Programming languages

SQL: One of the most valuable skills – Craig Kerstiens

I admit it. I suffered from an “algebra narcoleptic syndrome” during my relational database lessons at University (1996 circa). Ok it is a fake. But it seems so real on these days. I was unable to avoid sleeping. I learned to love SQL after some years and now I think SQL is the most powerful, …

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IoT Async

Qualche mese fa avevo sviluppato una applicazione IoT per misurare la temperatura e spedire i dati ad una coda mqtt. Poi c’era uns server che colelzzionava i dati. Totale: tre server, con tre punti di fallimento ma architettura molto “cool” In effetti però la potenza dei moderni chip embedded è tale che è possibile implementare …

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Removing duplicate rows in PostgreSQL and Oracle

Oracle trick: [sql] DELETE FROM your_table WHERE rowid not in (SELECT MIN(rowid) FROM your_table GROUP BY column1, column2, column3); [/sql] Postgresql equivalent is ctid, so you can try something like [sql] delete from mytable where exists (select 1 from mytable t2 where t2.name = mytable.name and t2.address = mytable.address and t2.zip = mytable.zip and t2.ctid …

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Oracle SQL Developer Keep Alive plugin

On some environment, on some customers, Oracle connections are drop after some idle time (i.e. 2 minutes). I have found a small plugin for Sql Developer to solve this issue: it is very handy and logs its usage. Code is also very clean keepalive extension for Oracle SQL Developer 4+https://github.com/scristalli/SQL-Developer-4-keepalive6 forks.80 stars.7 open issues.Recent commits: Fix …

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Oracle Auto increment trigger HOWTO

Oracle SQL Developer is full of nice feature, damned by a overwhelming options pane, like the one I will describe to you right now. Even if  Oracle databases (<12) does not support auto increment, you can easily ask to your sql data modeler to generate for you a sequence and a trigger in a automatic …

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Oracle Database Sync

Oracle SQL Developer is full of nice feature, damned by a overwhelming options pane, like the one I will describe to you right now. I will show here a very fast way of comparing different database and auto-generate migration script. Reverse engineer the source database using Oracle Data Modeler Now select the right arrow  shown …

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