)以字母順序顯示公司名稱:
[sql] view plain copy print?
- SELECT Company, OrderNumber FROM Orders ORDERBY Company;
SELECT Company, OrderNumber FROM Orders ORDER BY Company;
(2)以字母順序顯示公司名稱(Company),並以數字順序顯示順序號(OrderNumber):[sql] view plain copy print?
- SELECT Company, OrderNumber FROM Orders ORDERBY Company, OrderNumber;
SELECT Company, OrderNumber FROM Orders ORDER BY Company, OrderNumber;
(3)以逆字母順序顯示公司名稱:[sql] view plain copy print?
- SELECT Company, OrderNumber FROM Orders ORDERBY Company DESC;
SELECT Company, OrderNumber FROM Orders ORDER BY Company DESC;
(4)以逆字母順序顯示公司名稱,並以數字順序顯示順序號:[sql] view plain copy print?
- SELECT Company, OrderNumber FROM Orders ORDERBY Company DESC, OrderNumber ASC;
SELECT Company, OrderNumber FROM Orders ORDER BY Company DESC, OrderNumber ASC;
6、TOP 子句
SQL Server 的語法:
從"Persons" 表中選取頭兩條記錄:[sql] view plain copy print?
- SELECTTOP 2 * FROM Persons;
SELECT TOP 2 * FROM Persons;
從"Persons" 表中選取 50% 的記錄:
[sql] view plain copy print?- SELECTTOP 50 PERCENT * FROM Persons;
SELECT TOP 50 PERCENT * FROM Persons;
MySQL 語法:
從"Persons" 表中選取頭兩條記錄: [sql] view plain copy print?- SELECT * FROM Persons LIMIT 2;
SELECT * FROM Persons LIMIT 2;
Oracle 語法:
從"Persons" 表中選取頭兩條記錄:[sql] view plain copy print?
- SELECT * FROM Persons WHERE ROWNUM <= 2;
SELECT * FROM Persons WHERE ROWNUM <= 2;
7、LIKE 操作符、SQL 萬用字元(1)從"Persons" 表中選取居住在以 "N" 開始的城市裡的人:
[sql] view plain copy print?
- SELECT * FROM Persons WHERE City LIKE'N%';
SELECT * FROM Persons WHERE City LIKE 'N%';
(2)從"Persons" 表中選取居住在以 "g" 結尾的城市裡的人:[sql] view plain copy print?
- SELECT * FROM Persons WHERE City LIKE'%g';
SELECT * FROM Persons WHERE City LIKE '%g';
(3)從 "Persons" 表中選取居住在包含 "lon" 的城市裡的人:[sql] view plain copy print?
- SELECT * FROM Persons WHERE City LIKE '%lon% ;
SELECT * FROM Persons WHERE City LIKE '%lon% ;
(4)從 "Persons" 表中選取居住在不包含 "lon"
的城市裡的人:[sql] view plain copy print?
- SELECT * FROM Persons WHERE City NOTLIKE'%lon%';
SELECT * FROM Persons WHERE City NOT LIKE '%lon%';
(5)從"Persons" 表中選取名字的第一個字元之後是 "eorge" 的人:[sql] view plain copy print?
- SELECT * FROM Persons WHERE FirstName LIKE'_eorge';
SELECT * FROM Persons WHERE FirstName LIKE '_eorge';
(6)從"Persons" 表中選取的這條記錄的姓氏以 "C" 開頭,然後是一個任意字元,然後是 "r",然後是任意字元,然後是 "er":[sql] view plain copy print?
- SELECT * FROM Persons WHERE LastName LIKE'C_r_er';
SELECT * FROM Persons WHERE LastName LIKE 'C_r_er';
(7)從"Persons" 表中選取居住的城市以 "A" 或 "L" 或 "N" 開頭的人:[sql] view plain copy print?
- SELECT * FROM Persons WHERE City LIKE'[ALN]%';
SELECT * FROM Persons WHERE City LIKE '[ALN]%';
(8)從"Persons" 表中選取居住的城市不以 "A"
或 "L" 或 "N" 開頭的人:[sql] view plain copy print?
- SELECT * FROM Persons WHERE City LIKE'[!ALN]%';
SELECT * FROM Persons WHERE City LIKE '[!ALN]%';
8、IN 操作符從表中選取姓氏為 Adams 和 Carter 的人:
[sql] view plain copy print?
- SELECT * FROM Persons WHERE LastName IN ('Adams','Carter');
SELECT * FROM Persons WHERE LastName IN ('Adams','Carter');
9、BETWEEN 操作符以字母順序顯示介於 "Adams"(包括)和 "Carter"(不包括)之間的人:
[sql] view plain copy print?
