Question

我正在尝试创建一个查询，显示所有因罚款而没有驾驶执照的人的姓名和地址。（所以不要出现在驾驶执照表中）我怎样才能包括没有出现在桌子上的东西？

这是我的表格

CREATE TABLE offences (
oOffenceID VARCHAR (30),
oDescription VARCHAR (200),
oMaximumFine INT (10),
CONSTRAINT o_pk
PRIMARY KEY (oOffenceID)
);

CREATE TABLE drivers (
dPersonID VARCHAR (30),
dLicenseNumber INT (20),
dLicenseRemoved ENUM('yes','no'),
dExpiryDate DATE,
CONSTRAINT d_pk
PRIMARY KEY (dLicenseNumber),
CONSTRAINT d_fk
FOREIGN KEY (dPersonId)
REFERENCES People (pPersonID)
);

CREATE TABLE people (
pPersonID VARCHAR (30),
pName VARCHAR (30),
pAddress VARCHAR (50),
pNIN VARCHAR (30),
CONSTRAINT p_pk
PRIMARY KEY (pPersonID)
);

CREATE TABLE vehicle (
vOwnerID VARCHAR (30),
vColour VARCHAR (30),
vModel VARCHAR (30),
vMake VARCHAR (30),
vVehicleID VARCHAR (30),
CONSTRAINT v_pk
PRIMARY KEY (vVehicleID),
CONSTRAINT v_fk
FOREIGN KEY (vOwnerID)
REFERENCES People (pPersonID)
);

CREATE TABLE fines (
fFineID INT (30) AUTO_INCREMENT,
fVehicleID VARCHAR (30),
fPersonID VARCHAR (30),
fTime DATE,
fAmount INT (10),
fOfficerStatement VARCHAR (500),
fOffenceID VARCHAR (30),
CONSTRAINT f_pk
PRIMARY KEY (fFineID),
CONSTRAINT f_fk
FOREIGN KEY (fVehicleID)
REFERENCES vehicle (vVehicleID),
CONSTRAINT f_fk1
FOREIGN KEY (fPersonID)
REFERENCES people (pPersonID),
CONSTRAINT f_fk2
FOREIGN KEY (fOffenceID)
REFERENCES offences (oOffenceID)
);

到目前为止我已经

了

SELECT DISTINCT pName, pAddress
FROM people, fines, drivers
WHERE 
pPersonID <> dPersonID
AND
pPersonID = fPersonID
AND
fAmount > 0

但这并没有删除所有必要的数据。我们非常感谢您使用正确工具的任何帮助或指导。

Answer 1

使用LEFT JOIN并检查NULL值

示例：

SELECT *
FROM
table_A
LEFT JOIN table_B
ON table_A.id = table_b.a_id
WHERE table_B.a_id IS NULL

MYSQL设计查询问题

1 个答案: