我使用case語句和子查詢創建一個視圖,它被執行,並顯示埃羅ORA-01427:單行子查詢返回不止
ORA-01427 "single-row subquery returns more than one row"
我怎麼能只返回一行來解決它?
CREATE OR REPLACE FORCE VIEW AAAA("BB", "CC") AS
SELECT T1.C1,
CASE WHEN T2.C1='RED' THEN (SELECT COLOR_RED FROM T1)
WHEN T2.C1='GREEN' THEN (SELECT COLOR_GREEN FROM T1)
WHEN T2.C1='BLUE' THEN (SELECT COLOR_BLUE FROM T1)
ELSE NULL END
FROM T1, T2;
'... THEN color_red'等 – Mihai 2014-11-06 15:00:15