Question

我从mysql表中获取数据它工作正常，但它在两个字段中显示NULL Status。我希望代替NULL显示0。

这是我的问题：

SELECT ml.GroupID, ml.GroupTitle, ml.GroupDescription, ml.GroupCreatedDateTime, ml.GroupOwnerUserID, ml.ApprovalNeeded, ml.GroupStatus, ml.OrganizationCode, cat.Status
FROM GroupsMaster AS ml
LEFT JOIN UserGroupsMapping cat ON cat.GroupID = ml.GroupID
WHERE ml.OrganizationCode = ?

Answer 1

使用COALESCE运算符

   COALESCE(cat.Status, 0)


SELECT 
 ml.GroupID, 
 ml.GroupTitle, 
 ml.GroupDescription, 
 ml.GroupCreatedDateTime, 
 ml.GroupOwnerUserID, 
 ml.ApprovalNeeded, 
 ml.GroupStatus, 
 ml.OrganizationCode, 
 COALESCE(cat.Status, 0) as Status 
FROM GroupsMaster AS ml 
LEFT JOIN UserGroupsMapping cat ON cat.GroupID = ml.GroupID 
WHERE ml.OrganizationCode = 'ibm'

Answer 2

您可以尝试ifnull()功能。如下：

选择 ifnull （cat.status，0）作为状态
FROM GroupsMaster AS ml LEFT JOIN UserGroupsMapping cat ON cat.GroupID = ml.GroupID WHERE ml.OrganizationCode ='$ organizationCode'“）;

Answer 3

使用此

SELECT 
 ml.GroupID, 
 ml.GroupTitle, 
 ml.GroupDescription, 
 ml.GroupCreatedDateTime, 
 ml.GroupOwnerUserID, 
 ml.ApprovalNeeded, 
 ml.GroupStatus, 
 ml.OrganizationCode, 
 COALESCE(cat.Status, 0) as Status 
FROM GroupsMaster AS ml 
LEFT JOIN UserGroupsMapping cat ON cat.GroupID = ml.GroupID 
and ml.OrganizationCode = 'ibm'

如何在我的sql表中获取数据时显示0而不是NULL

3 个答案: