[Add single quotation marks to nchar fields when export to a file]

src/kit/shell/shellEngine.c

@@ -480,7 +480,7 @@ int shellDumpResult(TAOS *con, char *fname, int *error_no) {
               case TSDB_DATA_TYPE_NCHAR:
                 memset(t_str, 0, TSDB_MAX_BYTES_PER_ROW);
                 memcpy(t_str, row[i], fields[i].bytes);
-                fprintf(fp, "%s", t_str);
+                fprintf(fp, "\'%s\'", t_str);
                 break;
               case TSDB_DATA_TYPE_TIMESTAMP:
                 fprintf(fp, "%ld", *(int64_t *)row[i]);