In PostgreSQL, we can use the + operator to add one or more weeks to a date. We have a few options when it comes to specifying the actual number of weeks.
Object-Relational
2 Ways to Return Rows that Don’t Contain Numeric Values in Oracle
The following examples return only those rows that don’t contain any numeric digits in a given column in Oracle Database.
Fix “ERROR: each INTERSECT query must have the same number of columns” in PostgreSQL
When using PostgreSQL’s INTERSECT operator, if you encounter an error that reads “ERROR: each INTERSECT 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 INTERSECT operator.
The way to fix this is to ensure that both SELECT statements return the same number of columns.
Add Months to a Date in PostgreSQL
In PostgreSQL, we can use the + operator to add one or more months to a date. There are several options when it comes to specifying the actual number of months.
Fix ‘ERROR: column “colname” does not exist’ in PostgreSQL when using UNION, EXCEPT, or INTERSECT
If you’re getting “ERROR: column “colname” does not exist’” in PostgreSQL when using an operator such as UNION, EXCEPT, or INTERSECT, it may be that you’re trying to reference an aliased column by its column name.
Fix “ERROR: each EXCEPT query must have the same number of columns” in PostgreSQL
When using PostgreSQL’s EXCEPT operator, if you encounter an error that reads “ERROR: each EXCEPT 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 EXCEPT operator.
The way to fix this is to ensure that both SELECT statements return the same number of columns.
Add Days to a Date in PostgreSQL
The + operator allows us to add one or more days to a given date in PostgreSQL. We have a few options when it comes to specifying the actual number of days.
11 Ways to Find Duplicate Rows that have a Primary Key in Oracle
Here are eleven options for returning duplicate rows in Oracle Database when those rows have a primary key or some other unique identifier column and you want to ignore it.
Subtract Days from a Date in PostgreSQL
We can subtract one or more days from a date in PostgreSQL with the - operator.
Fix Error “ORA-01789: query block has incorrect number of result columns”
If you’re getting the error “ORA-01789: query block has incorrect number of result columns” in Oracle Database, then it’s probably because you’re trying to use an operator such as UNION, INTERSECT, or EXCEPT to run a compound query, but the SELECT statements on either side of the operator return a different number of columns.
To fix this, simply ensure that both queries return the same number of columns.