2023年8月3日发(作者:)

sql常⽤语句整理(包括增删改查),适合⼩⽩使⽤⼀、插⼊(复制)表数据1、INSERT INTO 语句(1)插⼊新的⼀⾏数据[sql]

1. INSERT INTO Persons VALUES ('Gates', 'Bill', 'Xuanwumen 10', 'Beijing');

(2)在指定的列中插⼊数据[sql]

1. INSERT INTO Persons (LastName, Address) VALUES ('Wilson', 'Champs-Elysees');

2、

SQL SELECT INTO 语句可⽤于创建表的备份复件(1)在建表时复制所有数据:[sql]

1. create table userinfo_new as select * from userinfo;

(2)在建表时复制部分数据:[sql]

1. create table userinfo_new1 as select id,username from userinfo;

(3)在添加时复制所有数据:[sql]

1. insert into userinfo_new select * from userinfo;

(4)在添加时复制部分数据:[sql]

1. insert into userinfo_new(id,username) select id,username from userinfo;

⼆、修改表数据1、Update 语句(1)⽆条件更新:[sql]

1. update userinfo set userpwd='111',email='111@';

(2)有条件更新:[sql]

1. update userinfo set userpwd='123456' where username='xxx';

三、删除表数据1、DELETE 语句⽆条件删除:[sql]

1. dalete from userinfo;

有条件删除:[sql]

1. delete from userinfo where username='yyy';

四、查询表数据1、SELECT 语句(1)查询所有字段:[sql]

1. select * from users;

(2)查询指定字段:[sql]

1. select username,salary from users;

2、SELECT DISTINCT 语句如需从 Company" 列中仅选取唯⼀不同的值,我们需要使⽤ SELECT DISTINCT 语句:[sql]

1. SELECT DISTINCT Company FROM Orders;

3、SQL where选取居住在城市 "Beijing" 中的⼈,我们需要向 SELECT 语句添加 WHERE ⼦句:[sql]

1. SELECT * FROM Persons WHERE City='Beijing';

注意:

SQL 使⽤单引号来环绕

⽂本值

(⼤部分数据库系统也接受双引号)。如果是

数值

,请不要使⽤引号。4、SQL AND & OR(1)使⽤ AND 来显⽰所有姓为 "Carter" 并且名为 "Thomas" 的⼈:[sql]

1. SELECT * FROM Persons WHERE FirstName='Thomas' AND LastName='Carter'; (2)使⽤ OR 来显⽰所有姓为 "Carter" 或者名为 "Thomas" 的⼈:

[sql]

1. SELECT * FROM Persons WHERE firstname='Thomas' OR lastname='Carter';

5、

ORDER BY 语句⽤于对结果集进⾏排序。

(1)

以字母顺序显⽰公司名称:[sql]

1. SELECT Company, OrderNumber FROM Orders ORDER BY Company;

(2)

以字母顺序显⽰公司名称(Company),并以数字顺序显⽰顺序号(OrderNumber):[sql]

1. SELECT Company, OrderNumber FROM Orders ORDER BY Company, OrderNumber;

(3)

以逆字母顺序显⽰公司名称:[sql]

1. SELECT Company, OrderNumber FROM Orders ORDER BY Company DESC;

(4)

以逆字母顺序显⽰公司名称,并以数字顺序显⽰顺序号:[sql]

1. SELECT Company, OrderNumber FROM Orders ORDER BY Company DESC, OrderNumber ASC;

6、TOP ⼦句SQL Server 的语法:从"Persons" 表中选取头两条记录:[sql]

1. SELECT TOP 2 * FROM Persons;

从"Persons" 表中选取 50% 的记录:[sql]

1. SELECT TOP 50 PERCENT * FROM Persons;

MySQL 语法:从"Persons" 表中选取头两条记录:[sql]

1. SELECT * FROM Persons LIMIT 2;

Oracle 语法:从"Persons" 表中选取头两条记录:

[sql]

