Znacenja nekih rezervisanih reci (The meanings of some reserved words)

Rezervisane reci:

• NOT NULL
• AUTO_INCREMENT
• PRIMARY KEY
• UNSIGNED

NOT NULL - taj atribut mora imati vrednost u svim redovima u tabeli. Ako ta opcija nije navedena, polje moze ostati prazno (NULL).

AUTO_INCREMENT - odnosi se na celobrojne kolone. MySQL ce ako prilikom unosenja redova u tabelu ostaviti prazno, austomatski generisati vrednost koja je jednistvena u koloni. Ta vrednost bice za jedan veca od postojece maksimalne vrednosti u koloni.

U tabeli moze da postoji samo jedna kolona definisana kao AUTO_INCREMENT. Takve kolone moraju biti indeksirane.

PRIMARY KEY - iza imena kolone kaze da je ta kolona primarni kljuc tabele. Vrednosti u toj koloni moraju biti jednistvene, a MySQL ce kolonu automatski indeksirati.

Reserved words:

NOT NULL
AUTO_INCREMENT
PRIMARY KEY
UNSIGNED
NOT NULL - this attribute must have a value in all rows in the table. If this option is not specified, the field can be left blank (NULL).

AUTO_INCREMENT - refers to the integer column. MySQL will if while entering the rows of the table left blank, automatically generate value which is unique in the column. This value will be greater for 1 than the current maximum value in the column.
IN the table can be only one column defined as AUTO_INCREMENT. Such columns must be indexed.


PRIMARY KEY - after the name of the column says that column is the primary key of the table. The values in this column must be unified, and MySQL will automatically index the column.