Selecting unique records in a MySQL query: select distinct

Using the distinct construct is relevant not only for selecting unique entries. This is a good way to test the application. The main semantic load on the select distinct MySQL query keyword is to select only those records in which the specified field has a unique value.

You can use multiple fields in a single query. You can combine fields with MySQL functions, apply additional conditions in the selection and sorting. Using the group by construct is also acceptable, but the uncertainties that arise from this must be taken into account.

Basic Provisions and Syntax

Testing and optimization: select distinct is one of the most popular ways to achieve what you want. A case in point is a table containing 99,999 records, which are randomly generated from three arrays:

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