1. SELECT * FROM Persons WHERE ROWNUM <= 2;

7、LIKE 操作符、SQL 通配符

(1)从"Persons" 表中选取居住在以 "N" 开始的城市⾥的⼈: [sql]

1. SELECT * FROM Persons WHERE City LIKE 'N%';

(2) 从"Persons" 表中选取居住在以 "g" 结尾的城市⾥的⼈:[sql]

1. SELECT * FROM Persons WHERE City LIKE '%g';

(3) 从 "Persons" 表中选取居住在包含 "lon" 的城市⾥的⼈:

[sql]

1. SELECT * FROM Persons WHERE City LIKE '%lon% ;

(4) 从 "Persons" 表中选取居住在 不包含 "lon" 的城市⾥的⼈:

[sql]

1. SELECT * FROM Persons WHERE City NOT LIKE '%lon%';

(5) 从"Persons" 表中选取名字的第⼀个字符之后是 "eorge" 的⼈:

[sql]

1. SELECT * FROM Persons WHERE FirstName LIKE '_eorge';

(6) 从"Persons" 表中选取的这条记录的姓⽒以 "C" 开头,然后是⼀个任意字符,然后是 "r",然后是任意字符,然后是 "er":[sql]

1. SELECT * FROM Persons WHERE LastName LIKE 'C_r_er';

(7) 从"Persons" 表中选取居住的城市以 "A" 或 "L" 或 "N" 开头的⼈:

[sql]

1. SELECT * FROM Persons WHERE City LIKE '[ALN]%';

(8) 从"Persons" 表中选取居住的城市 不以 "A" 或 "L" 或 "N" 开头的⼈:

[sql]

1. SELECT * FROM Persons WHERE City LIKE '[!ALN]%';

8、IN 操作符

从表中选取姓⽒为 Adams 和 Carter 的⼈:

[sql]

1. SELECT * FROM Persons WHERE LastName IN ('Adams','Carter');

9、BETWEEN 操作符

以字母顺序显⽰介于 "Adams"(包括)和 "Carter"(不包括)之间的⼈:

[sql]

1. SELECT * FROM Persons WHERE LastName BETWEEN 'Adams' AND 'Carter';

注意:不同的数据库对 AND 操作符的处理⽅式是有差异的。某些数据库会列出介于 "Adams" 和 "Carter" 之间的⼈,但不包括"Adams" 和 "Carter" ;某些数据库会列出介于 "Adams" 和 "Carter" 之间并包括 "Adams" 和 "Carter" 的⼈;⽽另⼀些数据库会列出介于"Adams" 和 "Carter" 之间的⼈,包括 "Adams" ,但不包括 "Carter" 。所以,请检查你的数据库是如何处理 AND 操作符的!10、 为列名称和表名称指定别名(Alias)(1)表的 SQL Alias 语法[sql]

1. SELECT D, me, ame FROM Persons AS p, Product_Orders AS po WHERE me=(2)列的 SQL Alias 语法

[sql]

1. 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_P123LastNameAdamsBushCarterFirstNameJohnGeorgeThomasAddressOxford StreetFifth AvenueChangan StreetCityLondonNew YorkBeijing"Orders" 表:Id_O12345(1)Join⽤where 联表查询:[sql]

OrderNo7789544678224562456234764Id_P3311651. SELECT me, ame, o FROM Persons, Orders WHERE _P = _P ;

⽤Join(Inner Join)查询:INNER JOIN 关键字在表中存在⾄少⼀个匹配时返回⾏。如果 "Persons" 中的⾏在 "Orders" 中没有匹配,就不会列出这些⾏。[sql]

1. SELECT me, ame, o FROM Persons INNER JOIN Orders ON _P = _P

LastNameAdamsAdamsCarterCarterFirstNameJohnJohnThomasThomasOrderNo22456245627789544678(2)左外连接Left Join(Left Outer Join):LEFT JOIN 关键字会从左表 (Persons) 那⾥返回所有的⾏,即使在右表 (Orders) 中没有匹配的⾏。[sql]

