在表中的两列复合上处理具有持久UNIQUE约束的重复项？

Question

I have a number of records that I would like to insert into a MYSQL table. I am using PHP. Some of them are duplicates. I am using the redbeanPHP orm ( http://redbeanphp.com/ )

My strategy is to use a composite UNIQUE constraint made of 2 columns( FIELD A and DUPLICATENUMBER ). When each record is created DUPLICATENUMBER = 0.

Then try to insert the record as follows:

try {             
                 $id = R::store($record);
} catch (Exception $exc) {
---------------

If a duplicate tries to be inserted an error will be generated. I then want to increment DUPLICATENUMBER by 1, and reinsert. This time it should work if both FIELD A and DUPLICATENUMBER have to be the same for the unique constraint to be intact, because incrementing DUPLICATENUMBER , should break the uniqueness. What MYSQL command should I issue to set up this combined Unique constraint?

Thanks in advance,

Bill

Thanks in advance,

Answer 1

您可以选择具有匹配的FIELD A的记录数，并将其设置为DUPLICATENUMBER。