txi | focused full-text indexing | Natural Language Processing library

you can do this with assign and apply:

There are several issues with this program. A large part of this code relies on undefined behavior. Unions are also UB if used for aliasing, even if pretty much all C compilers tend to allow it, but if you are using a union I would still prefer using a char[] for the array used for aliasing. As mentioned in the comments, "Hi Dave!\r\n"; actually takes up 11 bytes with the null-character. It's safer to use uint8_t myData[] = "Hi Dave!\r\n"; or const * uint8_t = "Hi Dave!\r\n"; and spare yourself the trouble.

Second problem is that strlen cannot work correctly for binary data. strlen works by searching for the first occurrence of the null-character in the string, so it's not applicable for binary data. If you pass a floating point value which has a single zero byte in its IEEE 754 representation, it will mark the end of this "string".

Plain and simple, your function should be declared as fsp_err_t uart_write(const char * msg, size_t msg_len); and be called using uart_write(data_array, sizeof data_array);. If you want to transmit messages of variable size over the UART, you will also have to define a certain communication protocol, i.e. create a message that can be unambiguously parsed. This will likely mean: 1) some cookie at the beginning, 2) length of the transmitted data, 3) actual data, 4) crc -- but this is outside the scope of this question.

So, strlen won't tell you the length of the data, you will pass it to the function yourself, and you don't need unions at all. If you choose not to properly serialize the data (e.g. using protobuf or some other protocol), you can simply pass the pointer to the struct to the function, i.e. call the above mentioned uart_write((char*)&some_struct, sizeof some_struct); and it will work as if you passed an array.

Note that char in this case doesn't mean "ascii character", or "character in a string". The point with using the char* is that it's the only pointer which is legally allowed to alias other pointers. So, you acquire a pointer to your struct (&str), cast it to a char*, and pass it to a function which can then read its representation in memory. I am aware that R_SCI_UART_Write is likely generated by your IDE, and unfortunately these blocks often use uint8_t* instead of char*, so you will probably have to cast to uint8_t* at some point.

A (left) JOIN with an OR condition is usually not very well optimized. But what you can do is create an index on the array of both columns and then change the join condition to use an array operator.

First create the index: