[Solved] MySQL distinct doesn\'t return Distinct Values

How to optimize this SQL query?

In case you have your own slow SQL query, you can optimize it automatically here.

For the query above, the following recommendations will be helpful as part of the SQL tuning process.
You'll find 3 sections below:

  1. Description of the steps you can take to speed up the query.
  2. The optimal indexes for this query, which you can copy and create in your database.
  3. An automatically re-written query you can copy and execute in your database.
The optimization process and recommendations:
  1. Use Numeric Column Types For Numeric Values (query line: 12): Referencing a numeric value (e.g. 46) as a string in a WHERE clause might result in poor performance. Possible impacts of storing numbers as varchars: more space will be used, you won't be able to perform arithmetic operations, the data won't be self-validated, aggregation functions like SUM won't work, the output may sort incorrectly and more. If the column is numeric, remove the quotes from the constant value, to make sure a numeric comparison is done.
The optimized query:
SELECT
        DISTINCT (market_devices.deviceId),
        market_devices.id,
        market_devices.registerId,
        deviceOs 
    FROM
        market_devices_link 
    INNER JOIN
        market_devices 
            ON market_devices_link.deviceId = market_devices.id 
    WHERE
        market_devices_link.shopid = '46' 
        AND (
            market_devices.deviceId IS NOT NULL 
            AND market_devices.registerId IS NOT NULL
        ) 
        AND market_devices.registerId NOT LIKE 'NO_NOTIFICATION%'

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* original question posted on StackOverflow here.