// NewStatus returns a *Status structure to the user
func NewStatus(dbh *sql.DB) *Status {
if dbh == nil {
logger.Fatal("NewStatus() dbh is nil")
}
s := new(Status)
s.dbh = dbh
return s
}
// NewVariables returns a pointer to an initialised Variables structure
func NewVariables(dbh *sql.DB) *Variables {
if dbh == nil {
logger.Fatal("NewVariables(): dbh == nil")
}
v := new(Variables)
v.dbh = dbh
v.selectAll()
return v
}
// Get returns the value of the variable name requested (if found), or if not an error
// - note: we assume we have checked a variable first as there's no logic here to switch between I_S and P_S
func (status *Status) Get(name string) int {
var value int
query := "SELECT VARIABLE_VALUE from " + globalVariablesSchema + ".GLOBAL_STATUS WHERE VARIABLE_NAME = ?"
err := status.dbh.QueryRow(query, name).Scan(&value)
switch {
case err == sql.ErrNoRows:
logger.Println("global.SelectStatusByName(" + name + "): no status with this name")
case err != nil:
logger.Fatal(err)
default:
// fmt.Println("value for", name, "is", value)
}
if err != nil {
logger.Fatal("Unable to retrieve status for '"+name+"':", err)
}
return value
}
// selectAll() collects all variables from the database and stores for later use.
// - all returned keys are lower-cased.
func (v *Variables) selectAll() {
hashref := make(map[string]string)
query := "SELECT VARIABLE_NAME, VARIABLE_VALUE FROM " + globalVariablesSchema + ".GLOBAL_VARIABLES"
logger.Println("query:", query)
rows, err := v.dbh.Query(query)
if err != nil {
if (globalVariablesSchema == "INFORMATION_SCHEMA") && (err.Error() == showCompatibility56Error) {
logger.Println("selectAll() I_S query failed, trying with P_S")
globalVariablesSchema = "PERFORMANCE_SCHEMA" // Change global variable to use P_S
query = "SELECT VARIABLE_NAME, VARIABLE_VALUE FROM " + globalVariablesSchema + ".GLOBAL_VARIABLES"
logger.Println("query:", query)
rows, err = v.dbh.Query(query)
}
if err != nil {
logger.Fatal("selectAll() query failed with:", err)
}
}
logger.Println("selectAll() query succeeded")
defer rows.Close()
for rows.Next() {
var variable, value string
if err := rows.Scan(&variable, &value); err != nil {
logger.Fatal(err)
}
hashref[strings.ToLower(variable)] = value
}
if err := rows.Err(); err != nil {
logger.Fatal(err)
}
logger.Println("selectAll() result has", len(hashref), "rows")
v.variables = hashref
}
