只有正数条目的int值

Question

我正在尝试创建一个表，我只能为INT设置正值，我该怎么做？

CREATE TABLE Ingredients(
IngredientID    INTEGER     PRIMARY KEY     NOT NULL,
IngredientName  VARCHAR(255),
IngredientClassID   SMALLINT    NOT NULL,
MeasureAmountID      SMALLINT    NOT NULL
);

Answer 1

试试这个......

CREATE TABLE Ingredients(
IngredientID    INTEGER     PRIMARY KEY,
IngredientName  VARCHAR(255),
IngredientClassID   SMALLINT    NOT NULL,
MeasureAmountID      SMALLINT    NOT NULL,
CHECK (IngredientClassID>0),
CHECK (MeasureAmountID>0)

);

Answer 2

您可以为每列创建Check constraint以仅接受正值。

CREATE TABLE Ingredients(
IngredientID    INTEGER PRIMARY KEY constraint IngredientID_Positive
check (IngredientID >= 0),
IngredientName  VARCHAR(255),
IngredientClassID   SMALLINT    NOT NULL,
MeasureAmountID      SMALLINT    NOT NULL
);