ODBC (Open Database Connectivity) drivers allow connection to many databases out of the box. In Windows and Qt you can use ODBC Plugin (for Qt) to connect to those databases.
Continue reading “How to use ODBC in Qt”How to use ODBC in Qt
Handling Duplicate Records in SQL
This happens a lot (to me at least 🙂 ) so I decided to make a note here!
Following SQL script will allow you to SELECT duplicate records in a given table.
SELECT * FROM my_table WHERE some_field IN (SELECT some_field FROM my_table GROUP BY some_field HAVING COUNT(some_field) > 1)This code actually finds all the records in a table named “my_table” which have the same value for a field (or column) named “some_field” in more than 1 records which is specified in the final clause COUNT(some_field) > 1
To delete (remove) duplicate records you only need to change “SELECT *” to “DELETE”.
DELETE FROM my_table WHERE some_field IN (SELECT some_field FROM my_table GROUP BY some_field HAVING COUNT(some_field) > 1)