1. SELECT me, ame, o FROM Persons LEFT JOIN Orders ON _P=_P

LastNameAdamsAdamsFirstNameJohnJohnOrderNo2245624562CarterCarterBushThomasThomasGeorge7789544678

(3)右外连接Right Join(Right Outer Join):RIGHT JOIN 关键字会从右表 (Orders) 那⾥返回所有的⾏,即使在左表 (Persons) 中没有匹配的⾏。[sql]

1. SELECT me, ame, o FROM Persons RIGHT JOIN Orders ON _P=_P

LastNameAdamsAdamsCarterCarter

FirstNameJohnJohnThomasThomas

OrderNo2245624562778954467834764(4)全连接Full Join(Full Outer Join):FULL JOIN 关键字会从左表 (Persons) 和右表 (Orders) 那⾥返回所有的⾏。如果 "Persons" 中的⾏在表 "Orders" 中没有匹配,或者如果 "Orders" 中的⾏在表 "Persons" 中没有匹配,这些⾏同样会列出。

[sql]

1. SELECT me, ame, o FROM Persons FULL JOIN Orders ON _P=_P

LastNameAdamsAdamsCarterCarterBush

FirstNameJohnJohnThomasThomasGeorge

OrderNo22456245627789544678

3476411、Union:UNION 操作符⽤于合并两个或多个 SELECT 语句的结果集。注意:UNION 内部的 SELECT 语句必须拥有相同数量的列。列也必须拥有相似的数据类型。同时,每条 SELECT 语句中的列的顺序必须相同。UNION 结果集中的列名总是等于 UNION 中第⼀个 SELECT 语句中的列名。Employees_China:E_ID01020304E_NameZhang, HuaWang, WeiCarter, ThomasYang, MingEmployees_USA:E_ID01020304E_NameAdams, JohnBush, GeorgeCarter, ThomasGates, Bill(1)UNION命令列出所有在中国和美国的不同的雇员名:[sql]

1. SELECT E_Name FROM Employees_China UNION SELECT E_Name FROM Employees_USA;

E_NameZhang, HuaWang, WeiCarter, ThomasYang, MingAdams, JohnBush, GeorgeGates, Bill(2)UNION ALL 命令列出在中国和美国的所有的雇员:

[sql]

1. SELECT E_Name FROM Employees_China UNION ALL SELECT E_Name FROM Employees_USA;

E_NameZhang, HuaWang, WeiCarter, ThomasYang, MingAdams, JohnBush, GeorgeCarter, ThomasGates, Bill12、SQL 的 NULL 值处理

(1) 选取在 "Address" 列中带有 NULL 值的记录:[sql]

1. SELECT LastName,FirstName,Address FROM Persons WHERE Address IS NULL;

(2) 选取在 "Address" 列中不带有 NULL 值的记录:[sql]

1. SELECT LastName,FirstName,Address FROM Persons WHERE Address IS NOT NULL;

13、SQL ISNULL()、NVL()、IFNULL() 和 COALESCE() 函数

P_Id123ProductNamecomputerprintertelephoneUnitPrice699365280UnitsInStock2536159UnitsOnOrder15

57在统计时,上表中 UnitsOnOrder字段值如果为null不利于计算,所以要⽤函数将null值当做0计算。SQL Server / MS Access:[sql]

1. SELECT ProductName,UnitPrice*(UnitsInStock+ISNULL(UnitsOnOrder,0)) FROM Products;

Oracle:[sql]

1. SELECT ProductName,UnitPrice*(UnitsInStock+NVL(UnitsOnOrder,0)) FROM Products;

MySQL:[sql]

1. SELECT ProductName,UnitPrice*(UnitsInStock+IFNULL(UnitsOnOrder,0)) FROM Products;

或[sql]

