將 OUTER APPLY 轉換為 Oracle 11g 語句

Question

我有以下 TSQL，

select 2*EC.Total C1, T1.C2, EC.Total
FROM MyTable1 T1 
OUTER APPLY (select COUNT(*) AS Total from MyTable2 T2 WHERE T1.SomeColumn=T2.SomeColumn ) EC
ORDER BY EC.Total desc

我需要將其轉換為 Oracle 11g。 我試過橫向但不支持。

Answer 1

你真的不需要橫向連接：

select 2*EC.Total C1, T1.C2, EC.Total
FROM MyTable1 T1 
  LEFT JOIN (
    select m2.somecolumn, COUNT(*) AS Total 
    from MyTable2 m2
    group by m2.somecolumn
  ) ec ON t1.somecolumn = ec.somecolumn
ORDER BY EC.Total desc