Mysql DATABASE

Steve junior said:

Tumia kitu inaitwa 'foreign key'

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Steve junior said:

Foreign key ndiyo inayoleta relationship kati ya table, ambapo primary key ya table ya kwanza inakua referenced katika table ya pili kupitia hiyo foreign key, na Kuna aina nyingi za relationship (one to one, one to many, many to many etc) ambapo hata utengenezaji wa it foreign key unategemea aina ya relationship unayoitaka.....ila endelea kujifunza tutorial zipo online

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CREATE TABLE Orders (
    OrderID int NOT NULL,
    OrderNumber int NOT NULL,
    PersonID int,
    PRIMARY KEY (OrderID),
    FOREIGN KEY (PersonID) REFERENCES Persons(PersonID)
);

thesym said:

Constraints za foreign na primary key zinatumika kama

Code:

CREATE TABLE Orders (
    OrderID int NOT NULL,
    OrderNumber int NOT NULL,
    PersonID int,
    PRIMARY KEY (OrderID),
    FOREIGN KEY (PersonID) REFERENCES Persons(PersonID)
);

Ref: SQL FOREIGN KEY Constraint

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