Useful tips for everyday
How to use count ( distinct expr ) in SQL? COUNT() function with distinct clause . SQL COUNT() function with DISTINCT clause eliminates the repetitive…
Why is pgadmin 9.5 not showing all databases? I have a problem with my database. I installed postgreSQL 9.5 on my Ubuntu server. I changed…
Why do you need an index in MongoDB? Indexes also improve efficiency on queries that routinely sort on a given field. If you regularly issue…
Can you use try _ cast in PostgreSQL? It’s hard to wrap something like SQL Server’s TRY_CAST into a generic PostgreSQL function. Input and output…
What does select distinct do in the in subquery? The SELECT DISTINCT in the IN subquery does nothing. Nothing at all. The IN implicitly does…
How do you know if a relation is in BCNF? A relation is in BCNF iff, X is superkey for every functional dependency (FD) X?…
Can you use null instead of NOT NULL in PostgreSQL? PostgreSQL can check the constraint in the list in any order. If you use NULL…
How do I connect to a SQL database from a different server? To create a linked server to another instance of SQL Server Using SQL…
Why use a non-relational database? Non-relational databases are often used when large quantities of complex and diverse data need to be organized. Non-relational databases often…
How long will Postgres 9.6 be supported? After its five year anniversary, a major version will have one last minor release containing any fixes and…