INT值只有正值條目

Question

我正在嘗試創建一個表，並且我只能對INT具有正值，我該怎麼做？

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

Answer 1

試試這個...上_column_

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

您可以爲每列創建一個Check constraint以僅接受正值。

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