In Oracle Database, the MINUS operator is used to return only unique rows returned by the first query but not by the second.
Object-Relational
4 Ways to Find Rows that Contain Uppercase Letters in Oracle
Here are four options for returning rows that contain uppercase characters in Oracle Database.
Fix “ERROR: each UNION query must have the same number of columns” in PostgreSQL
When using the UNION operator in PostgreSQL, if you encounter an error that reads “ERROR: each UNION query must have the same number of columns“, it’s because there’s a mismatch in the number of columns returned by the queries on either side of the UNION operator.
This error occurs when the number of columns returned by each SELECT statement is different.
The way to fix this is to ensure that both SELECT statements return the same number of columns.
How UNION Works in PostgreSQL
In PostgreSQL, the UNION operator combines the results from multiple queries into a single result set.
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.
How INTERSECT Works in PostgreSQL
In PostgreSQL, the INTERSECT operator combines two queries, but returns only those rows that are returned in both queries.
How 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.
Oracle UNION Operator Explained
In Oracle Database, the UNION operator allows us to combine the results from two queries into a single result set.
3 Ways to List All Stored Procedures that Reference a Table in PostgreSQL
Here are three examples of returning a list of stored procedures that reference a specific table in PostgreSQL.
3 Ways to List all Triggers for a Given Table in PostgreSQL
Here are three options for listing out the triggers for a given table in PostgreSQL.