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SQL Error Code 1054 Unknown Column

This is my request:

create table if not exists applications (
    idResearch int not null, 
    idProf char(10) not null,
    primary key (idResearch, idProf),
    foreign key (idResearch) references research(idResearch),
    foreign key (idProf) references professor(idProf)
);

and this is the table:

INSERT INTO `university`.`applications` (`idResearch`, `idProf`) VALUES ('10', '123456789');
INSERT INTO `university`.`applications` (`idResearch`, `idProf`) VALUES ('10', '432156789');
INSERT INTO `university`.`applications` (`idResearch`, `idProf`) VALUES ('10', '789654321');
INSERT INTO `university`.`applications` (`idResearch`, `idProf`) VALUES ('11', '876098432');
INSERT INTO `university`.`applications` (`idResearch`, `idProf`) VALUES ('11', '234567890');
INSERT INTO `university`.`applications` (`idResearch`, `idProf`) VALUES ('12', '432156789');
INSERT INTO `university`.`applications` (`idResearch`, `idProf`) VALUES ('12', '789654321');
INSERT INTO `university`.`applications` (`idResearch`, `idProf`) VALUES ('13', '876098432');
INSERT INTO `university`.`applications` (`idResearch`, `idProf`) VALUES ('14', '876098432');
INSERT INTO `university`.`applications` (`idResearch`, `idProf`) VALUES ('14', '987654321');
INSERT INTO `university`.`applications` (`idResearch`, `idProf`) VALUES ('15', '432156789');
INSERT INTO `university`.`applications` (`idResearch`, `idProf`) VALUES ('16', '123456789');
INSERT INTO `university`.`applications` (`idResearch`, `idProf`) VALUES ('16', '432156789');
INSERT INTO `university`.`applications` (`idResearch`, `idProf`) VALUES ('16', '789654321');
INSERT INTO `university`.`applications` (`idResearch`, `idProf`) VALUES ('17', '789654321');
INSERT INTO `university`.`applications` (`idResearch`, `idProf`) VALUES ('17', '432156789');

15:26:13 create a table if there are no applications (idResearch int not null, idProf char (10) not null, primary key (idResearch, idProf), foreign key (idResearch) links research (idResearch), foreign key (idProf) refer professor (idProf)) Error code: 1215. Unable to add foreign key constraint 0.109 sec

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2 answers

There is no syntax problem in your request, it could be a data problem.

Before you insert a query, check the following

  • There is a table 'research' and column 'idResearch'
  • There is a professor table and an idProf column.
  • ( ) idResearch, idProf .

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0

foreign key:

constraint FKResearch foreign key (idResearch) references research(idResearch),
constraint FKProfessor foreign key (idProf) references professor(idProf)

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, , , , , ( , ).

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