PostgreSQL 5 results

ALL YOU WANT TO KNOW ABOUT VIEWS

WHAT IS A VIEW? In a short sentence, a view is a “saved query” associated with a name. Once you create the view (or save the query), you can use it as a table in other queries. Trying to explain with more detail what a view is, we can say that a view is another type of database objects like tables, indexes or stored procedures. From a point of view of a developer who is trying to write a SELECT query, a view is like any other regular table. The view can be used in the FROM clause as any ...

DATE / TIME ARITHMETIC WITH TEAMSQL

In this article, we will cover some interesting operations involving date and time data values in SQL. The SQL standard specifies the following date and time-related data types that must be present in relational databases: date, time, timestamp and interval. -  date: Represents a single day. Example 15/12/2018 -  time: Represents the time with hour, minutes, seconds. Example 09:14:30 -  timestamp: Represents a point in the timeline. Example 2018-12-15 09:14:30 -  interval: Repres...

SQL COALESCE Function

The first time I saw the term COALESCE in a SQL manual, I thought it was a scientific function for some complex calculation. However, later I found that it is a straightforward and handy function. In this article, I will show several examples to explain how to use the COALESCE function.   THE REASON BEHIND COALESCE: THE NULL VALUE Before go deep with COALESCE function, the reader needs to understand how the NULL value works in some expressions. A NULL value in a table column means ...

Emulating UPSERT in PostgreSQL

Upsert is an interesting and powerful SQL statement not supported on all database managers. In this article we will cover a technique to emulate the upsert statement with other regular SQL statements in PostgreSQL. You can apply this technique in other database engines too.     The UPSERT statement The upsert statement is used when we have two tables. One is the destination table, where we will do updates or inserts (hence the name upsert) and the other table is the source ...

Using the CREATE Procedure and INSERT INTO Statement Templates

TeamSQL comes with built-in templates to guide you as you create new procedures or statements that change your databases. In this article, we’ll cover using the CREATE Procedure and INSERT INTO Statement Templates.   Procedure Template: CREATE In a new TeamSQL query tab, begin typing CREATE. Notice that, as you type, the drop down menu of options filters. When you see CREATE PROCEDURE highlighted, you can hit the ENTER key to populate the window with a CREATE stored procedure ...