Неизвестный столбец SQL в предложении WHERE, даже если столбец вставлен

Question

Я убедился, что использую одинарные кавычки вместо двойных, но по какой-то причине он говорит, что гендерный столбец неизвестен.

Я пытался изменить оператор 'AND' на строчные,Я пытался использовать различные цитаты, и я также установил порядок, в котором значения были заданы в содержании и значениях таблицы.

CREATE DATABASE MYSQLEXERCISE5;
USE MYSQLEXERCISE5;
CREATE TABLE myemployees (
gender VARCHAR(255),
first_name VARCHAR(255),
last_name VARCHAR(255),
birth_place VARCHAR(255),
citizen_ship VARCHAR(255),
yearly_wage INT(7) NOT NULL,
age INT(3) NOT NULL,
hours_worked INT(5) NOT NULL,
years_employed INT(6) NOT NULL
);

INSERT INTO myemployees (gender, first_name, last_name, birth_place, citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('M', 'Filip', 'Lazarevic', 'Montenegro', 'Australia', 30000, 19, 8000, 4);
INSERT INTO myemployees (gender, first_name, last_name, birth_place, citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('M', 'Daniel', 'Craig', 'USA', 'England', 75000, 37, 26000, 13);
INSERT INTO myemployees (gender, first_name, last_name, birth_place, citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('M', 'John', 'Jovovich', 'Serbia', 'USA', 55000, 27, 8000, 4);
INSERT INTO myemployees (gender, first_name, last_name, birth_place, citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('M', 'Stefan', 'Stojic', 'Croatia', 'Croatia', 'Spain', 100000, 24, 12000, 6);
INSERT INTO myemployees (gender, first_name, last_name, birth_place, citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('M', 'David', 'Longbottom', 'Ireland', 'UK', 67000, 43, 10000, 5);
INSERT INTO myemployees (gender, first_name, last_name, birth_place, citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('M', 'Riley', 'Reynolds', 'Canada', 'Canada', 90000, 30, 20000, 10);
INSERT INTO myemployees (gender, first_name, last_name, birth_place, citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('F', 'Riley', 'Raymond', 'Iceland', 'Greenland', 22000, 19, 6000, 3);
INSERT INTO myemployees (gender, first_name, last_name, birth_place, citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('M', 'Jade', 'Michaels', 'Egypt', 'France', 100000, 55, 30000, 15);
INSERT INTO myemployees (gender, first_name, last_name, birth_place, citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('F', 'Jade', 'Smith', 'Syria', 'India', 10000, 50, 10000, 5);
INSERT INTO myemployees (gender, first_name, last_name, birth_place, citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('M', 'Sam', 'Wilson', 'Scotland', 'Ireland', 34000, 25, 4000, 2);
INSERT INTO myemployees (gender, first_name, last_name, birth_place, citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('F', 'Sam', 'Wade', 'Russia', 'Finland', 55000, 32, 8000, 4);

SELECT * FROM myemployees WHERE first_name = 'Sam' AND gender = 'M';
SELECT * FROM myemployees WHERE first_name = 'Jade' AND gender = 'F';

Я хочу, чтобы это показывало людей по имени Сэм, чей пол M илюди по имени Джейд, чей пол F

Answer 1

Сначала удалите свою таблицу из базы данных, а затем выполните этот запрос

`CREATE TABLE myemployees (
gender VARCHAR(255),
first_name VARCHAR(255),
last_name VARCHAR(255),
birth_place VARCHAR(255),
citizen_ship VARCHAR(255),
yearly_wage INT NOT NULL,
age INT NOT NULL,
hours_worked INT NOT NULL,
years_employed INT NOT NULL
);

INSERT INTO myemployees (gender, first_name, last_name, birth_place, 
citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('M', 'Filip', 'Lazarevic', 'Montenegro', 'Australia', 30000, 19, 
8000, 
4);
INSERT INTO myemployees (gender, first_name, last_name, birth_place, 
citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('M', 'Daniel', 'Craig', 'USA', 'England', 75000, 37, 26000, 13);
INSERT INTO myemployees (gender, first_name, last_name, birth_place, 
citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('M', 'John', 'Jovovich', 'Serbia', 'USA', 55000, 27, 8000, 4);
INSERT INTO myemployees (gender, first_name, last_name, birth_place, 
citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('M', 'Stefan', 'Stojic', 'Croatia','Spain', 100000, 24, 12000, 6);
INSERT INTO myemployees (gender, first_name, last_name, birth_place, 
citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('M', 'David', 'Longbottom', 'Ireland', 'UK', 67000, 43, 10000, 5);
INSERT INTO myemployees (gender, first_name, last_name, birth_place, 
citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('M', 'Riley', 'Reynolds', 'Canada', 'Canada', 90000, 30, 20000, 10);
INSERT INTO myemployees (gender, first_name, last_name, birth_place, 
citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('F', 'Riley', 'Raymond', 'Iceland', 'Greenland', 22000, 19, 6000, 3);
INSERT INTO myemployees (gender, first_name, last_name, birth_place, 
citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('M', 'Jade', 'Michaels', 'Egypt', 'France', 100000, 55, 30000, 15);
INSERT INTO myemployees (gender, first_name, last_name, birth_place, 
citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('F', 'Jade', 'Smith', 'Syria', 'India', 10000, 50, 10000, 5);
INSERT INTO myemployees (gender, first_name, last_name, birth_place, 
citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('M', 'Sam', 'Wilson', 'Scotland', 'Ireland', 34000, 25, 4000, 2);
INSERT INTO myemployees (gender, first_name, last_name, birth_place, 
citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('F', 'Sam', 'Wade', 'Russia', 'Finland', 55000, 32, 8000, 4);`