1. SELECT ProductName,UnitPrice*(UnitsInStock+COALESCE(UnitsOnOrder,0)) FROM Products;

2023年8月3日发(作者:)

sql常⽤语句整理(包括增删改查),适合⼩⽩使⽤⼀、插⼊(复制)表数据1、INSERT INTO 语句(1)插⼊新的⼀⾏数据[sql]

1. INSERT INTO Persons VALUES ('Gates', 'Bill', 'Xuanwumen 10', 'Beijing');

(2)在指定的列中插⼊数据[sql]

1. INSERT INTO Persons (LastName, Address) VALUES ('Wilson', 'Champs-Elysees');

2、

SQL SELECT INTO 语句可⽤于创建表的备份复件(1)在建表时复制所有数据:[sql]

1. create table userinfo_new as select * from userinfo;

(2)在建表时复制部分数据:[sql]

1. create table userinfo_new1 as select id,username from userinfo;

(3)在添加时复制所有数据:[sql]

1. insert into userinfo_new select * from userinfo;

(4)在添加时复制部分数据:[sql]

1. insert into userinfo_new(id,username) select id,username from userinfo;

⼆、修改表数据1、Update 语句(1)⽆条件更新:[sql]

1. update userinfo set userpwd='111',email='111@';

(2)有条件更新:[sql]

1. update userinfo set userpwd='123456' where username='xxx';

三、删除表数据1、DELETE 语句⽆条件删除:[sql]

1. dalete from userinfo;

有条件删除:[sql]

1. delete from userinfo where username='yyy';

四、查询表数据1、SELECT 语句(1)查询所有字段:[sql]

1. select * from users;

(2)查询指定字段:[sql]

1. select username,salary from users;

2、SELECT DISTINCT 语句如需从 Company" 列中仅选取唯⼀不同的值,我们需要使⽤ SELECT DISTINCT 语句:[sql]

1. SELECT DISTINCT Company FROM Orders;

3、SQL where选取居住在城市 "Beijing" 中的⼈,我们需要向 SELECT 语句添加 WHERE ⼦句:[sql]

1. SELECT * FROM Persons WHERE City='Beijing';

注意:

SQL 使⽤单引号来环绕

⽂本值

(⼤部分数据库系统也接受双引号)。如果是

数值

,请不要使⽤引号。4、SQL AND & OR(1)使⽤ AND 来显⽰所有姓为 "Carter" 并且名为 "Thomas" 的⼈:[sql]

1. SELECT * FROM Persons WHERE FirstName='Thomas' AND LastName='Carter'; (2)使⽤ OR 来显⽰所有姓为 "Carter" 或者名为 "Thomas" 的⼈:

[sql]

1. SELECT * FROM Persons WHERE firstname='Thomas' OR lastname='Carter';

5、

ORDER BY 语句⽤于对结果集进⾏排序。

(1)

以字母顺序显⽰公司名称:[sql]

1. SELECT Company, OrderNumber FROM Orders ORDER BY Company;

(2)

以字母顺序显⽰公司名称(Company),并以数字顺序显⽰顺序号(OrderNumber):[sql]

1. SELECT Company, OrderNumber FROM Orders ORDER BY Company, OrderNumber;

(3)

以逆字母顺序显⽰公司名称:[sql]

1. SELECT Company, OrderNumber FROM Orders ORDER BY Company DESC;

(4)

以逆字母顺序显⽰公司名称,并以数字顺序显⽰顺序号:[sql]

1. SELECT Company, OrderNumber FROM Orders ORDER BY Company DESC, OrderNumber ASC;

6、TOP ⼦句SQL Server 的语法:从"Persons" 表中选取头两条记录:[sql]

1. SELECT TOP 2 * FROM Persons;

从"Persons" 表中选取 50% 的记录:[sql]

1. SELECT TOP 50 PERCENT * FROM Persons;

MySQL 语法:从"Persons" 表中选取头两条记录:[sql]

1. SELECT * FROM Persons LIMIT 2;

Oracle 语法:从"Persons" 表中选取头两条记录:

[sql]

