func getDbDropSQL(al *alias) (sqls []string) {
	if len(modelCache.cache) == 0 {
		fmt.Println("no Model found, need register your model")
		os.Exit(2)
	}
	Q := al.DbBaser.TableQuote()
	for _, mi := range modelCache.allOrdered() {
		sqls = append(sqls, fmt.Sprintf(`DROP TABLE IF EXISTS %s%s%s`, Q, mi.table, Q))
	}
	return sqls
}
create database drop sql.
package orm
import (
	"fmt"
	"os"
	"strings"
)
type dbIndex struct {
	Table string
	Name  string
	SQL   string
}