Надеюсь, это поможет вам. Видите, это ошибка для вас

Answer 2

Вы можете попробовать использовать IN

SELECT * 
FROM myemployees 
WHERE 
   first_name in ('Sam','Jade') AND gender in ('M' , 'F')

Answer 3

вы ошиблись при вставке данных в этот столбец, поэтому вы получили эту ошибку

INSERT INTO myemployees (gender, first_name, last_name, birth_place, citizen_ship, 
yearly_wage, age, hours_worked, years_employed)
VALUES ('M', 'Stefan', 'Stojic', 'Croatia', 'Spain', 100000,24, 24,  6);

в этой строке вы указали 10 значений столбца, но это должно быть 9, в противном случае ваш запрос работает нормально

SELECT * FROM myemployees WHERE first_name = 'Sam' AND gender = 'M';

output

gender  first_name  last_name   birth_place     citizen_ship    yearly_wage     age     hours_worked    years_employed
M   Sam     Wilson  Scotland    Ireland     34000   25  4000    2

SELECT * FROM myemployees WHERE first_name = 'Jade' AND gender = 'F';

output

gender  first_name  last_name   birth_place     citizen_ship    yearly_wage     age     hours_worked    years_employed
F   Jade    Smith   Syria   India   10000   50  10000   5

вот демонстрационная ссылка

, которую вы можете объединить с помощью union all

SELECT * FROM myemployees WHERE first_name = 'Sam' AND gender = 'M'
union all
SELECT * FROM myemployees WHERE first_name = 'Jade' AND gender = 'F'

вместо unoin all вы можете использовать in, который показывает @ fa06, или вы можете использовать OR, который показывает @ D-shish

Answer 4

Вы можете попробовать использовать or

Схема (MySQL v5.7)

CREATE TABLE myemployees (
gender VARCHAR(255),
first_name VARCHAR(255),
last_name VARCHAR(255),
birth_place VARCHAR(255),
citizen_ship VARCHAR(255),
yearly_wage INT(7) NOT NULL,
age INT(3) NOT NULL,
hours_worked INT(5) NOT NULL,
years_employed INT(6) NOT NULL
);

INSERT INTO myemployees (gender, first_name, last_name, birth_place, citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('M', 'Filip', 'Lazarevic', 'Montenegro', 'Australia', 30000, 19, 8000, 4);
INSERT INTO myemployees (gender, first_name, last_name, birth_place, citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('M', 'Daniel', 'Craig', 'USA', 'England', 75000, 37, 26000, 13);
INSERT INTO myemployees (gender, first_name, last_name, birth_place, citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('M', 'John', 'Jovovich', 'Serbia', 'USA', 55000, 27, 8000, 4);

INSERT INTO myemployees (gender, first_name, last_name, birth_place, citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('M', 'David', 'Longbottom', 'Ireland', 'UK', 67000, 43, 10000, 5);
INSERT INTO myemployees (gender, first_name, last_name, birth_place, citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('M', 'Riley', 'Reynolds', 'Canada', 'Canada', 90000, 30, 20000, 10);
INSERT INTO myemployees (gender, first_name, last_name, birth_place, citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('F', 'Riley', 'Raymond', 'Iceland', 'Greenland', 22000, 19, 6000, 3);
INSERT INTO myemployees (gender, first_name, last_name, birth_place, citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('M', 'Jade', 'Michaels', 'Egypt', 'France', 100000, 55, 30000, 15);
INSERT INTO myemployees (gender, first_name, last_name, birth_place, citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('F', 'Jade', 'Smith', 'Syria', 'India', 10000, 50, 10000, 5);
INSERT INTO myemployees (gender, first_name, last_name, birth_place, citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('M', 'Sam', 'Wilson', 'Scotland', 'Ireland', 34000, 25, 4000, 2);
INSERT INTO myemployees (gender, first_name, last_name, birth_place, citizen_ship, yearly_wage, age, hours_worked, years_employed)
VALUES ('F', 'Sam', 'Wade', 'Russia', 'Finland', 55000, 32, 8000, 4);

---

Запрос # 1

SELECT * 
FROM myemployees 
WHERE (first_name = 'Sam' AND gender = 'M') or (first_name = 'Jade' AND gender = 'F');

| gender | first_name | last_name | birth_place | citizen_ship | yearly_wage | age | hours_worked | years_employed |
| ------ | ---------- | --------- | ----------- | ------------ | ----------- | --- | ------------ | -------------- |
| F      | Jade       | Smith     | Syria       | India        | 10000       | 50  | 10000        | 5              |
| M      | Sam        | Wilson    | Scotland    | Ireland      | 34000       | 25  | 4000         | 2              |

---

Посмотреть на БД Fiddle