How use PQexecParams in libpq?

Question

I've read the document but still I'm confused how use this function to send this command to server:

INSERT INTO table_1($1,$2,$3);

this function I wrote:

void add_data_to_db(char table){
        const char data[2][2] = {"12","me"};
        re = PQexecParams(connection,
                        "INSERT INTO test_table($1,$2)",
                        2,data,NULL,NULL,NULL,0
                        );
}

but during the compile this error occurs:

db.c: In function ‘add_data_to_db’:
db.c:40:6: warning: passing argument 4 of ‘PQexecParams’ from incompatible pointer type [-Wincompatible-pointer-types]
   40 |    2,data,NULL,NULL,NULL,0
      |      ^~~~
      |      |
      |      const char (*)[2]
In file included from db.c:2:
/usr/include/libpq-fe.h:391:18: note: expected ‘const Oid *’ {aka ‘const unsigned int *’} but argument is of type ‘const char (*)[2]’
  391 | extern PGresult *PQexecParams(PGconn *conn,
      |                  ^~~~~~~~~~~~

Answer 1

The documentation describes PQexecParams:

PGresult *PQexecParams(PGconn *conn,
                       const char *command,
                       int nParams,
                       const Oid *paramTypes,
                       const char * const *paramValues,
                       const int *paramLengths,
                       const int *paramFormats,
                       int resultFormat);

The parameter values are not the fourth, but the fifth argument.

The fourth argument, if not left NULL, is an array with the object IDs describing the types of the parameters.

Note that in C, a string like "me" does not occupy two, but three bytes (you have to include the final zero byte).