While adding elements in a bson array, you should call BCON_APPEND_CTX() , but all elements must be placed in the parameter position at once，just like BCON_APPEND_CTX(query, &ctx, "$each", "[", BCON_INT64((int64_t)num[0]), BCON_INT64((int64_t)num[1]), BCON_INT64((int64_t)num[2]) "]") ; However, the number of array elements is unknown, it's difficult to add all elements in the bson array for just calling BCON_APPEND_CTX() one time;
It's need for me to call Call BCON_APPEND_CTX multiple times to add multiple values to the same bson array.