If you’re getting an error that reads something like “Cannot create index on view “demo.dbo.SalesSummary” because it uses the aggregate COUNT. Use COUNT_BIG instead” in SQL Server, it’s because you’re trying to create an index on a view that uses the COUNT() function.
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4 Functions that Trim a String in PostgreSQL
PostgreSQL provides us with various string functions, including some that allow us to trim a given string on both sides or a given side.
Below are four functions that we can use to trim strings in PostgreSQL.
Continue readingFix “Cannot DROP TABLE because it is being referenced by object” in SQL Server (Error 3729)
If you’re getting an error that reads something like “Cannot DROP TABLE ‘dbo.t1’ because it is being referenced by object ‘v1’” in SQL Server, it looks like you’re trying to drop a table that’s referenced by a schema-bound object (such as a schema-bound view).
Continue readingFix “Computed column … in table … is not allowed to be used in another computed-column definition” (Error 1759)
If you’re getting an error that reads something like “Computed column ‘c2’ in table ‘t1’ is not allowed to be used in another computed-column definition” in SQL Server, it appears that you’re trying to create a computed column that uses another computed column.
We can’t use other computed columns in our computed column definitions.
Continue readingIndexed Views in SQL Server: A Complete Guide
Indexed views can significantly enhance the performance of complex queries in SQL Server. However, they come with several prerequisites and considerations that need to be carefully understood before implementation.
In this article, I provide an overview of indexed views, discussing their utility, prerequisites, and best practices, along with performance considerations and a simple example.
Continue readingFix “ALTER TABLE DROP COLUMN failed because one or more objects access this column” in SQL Server (Error 4922)
If you’re getting an error that reads something like “ALTER TABLE DROP COLUMN c2 failed because one or more objects access this column” in SQL Server, it looks like you’re trying to drop a column that’s accessed by another object.
This can happen when we try to drop a column that’s referenced by a schema-bound view. It can happen even when we only try to alter the columns too.
Continue readingImplementing ON UPDATE CASCADE for SQL Server Foreign Keys
ON UPDATE CASCADE is a referential integrity constraint option that we can use in SQL Server when creating foreign keys. It automatically updates foreign key values in child tables when the corresponding primary key in the parent table is updated.
Fix “Cannot create index on view. It contains text, ntext, image, FILESTREAM or xml columns” in SQL Server (Error 1942)
If you’re getting an error that reads something like “Cannot create index on view ‘demo.dbo.v1’. It contains text, ntext, image, FILESTREAM or xml columns” in SQL Server, it appears that you’re trying to create an index on a view that uses an invalid data type.
Not all data types are supported when indexing views.
Continue readingHow to Truncate Tables with Foreign Key Relationships in PostgreSQL
When working with PostgreSQL databases, you may sometimes need to clear out all the data from tables that have foreign key relationships. This process, known as truncation, can be tricky when dealing with interconnected tables.
By default, if we try to truncate a table that is referenced by another table via a foreign key constraint, we’ll get an error that looks something like this: “ERROR: cannot truncate a table referenced in a foreign key constraint“.
You may have encountered this before finding this article. However, all is not lost. Below are two options for overcoming this issue.
Continue readingFix “The new name is already in use as a COLUMN name and would cause a duplicate that is not permitted” in SQL Server (Error 15335)
If you’re getting an error that reads something like “Error: The new name ‘c1’ is already in use as a COLUMN name and would cause a duplicate that is not permitted” in SQL Server, it appears that you’re trying to rename a column with a name that already exists in that table.
Basically, there’s already a column of that name in the table.
Continue reading