Sql 字符集不匹配oracle错误

我有这样一个SQL语句：

SELECT QUOTE_CREATION.*,
       CASE
          WHEN (SUBSTR (QUOTE_CREATION."PO_number", 1, 3)) = 'ARA'
          THEN
             'TE161938'
          WHEN (SUBSTR (QUOTE_CREATION."PO_number", 1, 3)) = 'HH-'
          THEN
             'TE161302'
          WHEN (SUBSTR (QUOTE_CREATION."PO_number", 1, 3)) = 'SMT'
          THEN
             'TE161101'
          WHEN (SUBSTR (QUOTE_CREATION."PO_number", 1, 3)) = 'AYP'
          THEN
             'TE108812'
          WHEN (SUBSTR (QUOTE_CREATION."PO_number", 1, 3)) = 'DKR'
          THEN
             'TE160895'
          ELSE
             QUOTE_CREATION."Created_By"
       END
          AS CORRECT_USER_ID
  FROM CCO.QUOTE_CREATION QUOTE_CREATION

SELECT QUOTE_CREATION.*,
       CASE
          WHEN (SUBSTR (QUOTE_CREATION."PO_number", 1, 3)) = 'ARA'
          THEN
             N'TE161938'
          WHEN (SUBSTR (QUOTE_CREATION."PO_number", 1, 3)) = 'HH-'
          THEN
             N'TE161302'
          WHEN (SUBSTR (QUOTE_CREATION."PO_number", 1, 3)) = 'SMT'
          THEN
             N'TE161101'
          WHEN (SUBSTR (QUOTE_CREATION."PO_number", 1, 3)) = 'AYP'
          THEN
             N'TE108812'
          WHEN (SUBSTR (QUOTE_CREATION."PO_number", 1, 3)) = 'DKR'
          THEN
             N'TE160895'
          ELSE
             QUOTE_CREATION."Created_By"
       END
          AS CORRECT_USER_ID
  FROM CCO.QUOTE_CREATION QUOTE_CREATION

但是当我尝试运行查询时，在大小写表达式的“ELSE”部分出现了一个错误“Character set mismatch”。有人能告诉我哪里做错了吗

多谢各位 桑托沙

引用你的创作。“创作人”可能是

NVARCHAR2

试着这样做：

SELECT QUOTE_CREATION.*,
       CASE
          WHEN (SUBSTR (QUOTE_CREATION."PO_number", 1, 3)) = 'ARA'
          THEN
             'TE161938'
          WHEN (SUBSTR (QUOTE_CREATION."PO_number", 1, 3)) = 'HH-'
          THEN
             'TE161302'
          WHEN (SUBSTR (QUOTE_CREATION."PO_number", 1, 3)) = 'SMT'
          THEN
             'TE161101'
          WHEN (SUBSTR (QUOTE_CREATION."PO_number", 1, 3)) = 'AYP'
          THEN
             'TE108812'
          WHEN (SUBSTR (QUOTE_CREATION."PO_number", 1, 3)) = 'DKR'
          THEN
             'TE160895'
          ELSE
             QUOTE_CREATION."Created_By"
       END
          AS CORRECT_USER_ID
  FROM CCO.QUOTE_CREATION QUOTE_CREATION

SELECT QUOTE_CREATION.*,
       CASE
          WHEN (SUBSTR (QUOTE_CREATION."PO_number", 1, 3)) = 'ARA'
          THEN
             N'TE161938'
          WHEN (SUBSTR (QUOTE_CREATION."PO_number", 1, 3)) = 'HH-'
          THEN
             N'TE161302'
          WHEN (SUBSTR (QUOTE_CREATION."PO_number", 1, 3)) = 'SMT'
          THEN
             N'TE161101'
          WHEN (SUBSTR (QUOTE_CREATION."PO_number", 1, 3)) = 'AYP'
          THEN
             N'TE108812'
          WHEN (SUBSTR (QUOTE_CREATION."PO_number", 1, 3)) = 'DKR'
          THEN
             N'TE160895'
          ELSE
             QUOTE_CREATION."Created_By"
       END
          AS CORRECT_USER_ID
  FROM CCO.QUOTE_CREATION QUOTE_CREATION

---

@IndowKnight这是Oracle中非常有效的语法，当您需要指定包含小写字母的名称时使用。什么是“Created_By”？@Yasir感谢您提供的信息。如果您不介意，请解释我们为什么插入“N”在我们的标准之前，我想这是对Oracle的一个提示，下面的字符串类型是

NCHAR

（Unicode字符集），否则它可能会认为它是

CHAR

。