categories: computer science
Hello everyone,
Below you will find a video with a detailed explanation of the statements and keywords related to: mathematical functions and subqueries. It covers how they work, their time complexity, and their usefulness. Below you will also find ready-to-copy code in case you need it.
Query 1:
SELECT ROUND(Srednia^2, 3) AS KwadratSredniej,
ROUND(SQR(Srednia), 3) AS PierwiastekSredniej,
ROUND(ABS(SQR(Srednia) - Srednia^2) MOD Srednia, 3) AS ModuloKwadratPierwiastek
FROM srednia
WHERE ABS(DATEDIFF('d', DataP, DataK)) < 30;
Statements: SELECT, ROUND, AS, SQR, ABS, MOD, FROM, WHERE, DATEDIFF
Query 2:
SELECT Imie, Nazwisko
FROM uczniowie
WHERE IdUcznia =
(SELECT TOP 1 Id
FROM srednia
ORDER BY Srednia DESC);
Statements: SELECT, FROM, WHERE, TOP, ORDER BY, DESC
Query 3:
SELECT TOP 1 Imie, Nazwisko
FROM uczniowie
INNER JOIN srednia ON srednia.Id = uczniowie.IdUcznia
ORDER BY Srednia DESC;
Statements: SELECT, TOP, FROM, INNER JOIN, ON, ORDER BY, DESC
Query 4:
SELECT Imie, Nazwisko
FROM uczniowie
WHERE IdUcznia IN
(SELECT Id
FROM srednia
WHERE Srednia > 4.0);
Statements: SELECT, FROM, WHERE, IN
Query 5:
SELECT Imie, Nazwisko
FROM uczniowie
WHERE IdUcznia NOT IN
(SELECT Id
FROM srednia
WHERE Srednia > 4.0);
Statements: SELECT, FROM, WHERE, NOT IN
Query 6:
SELECT MAX(LEN(Nazwisko)) AS DlugoscNajdNazwiZ1A
FROM (SELECT Nazwisko
FROM uczniowie
WHERE klasa = '1A');
Statements: SELECT, MAX, LEN, AS, FROM
Video:
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