Arduino + Shield Ethernet + Mysql

Using Arduino Networking, Protocols, and Devices
1

Hi does anyone knows some method of pass a variable for this Mysql command:

char QUERY_POP[] = "SELECT credito FROM projeto_development.users WHERE tag = id'";

This id should be a variable but the arduino assigns the name "id" for the search on the database

2 
char Query[120];
int id = 123;

sprintf(Query, "SELECT credito FROM projeto_development.users WHERE tag = %d", id);

Not exactly rocket surgery.