categoryID是模糊的mysql

Question

CREATE DEFINER=`sqladmin`@`%` PROCEDURE `sp_getContainerSize`(IN P_ProjectId INT, IN P_CategoryName VARCHAR(45))
BEGIN
SELECT  ContainerName,LocationPath,ContainerDesc,ContainerSize,categoryId, ContainerUsed,ContainerSize-ContainerUsed as free,concat(round(100*((ContainerSize-ContainerUsed)/ContainerSize ),2), '%') as PercentageFreeContainer
FROM Container 
inner join Location on Container.locationId=Location.locationId    
where projectID=P_ProjectId;     
END

It says my categoryId is ambiguous - may I ask why?

Answer 1

So you have to use alias name for table to fix this problem. hence your query will be like the following:

SELECT  a.ContainerName,a.LocationPath,a.ContainerDesc, 
a.ContainerSize,a.categoryId,a.ContainerUsed,a.ContainerSize-a.ContainerUsed as free, 
concat(round(100*((a.ContainerSize-a.ContainerUsed)/a.ContainerSize ),2), '%')as PercentageFreeContainer
FROM Container a
inner join Location b on a.locationId=b.locationId    
where a.projectID=P_ProjectId ;