Question

avg

获得某个列字段的平均值

avg($table, $column, $where)

• table [string]

  表名.

• column [string]

  列字段

• where (optional) [array]

  WHERE 条件.

avg($table, $join, $column, $where)

• table [string]

  The table name.

• join [array]

  Table relativity for table joining.

• column [string]

  The target column will be calculated.

• where (optional) [array]

  The WHERE clause to filter records.

Return: [number] 平均值.

$average = $database->avg("account", "age", [    "gender" => "male"]);echo "The average age of male user is " . $average;