问题：
在有sqlserver数据库迁移至Oracle数据库时，遇到将VARCHAR2付给NVARCHAR2问题
原sql
CASE A .kindCode
WHEN ‘2321034‘ THEN ‘02049‘ WHEN ‘2321035‘ THEN ‘11067‘ WHEN ‘2321022‘ THEN ‘11067‘ WHEN ‘2321039‘ THEN ‘02049‘
WHEN ‘2321041‘ THEN ‘10064‘ WHEN ‘2321030‘ THEN ‘10047‘ WHEN ‘2321031‘ THEN ‘10048‘ WHEN ‘2321032‘ THEN ‘02049‘
WHEN ‘2321033‘ THEN ‘02049‘ WHEN ‘2321001‘ THEN ‘11030‘ WHEN ‘2321002‘ THEN ‘10039‘ WHEN ‘2321003‘ THEN ‘10040‘
WHEN ‘2321004‘ THEN ‘10041‘ WHEN ‘2321005‘ THEN ‘10042‘ WHEN ‘2321006‘ THEN ‘02017‘ WHEN ‘2321007‘ THEN ‘02049‘
WHEN ‘2321008‘ THEN ‘02049‘ WHEN ‘2321009‘ THEN ‘11067‘ WHEN ‘2321010‘ THEN ‘11067‘ WHEN ‘2321011‘ THEN ‘11067‘
WHEN ‘2321017‘ THEN ‘02049‘ WHEN ‘2321018‘ THEN ‘02049‘ WHEN ‘2321019‘ THEN ‘02049‘ WHEN ‘2321020‘ THEN ‘04029‘
WHEN ‘2321021‘ THEN ‘02049‘ WHEN ‘2321025‘ THEN ‘02049‘ WHEN ‘2321040‘ THEN ‘02049‘ WHEN ‘2321016‘ THEN ‘02049‘
ELSE ‘2312‘ END AS CLASSESCODE,
修改后
CASE A .kindCode
WHEN CAST(‘2321034‘ as nvarchar2(10)) THEN CAST(‘02049‘as nvarchar2(10)) WHEN CAST(‘2321035‘ as nvarchar2(10)) THEN CAST(‘11067‘as nvarchar2(10))
WHEN CAST(‘2321022‘ as nvarchar2(10)) THEN CAST(‘11067‘as nvarchar2(10)) WHEN CAST(‘2321039‘ as nvarchar2(10)) THEN CAST(‘02049‘as nvarchar2(10))
WHEN CAST(‘2321041‘ as nvarchar2(10)) THEN CAST(‘10064‘as nvarchar2(10)) WHEN CAST(‘2321030‘ as nvarchar2(10)) THEN CAST(‘10047‘as nvarchar2(10))
WHEN CAST(‘2321031‘ as nvarchar2(10)) THEN CAST(‘10048‘as nvarchar2(10)) WHEN CAST(‘2321032‘ as nvarchar2(10)) THEN CAST(‘02049‘as nvarchar2(10))
WHEN CAST(‘2321033‘ as nvarchar2(10)) THEN CAST(‘02049‘as nvarchar2(10)) WHEN CAST(‘2321001‘ as nvarchar2(10)) THEN CAST(‘11030‘as nvarchar2(10))
WHEN CAST(‘2321002‘ as nvarchar2(10)) THEN CAST(‘10039‘as nvarchar2(10)) WHEN CAST(‘2321003‘ as nvarchar2(10)) THEN CAST(‘10040‘as nvarchar2(10))
WHEN CAST(‘2321004‘ as nvarchar2(10)) THEN CAST(‘10041‘as nvarchar2(10)) WHEN CAST(‘2321005‘ as nvarchar2(10)) THEN CAST(‘10042‘as nvarchar2(10))
WHEN CAST(‘2321006‘ as nvarchar2(10)) THEN CAST(‘02017‘as nvarchar2(10)) WHEN CAST(‘2321007‘ as nvarchar2(10)) THEN CAST(‘02049‘as nvarchar2(10))
WHEN CAST(‘2321008‘ as nvarchar2(10)) THEN CAST(‘02049‘as nvarchar2(10)) WHEN CAST(‘2321009‘ as nvarchar2(10)) THEN CAST(‘11067‘as nvarchar2(10))
WHEN CAST(‘2321010‘ as nvarchar2(10)) THEN CAST(‘11067‘as nvarchar2(10)) WHEN CAST(‘2321011‘ as nvarchar2(10)) THEN CAST(‘11067‘as nvarchar2(10))
WHEN CAST(‘2321017‘ as nvarchar2(10)) THEN CAST(‘02049‘as nvarchar2(10)) WHEN CAST(‘2321018‘ as nvarchar2(10)) THEN CAST(‘02049‘as nvarchar2(10))
WHEN CAST(‘2321019‘ as nvarchar2(10)) THEN CAST(‘02049‘as nvarchar2(10)) WHEN CAST(‘2321020‘ as nvarchar2(10)) THEN CAST(‘04029‘as nvarchar2(10))
WHEN CAST(‘2321021‘ as nvarchar2(10)) THEN CAST(‘02049‘as nvarchar2(10)) WHEN CAST(‘2321025‘ as nvarchar2(10)) THEN CAST(‘02049‘as nvarchar2(10))
WHEN CAST(‘2321040‘ as nvarchar2(10)) THEN CAST(‘02049‘as nvarchar2(10)) WHEN CAST(‘2321016‘ as nvarchar2(10)) THEN CAST(‘02049‘as nvarchar2(10))
ELSE CAST(‘2312‘ as nvarchar2(10)) END AS CLASSESCODE,
详细问题：https://blog.csdn.net/liuxiyangyang/article/details/8446692
Oracle数据库中，使用case语句，遇到VARCHAR2与NVARCHAR2问题
原文：https://www.cnblogs.com/zhxb/p/9777249.html