oracle使用另一个表中的列值更新前4个字符

Question

这是我用来从另一个表更新列的查询：

UPDATE SPICES A
  SET A.description = (SELECT CODE
                         FROM CHILLY B
                         WHERE SUBSTR(A.description,1,4) = TRIM(B.desc123))
  WHERE EXISTS (SELECT 1
                  FROM CHILLY B
                  WHERE SUBSTR(A.description,1,4) = TRIM(B.desc123));

但这不是我想要的。要求是使用表CHILLY中的新值（CODE）更新描述的前4个字符。

有什么建议吗？写作查询的新手。

Answer 1

您应该使用连接运算符来添加其余的描述

UPDATE SPICES A
SET A.description = (SELECT CODE
      FROM CHILLY B
      WHERE SUBSTR(A.description,1,4) = TRIM(B.desc123)) || SUSBSTR(A.description, 5, 255 )
WHERE EXISTS (SELECT 1
               FROM CHILLY B
               WHERE SUBSTR(A.description,1,4) = TRIM(B.desc123));