CREATE TABLE students ( code numeric(5,

Скачать презентацию CREATE TABLE students (   code numeric(5, Скачать презентацию CREATE TABLE students ( code numeric(5,

join.ppt

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Описание презентации CREATE TABLE students ( code numeric(5, по слайдам

  CREATE TABLE students (  code numeric(5, 0) PRIMARY KEY , fio character(30) NOT CREATE TABLE students ( code numeric(5, 0) PRIMARY KEY , fio character(30) NOT NULL, ) CREATE TABLE subjects ( code numeric(5, 0) PRIMARY KEY , name character(30) NOT NULL, ) CREATE TABLE grades ( code_stud numeric(5, 0 ) REFERENCES students (code) , code_ subj numeric(5, 0) REFERENCES subjects (code) , grade numeric(2, 0), )

  SELECT * FROM students INNER JOIN grades on TRUE Декартово произведение SELECT * FROM students INNER JOIN grades on TRUE Декартово произведение

  Внутреннее соединение SELECT * FROM students INNER JOIN grades ON students. code=grades. code_stud SELECT Внутреннее соединение SELECT * FROM students INNER JOIN grades ON students. code=grades. code_stud SELECT students. fio, grades. code_subj, grades. grade FROM students INNER JOIN grades ON students. code=grades. code_stud

  Декартово произведение SELECT * FROM subjects INNER JOIN grades ON true Декартово произведение SELECT * FROM subjects INNER JOIN grades ON true

  Внутреннее соединение SELECT * FROM subjects INNER JOIN grades ON subjects. code=grades. code_subj SELECT Внутреннее соединение SELECT * FROM subjects INNER JOIN grades ON subjects. code=grades. code_subj SELECT subjects. name, grades. code_stud, grades. grade FROM subjects INNER JOIN grades ON subjects. code=grades. code_subj

  Левое внешнее соединение SELECT students. fio, grades. code_subj, grades. grade FROM students LEFT OUTER Левое внешнее соединение SELECT students. fio, grades. code_subj, grades. grade FROM students LEFT OUTER JOIN grades ON students. code=grades. code_stud SELECT subjects. name, grades. code_stud, grades. grade FROM subjects LEFT OUTER JOIN grades ON subjects. code=grades. code_subj

  Правое внешнее соединение SELECT grades. code_subj, grades. grade, students. fio FROM grades RIGHT OUTER Правое внешнее соединение SELECT grades. code_subj, grades. grade, students. fio FROM grades RIGHT OUTER JOIN students ON grades. code_stud=students. code SELECT grades. code_stud, grades. grade, subjects. name FROM grades RIGHT OUTER JOIN subjects ON grades. code_subj=subjects. code

  Соединение трех таблиц SELECT students. fio, subjects. name, grades. grade FROM (students INNER JOIN Соединение трех таблиц SELECT students. fio, subjects. name, grades. grade FROM (students INNER JOIN grades ON students. code=grades. code_stud) INNER JOIN subjects ON grades. code_subj=subjects. code

  Использование псевдонимов,  фильтра WHERE SELECT st. fio, su. name, g. grade FROM (students Использование псевдонимов, фильтра WHERE SELECT st. fio, su. name, g. grade FROM (students as st INNER JOIN grades as g ON st. code=g. code_stud) INNER JOIN subjects as su ON g. code_subj=su. code WHERE g. grade>