tdenginewriter写入cassandra的json字符串失败

相关错误日志如下：
ERROR convert nchar string to UCS4_LE failed:{"carNumber":"","image":"","outParkingSpace":1638927251000,"parkingSpaceStatus":0}
02/20 18:21:18.947000 00150464 TSC ERROR 0xf bind column 4: type mismatch or invalid
02/20 18:21:18.947000 00150464 JNI ERROR jobj:00000069469FE648, conn:000001CC512F7AA0, code:Invalid operation

The issue names the TDengineWriter-to-Cassandra write path but provides no file, test, or entry point. Start by locating that writer and reproducing the logged JSON-string conversion and column-binding errors. Done means the reported JSON string is written successfully without the UCS4_LE conversion or type-mismatch errors.

Written by the indexing model from the issue text.