1. SELECT * FROM Persons WHERE ROWNUM <= 2;

7、LIKE 操作符、SQL 通配符

(1)从"Persons" 表中选取居住在以 "N" 开始的城市⾥的⼈: [sql]

1. SELECT * FROM Persons WHERE City LIKE 'N%';

(2) 从"Persons" 表中选取居住在以 "g" 结尾的城市⾥的⼈:[sql]

1. SELECT * FROM Persons WHERE City LIKE '%g';

(3) 从 "Persons" 表中选取居住在包含 "lon" 的城市⾥的⼈:

[sql]

1. SELECT * FROM Persons WHERE City LIKE '%lon% ;

(4) 从 "Persons" 表中选取居住在 不包含 "lon" 的城市⾥的⼈:

[sql]

1. SELECT * FROM Persons WHERE City NOT LIKE '%lon%';

(5) 从"Persons" 表中选取名字的第⼀个字符之后是 "eorge" 的⼈:

[sql]

1. SELECT * FROM Persons WHERE FirstName LIKE '_eorge';

(6) 从"Persons" 表中选取的这条记录的姓⽒以 "C" 开头,然后是⼀个任意字符,然后是 "r",然后是任意字符,然后是 "er":[sql]

1. SELECT * FROM Persons WHERE LastName LIKE 'C_r_er';

(7) 从"Persons" 表中选取居住的城市以 "A" 或 "L" 或 "N" 开头的⼈:

[sql]

1. SELECT * FROM Persons WHERE City LIKE '[ALN]%';

(8) 从"Persons" 表中选取居住的城市 不以 "A" 或 "L" 或 "N" 开头的⼈:

[sql]

1. SELECT * FROM Persons WHERE City LIKE '[!ALN]%';

8、IN 操作符

从表中选取姓⽒为 Adams 和 Carter 的⼈:

[sql]

1. SELECT * FROM Persons WHERE LastName IN ('Adams','Carter');

9、BETWEEN 操作符

以字母顺序显⽰介于 "Adams"(包括)和 "Carter"(不包括)之间的⼈:

[sql]

1. SELECT * FROM Persons WHERE LastName BETWEEN 'Adams' AND 'Carter';

注意:不同的数据库对 AND 操作符的处理⽅式是有差异的。某些数据库会列出介于 "Adams" 和 "Carter" 之间的⼈,但不包括"Adams" 和 "Carter" ;某些数据库会列出介于 "Adams" 和 "Carter" 之间并包括 "Adams" 和 "Carter" 的⼈;⽽另⼀些数据库会列出介于"Adams" 和 "Carter" 之间的⼈,包括 "Adams" ,但不包括 "Carter" 。所以,请检查你的数据库是如何处理 AND 操作符的!10、 为列名称和表名称指定别名(Alias)(1)表的 SQL Alias 语法[sql]

1. SELECT D, me, ame FROM Persons AS p, Product_Orders AS po WHERE me=(2)列的 SQL Alias 语法

[sql]

1. 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_P123LastNameAdamsBushCarterFirstNameJohnGeorgeThomasAddressOxford StreetFifth AvenueChangan StreetCityLondonNew YorkBeijing"Orders" 表:Id_O12345(1)Join⽤where 联表查询:[sql]

OrderNo7789544678224562456234764Id_P3311651. SELECT me, ame, o FROM Persons, Orders WHERE _P = _P ;

⽤Join(Inner Join)查询:INNER JOIN 关键字在表中存在⾄少⼀个匹配时返回⾏。如果 "Persons" 中的⾏在 "Orders" 中没有匹配,就不会列出这些⾏。[sql]

1. SELECT me, ame, o FROM Persons INNER JOIN Orders ON _P = _P

LastNameAdamsAdamsCarterCarterFirstNameJohnJohnThomasThomasOrderNo22456245627789544678(2)左外连接Left Join(Left Outer Join):LEFT JOIN 关键字会从左表 (Persons) 那⾥返回所有的⾏,即使在右表 (Orders) 中没有匹配的⾏。[sql]

