In PostgreSQL, the UNION operator combines the results from multiple queries into a single result set.
Category: DBMS
Database Management Systems
2 Ways to Return Rows that Contain Only Non-Alphanumeric Characters in Oracle
Below are two methods for returning rows that only contain non-alphanumeric characters in Oracle Database.
Alphanumeric characters are alphabetic characters and numeric characters.
Continue readingHow INTERSECT Works in PostgreSQL
In PostgreSQL, the INTERSECT operator combines two queries, but returns only those rows that are returned in both queries.
7 Ways to Find Duplicate Rows in SQL Server while Ignoring any Primary Key
Here are seven options for finding duplicate rows in SQL Server, when those rows have a primary key or other unique identifier column.
In other words, the table contains two or more rows that share exactly the same values across all columns except for its unique identifier column.
Continue readingHow EXCEPT Works in PostgreSQL
In PostgreSQL, the EXCEPT operator returns rows that are returned by the left input query that aren’t returned by the right input query. This can also be referred to as the difference between two queries.
Find All Non-Numeric Values in a Column in MariaDB
If you ever encounter a character column that should be a numeric column, there’s always a possibility that it contains non-numeric data that you don’t know about.
In MariaDB, you can run a query like the following to return non-numeric data from the column.
Continue readingOracle UNION Operator Explained
In Oracle Database, the UNION operator allows us to combine the results from two queries into a single result set.
4 Functions to Format a Number to 2 Decimal Places in SQL Server
When using T-SQL with SQL Server, we can format numbers using various methods, depending on our desired format.
Below are four functions that can be used to format a number to two decimal places in SQL Server.
Continue reading3 Ways to Find Rows that Contain Lowercase Letters in SQLite
Here are three options for returning rows that contain lowercase characters in SQLite.
Continue readingMariaDB MINUS Operator Explained
In MariaDB, the MINUS operator returns distinct rows from the left input query that aren’t output by the right input query.
The MINUS operator was introduced in MariaDB 10.6.1 as a synonym for the EXCEPT operator for the purposes of compatibility with Oracle. Therefore, we can use MINUS and EXCEPT interchangeably (in MariaDB 10.6.1 and later).