mysql_select_db - selects a database as default
  
  - 
    #include <mysql.h>
int mysql_select_db(MYSQL * mysql,
 const char * db);
 
Selects a database as default. Returns zero on success, non-zero
    on failure
  - •
- mysql is a connection identifier, which was
      previously allocated by mysql_init(3) and connected by
      mysql_real_connect(3).
- •
- db - the default database name
  - •
- To retrieve the name of the default database either execute the SQL
      command SELECT DATABASE() or retrieve the value
      via mariadb_get_infov(3) API function.
- •
- The default database can also be set by the db parameter in
      mysql_real_connect(3).
  
  - 
    # switch to default database test
USE test;
# check default database
SELECT DATABASE();
+------------+
| database() |
+------------+
| test       |
+------------+
    
  
  - 
    static int set_default_db(MYSQL *mysql)
{
 int rc;
 char *default_db;
 /* change default database to test */
 rc= mysql_select_db(mysql, "test");
 if (rc)
 return rc;  /* Error */
 /* get the default database */
 rc= mariadb_get_infov(mysql, MARIADB_CONNECTION_SCHEMA, &default_db);
 if (rc)
 return rc; /* Error */
 if (strcmp("test", default_db) != NULL)
 {
 printf("Wrong default database\n");
 return 1;
 }
 printf("Default database: %s", default_db);
 return 0;
}