SQL只在id不存在的情况下向MYSQL表插入新行 - SQL to only insert a new row into MYSQL table if id does not already exist

SQL to only insert a new row into MYSQL table if id does not already exist

我有一个名为sales的mysql数据库表，列id | timeStamp | timeString | EAN，如果id不存在于表中，我想插入新的值。例如，我可能想添加:

 9997a04fe3f932bf6f8e9d88f4b8dc96 | 0000003082461 | 11:07 (Thu. 22 May. 2014 | 1400716800

如果id '9997a04fe3f932bf6f8e9d88f4b8dc96'之前没有被输入，

到目前为止，我写的SQL看起来像这样:(使用1234作为虚拟值，表中已经有一行，id为1)

 INSERT INTO `sales`(`id`, `timeStamp`, `timeString`, `EAN`) VALUES (1,2,3,4)
    WHERE NOT EXISTS (
        SELECT `id` FROM `sales` WHERE `id` = '1'
    )

请帮助我得到这个SQL语句的工作。现在它报告一个语法错误:

#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'WHERE NOT EXISTS ( SELECT `id` FROM `sales` WHERE `id` = 1 ' at line 2

为ID列添加唯一索引，然后使用INSERT IGNORE语句

在执行INSERT语句之前需要检查数据是否存在。如果退出，只给用户一个消息，数据已经存在或任何你想要的。

这样的

     $result = mysqli_query ($con,"SELECT COUNT(id) FROM sales WHERE (id='$id')");
     $row = mysqli_fetch_row($result);
     $total_records = $row[0];
     if($total_records == 0)
     {
       INSERT INTO sales(`id`, `timeStamp`, `timeString`, `EAN`) VALUES        
       ($id,$timestamp,$timestring,$Ean);   
      } else
      { 
             --------------Enter-----
            ------------Error message------
      }