- SELECT * FROM Persons WHERE LastName BETWEEN'Adams'AND'Carter';
SELECT * FROM Persons WHERE LastName BETWEEN 'Adams' AND 'Carter';
注意:不同的資料庫對 BETWEEN...AND 操作符的處理方式是有差異的。某些資料庫會列出介於 "Adams" 和 "Carter" 之間的人,但不包括 "Adams" 和 "Carter" ;某些資料庫會列出介於 "Adams" 和 "Carter" 之間幷包括 "Adams" 和 "Carter" 的人;而另一些資料庫會列出介於 "Adams" 和 "Carter" 之間的人,包括 "Adams" ,但不包括 "Carter" 。
所以,請檢查你的資料庫是如何處理 BETWEEN....AND 操作符的!
10、為列名稱和表名稱指定別名(Alias) (1)表的 SQL Alias 語法[sql] view plain copy print?
- SELECT po.OrderID, p.LastName, p.FirstName FROM Persons AS p, Product_Orders AS po WHERE p.LastName='Adams'AND p.FirstName='John';
SELECT po.OrderID, p.LastName, p.FirstName FROM Persons AS p, Product_Orders AS po WHERE p.LastName='Adams' AND p.FirstName='John';
(2)列的 SQL Alias 語法[sql] view plain copy print?
- SELECT LastName AS Family, FirstName ASNameFROM Persons;
SELECT LastName AS Family, FirstName AS Name FROM Persons;
10、Join(Inner Join)、Left Join(Left Outer Join)、Right Join(Right Outer Join)、Full Join(Full Outer Join)
"Persons" 表:
Id_P | LastName | FirstName | Address | City |
---|---|---|---|---|
1 | Adams | John | Oxford Street | London |
2 | Bush | George | Fifth Avenue | New York |
3 | Carter | Thomas | Changan Street | Beijing |
"Orders" 表:
Id_O | OrderNo | Id_P |
---|---|---|
1 | 77895 | 3 |
2 | 44678 | 3 |
3 | 22456 | 1 |
4 | 24562 | 1 |
5 | 34764 | 65 |
- SELECT Persons.LastName, Persons.FirstName, Orders.OrderNo FROM Persons, Orders WHERE Persons.Id_P = Orders.Id_P ;
SELECT Persons.LastName, Persons.FirstName, Orders.OrderNo FROM Persons, Orders WHERE Persons.Id_P = Orders.Id_P ;
用Join(Inner Join)查詢:INNER JOIN 關鍵字在表中存在至少一個匹配時返回行。如果 "Persons" 中的行在 "Orders" 中沒有匹配,就不會列出這些行。
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- SELECT Persons.LastName, Persons.FirstName, Orders.OrderNo FROM Persons INNERJOIN Orders ON Persons.Id_P = Orders.Id_P ORDERBY Persons.LastName;
SELECT Persons.LastName, Persons.FirstName, Orders.OrderNo FROM Persons INNER JOIN Orders ON Persons.Id_P = Orders.Id_P ORDER BY Persons.LastName;
LastName | FirstName | OrderNo |
---|---|---|
Adams | John | 22456 |
Adams | John | 24562 |
Carter | Thomas | 77895 |
Carter | Thomas | 44678 |
- SELECT Persons.LastName, Persons.FirstName, Orders.OrderNo FROM Persons LEFTJOIN Orders ON Persons.Id_P=Orders.Id_P ORDERBY Persons.LastName;
SELECT Persons.LastName, Persons.FirstName, Orders.OrderNo FROM Persons LEFT JOIN Orders ON Persons.Id_P=Orders.Id_P ORDER BY Persons.LastName;
LastName | FirstName | OrderNo |
---|---|---|
Adams | John | 22456 |
Adams | John | 24562 |
Carter | Thomas | 77895 |
Carter | Thomas | 44678 |
Bush | George |
- SELECT Persons.LastName, Persons.FirstName, Orders.OrderNo FROM Persons RIGHTJOIN Orders ON Persons.Id_P=Orders.Id_P ORDERBY Persons.LastName;
SELECT Persons.LastName, Persons.FirstName, Orders.OrderNo FROM Persons RIGHT JOIN Orders ON Persons.Id_P=Orders.Id_P ORDER BY Persons.LastName;
LastName | FirstName | OrderNo |
---|---|---|
Adams | John | 22456 |
Adams | John | 24562 |
Carter | Thomas | 77895 |
Carter | Thomas | 44678 |
34764 |
[sql] view plain copy print?
- SELECT Persons.LastName, Persons.FirstName, Orders.OrderNo FROM Persons FULL