在放弃之前检查是否存在

Created: November-22, 2018

MySQL >= 3.19

DROP TABLE IF EXISTS MyTable;

PostgreSQL >= 8.x

DROP TABLE IF EXISTS MyTable;

SQL Server >= 2005

If Exists(Select * From Information_Schema.Tables
          Where Table_Schema = 'dbo'
            And Table_Name = 'MyTable')
  Drop Table dbo.MyTable

SQLite >= 3.0

DROP TABLE IF EXISTS MyTable;