1. SELECT me, ame, o FROM Persons LEFT JOIN Orders ON _P=_P

LastNameAdamsAdamsFirstNameJohnJohnOrderNo2245624562CarterCarterBushThomasThomasGeorge7789544678

(3)右外连接Right Join(Right Outer Join):RIGHT JOIN 关键字会从右表 (Orders) 那⾥返回所有的⾏,即使在左表 (Persons) 中没有匹配的⾏。[sql]

1. SELECT me, ame, o FROM Persons RIGHT JOIN Orders ON _P=_P

LastNameAdamsAdamsCarterCarter

FirstNameJohnJohnThomasThomas

OrderNo2245624562778954467834764(4)全连接Full Join(Full Outer Join):FULL JOIN 关键字会从左表 (Persons) 和右表 (Orders) 那⾥返回所有的⾏。如果 "Persons" 中的⾏在表 "Orders" 中没有匹配,或者如果 "Orders" 中的⾏在表 "Persons" 中没有匹配,这些⾏同样会列出。

[sql]

1. SELECT me, ame, o FROM Persons FULL JOIN Orders ON _P=_P

LastNameAdamsAdamsCarterCarterBush

FirstNameJohnJohnThomasThomasGeorge

OrderNo22456245627789544678

3476411、Union:UNION 操作符⽤于合并两个或多个 SELECT 语句的结果集。注意:UNION 内部的 SELECT 语句必须拥有相同数量的列。列也必须拥有相似的数据类型。同时,每条 SELECT 语句中的列的顺序必须相同。UNION 结果集中的列名总是等于 UNION 中第⼀个 SELECT 语句中的列名。Employees_China:E_ID01020304E_NameZhang, HuaWang, WeiCarter, ThomasYang, MingEmployees_USA:E_ID01020304E_NameAdams, JohnBush, GeorgeCarter, ThomasGates, Bill(1)UNION命令列出所有在中国和美国的不同的雇员名:[sql]

1. SELECT E_Name FROM Employees_China UNION SELECT E_Name FROM Employees_USA;

E_NameZhang, HuaWang, WeiCarter, ThomasYang, MingAdams, JohnBush, GeorgeGates, Bill(2)UNION ALL 命令列出在中国和美国的所有的雇员:

[sql]

1. SELECT E_Name FROM Employees_China UNION ALL SELECT E_Name FROM Employees_USA;

E_NameZhang, HuaWang, WeiCarter, ThomasYang, MingAdams, JohnBush, GeorgeCarter, ThomasGates, Bill12、SQL 的 NULL 值处理

(1) 选取在 "Address" 列中带有 NULL 值的记录:[sql]

1. SELECT LastName,FirstName,Address FROM Persons WHERE Address IS NULL;

(2) 选取在 "Address" 列中不带有 NULL 值的记录:[sql]

1. SELECT LastName,FirstName,Address FROM Persons WHERE Address IS NOT NULL;

13、SQL ISNULL()、NVL()、IFNULL() 和 COALESCE() 函数

P_Id123ProductNamecomputerprintertelephoneUnitPrice699365280UnitsInStock2536159UnitsOnOrder15

57在统计时,上表中 UnitsOnOrder字段值如果为null不利于计算,所以要⽤函数将null值当做0计算。SQL Server / MS Access:[sql]

1. SELECT ProductName,UnitPrice*(UnitsInStock+ISNULL(UnitsOnOrder,0)) FROM Products;

Oracle:[sql]

1. SELECT ProductName,UnitPrice*(UnitsInStock+NVL(UnitsOnOrder,0)) FROM Products;

MySQL:[sql]

1. SELECT ProductName,UnitPrice*(UnitsInStock+IFNULL(UnitsOnOrder,0)) FROM Products;

或[sql]

1. SELECT ProductName,UnitPrice*(UnitsInStock+COALESCE(UnitsOnOrder,0)) FROM Products;