MySQL in a Nutshell, 2nd Edition

Name

mysql_query()

Synopsis

int mysql_query(MYSQL *mysql, const char *query)

Use this function to execute the SQL query given as the second argument of the function. Only one SQL statement may be given. For queries containing binary data, use the mysql_real_query() function instead. This function will return zero if successful, and a nonzero value if not. Here is an example:

...
MYSQL *mysql;
MYSQL_RES *result;
MYSQL_ROW row;
MYSQL_FIELD *field;
int i, num_fields;
...
mysql = mysql_init(NULL);
mysql_real_connect(mysql,host,user,password,database,0,NULL,0);
const char *sql_stmnt = "SELECT * FROM workreq";
mysql_query(mysql, sql_stmnt, bytes);
result = mysql_store_result(mysql);
num_fields = mysql_field_count(mysql);
while((row = mysql_fetch_row(result)) != NULL)
  {
   for(i = 0; i < num_fields; i++)
     { printf("%s, ", row[i]); }
   printf("\n");
  }
mysql_free_result(result);
mysql_close(mysql);
...

Although this example is fairly complete, the lines declaring the variables containing the connection information are not shown. See the example for the msyql_real_connect() function next for those details. The SQL statement in the example is given through a variable, but it could be given within the function if enclosed in double quotes. The results of the query are stored in the result variable by way of the mysql_store_result() function. Incidentally, it’s important to free the memory allocated for the results with the mysql_free_result() function when finished.