SELECT A.*,IFNULL(B.`Name`,'') AS SupplierName,IFNULL(B.ContractUrl,'') AS ContractUrl,IFNULL(c.SName,'') AS SchoolName
SELECT A.*,IFNULL(B.`Name`,'') AS SupplierName,IFNULL(B.ContractUrl,'') AS ContractUrl,IFNULL(c.SName,'') AS SchoolName,IFNULL(D.`Name`,'') AS ProductTypeName
FROM RB_StudyAbroad AS A LEFT JOIN rb_supplier AS B ON A.SupplierId=B.Id
LEFT JOIN rb_school AS C ON A.School_Id=C.SId
LEFT JOIN rb_studyabroad_type AS D ON A.ProductType=D.Id
WHERE 1=1
");
builder.AppendFormat(" AND A.{0}={1}",nameof(RB_StudyAbroad_ViewModel.Status),(int)DateStateEnum.Normal);