MYSQL

left join 

SELECT `tbl_cours_info`.crs_nom as cours,
 concat(`tbl_professeur`.`prof_nom`," ",`tbl_professeur`.`prof_prenom`)as prof,
 `tbl_emploi_du_temps`.`empl_jours` as jours,
 `tbl_emploi_du_temps`.`empl_heures_begin` as tbegin,
 `tbl_emploi_du_temps`.`empl_heures_end` as tend
FROM `tbl_emploi_du_temps`
LEFT JOIN `tbl_cours_info` ON `tbl_emploi_du_temps`.`empl_cours_id` = `tbl_cours_info`.`crs_id`
LEFT JOIN `tbl_professeur` ON `tbl_emploi_du_temps`.`empl_prof_id`= `tbl_professeur`.`prof_id`
ORDER BY `tbl_emploi_du_temps`.`empl_jours` ASC

 

code citation sql

{-codecitation class="brush:sql" width="500px"} {-/codecitation}

 

mysql add foreign key 外键 

 -- -------------------------------------------------------------------------------------------
ALTER TALBE tbl_choix_examen
ADD PRIMARY KEY (choix_examen_id);
-- -------------------------------------------------------------------------------------------
ALTER TABLE `tbl_choix_examen` ADD PRIMARY KEY ( `choix_examen_id` ) 
-- -------------------------------------------------------------------------------------------
ALTER TABLE `ilci`.`tbl_choix_examen` ADD PRIMARY KEY ( `choix_examen_id` ) 
ALTER TABLE `tbl_choix_examen` CHANGE `choix_examen_id` `choix_examen_id` INT( 10 ) NOT NULL AUTO_INCREMENT 
-- -------------------------------------------------------------------------------------------
ALTER `ilci`.`tbl_choix_examen`
 ADD [CONSTRAINT [symbol]] FOREIGN KEY
 [index_name] (index_col_name, ...)
 REFERENCES tbl_name (index_col_name,...)
 [ON DELETE reference_option]
 [ON UPDATE reference_option]
-- -------------------------------------------------------------------------------------------
alter table `ilci`.`tbl_choix_examen` add foreign key(choix_examen_stu_id) references tbl_student(stu_id);
-- -------------------------------------------------------------------------------------------
alter table `ilci`.`tbl_choix_examen` add foreign key(choix_examen_emploi_id) references tbl_emploi_du_temps(empl_id);
-- -------------------------------------------------------------------------------------------
alter table `ilci`.`tbl_choix_examen_temps` add foreign key(emploi_du_temps_id) references tbl_emploi_du_temps(empl_id);
-- -------------------------------------------------------------------------------------------

 

   

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