Java od zera do developera

ER Diagrams Intro

Wyzwalacz (ang. trigger) – procedura wykonywana automatycznie jako reakcja na pewne zdarzenia w tabeli bazy danych . Wyzwalacze mogą ograniczać dostęp do pewnych danych, rejestrować zmiany danych lub nadzorować modyfikacje danych Trigger - Video -explained  CREATE TABLE trigger_test( message VARCHAR (100) ); DELIMITER $$ CREATE       TRIGGER my_trigger BEFORE INSERT       ON employee       FOR EACH ROW BEGIN           INSERT INTO trigger_test VALUES ('added new employee');       END $$ DELIMITER; Before anything new item will be added to employee table than insert into trigger value "Added new employee"  DELIMITER change ; into $$ because ; need to be use in TRIGGER what cause end of function DELIMITER $$ CREATE     TRIGGER my_trigger1 BEFORE INSERT      ON employee     FOR EACH ROW BEGIN       ...

SELECT * FROM branch; CREATE TABLE table_name ( column1 datatype, column2 datatype, column3 datatype, .... ); Typy danych w kolumnach Text data types: VARCHAR (40) - string z ograniczoną liczbą znaków TEXT - string BLOB - Binary Larg Objects - 65000 bytes of data ENUM('X','Y','Z') - list of values in order we enter them SET - values are ENUM up to 64 list items    Number data types: INT (size) - integer FLOAT(size,d) - small number with floating decimal point, d - decimal point DOUBLE(size,d) large number with floating decimal point Date data types: DATE() - YYYY-MM-DD TIMESTAMP() TIME() SQL Keywords: ADD - add column ALTER - add delete modify columns in table or change data types of column in table CREATE - create database, table, index, view, procedure CREATE DATABASE CREATE TABLE CREATE INDEX CREATE VIES DELETE - delete rows from table DESC - sort results descending order DROP - delet...