//新增字段

private function create_field($tbl,$field)

{

$sql = "alter table {$tbl} add {$field}";

dd($sql,'',1);

$res = M()->execute($sql);

dd($res,'');

}

private function update_sql($tbl,$update)

{

$sql = "update {$tbl} set {$update}";

dd($sql,'',1);

//$res = M()->query($sql);

//dd($res,'');

}

//删除索引

private function drop_index($tbl,$index)

{

$sql ="alter table {$tbl} drop index {$index}" ;

dd($sql,'');

$res = M()->execute($sql);

dd($res,'');

}

//增加索引

private function create_index($tbl,$field)

{

$sql ="alter table {$tbl} add index index_time ($field)";

dd($sql,'');

$res = M()->execute($sql);

dd($res,'');

}