Database Management Systems
If you’re getting an error that reads “The function ‘RANK’ must have an OVER clause” in SQL Server, it’s probably because you’re calling the RANK() function without an OVER clause.
The RANK() function requires an OVER clause (and that clause must have an ORDER BY clause).
To fix this issue, add an OVER clause when calling the RANK() function.
MySQL has the handy TABLE statement that allows us to get the contents of a table with less code than what we’d need if we’d used the SELECT statement.
When we use the TABLE statement, it returns the columns using the actual column names. In most cases this is fine, and there’s no need to change anything. But sometimes we might want to rename one or more columns. In such cases, we can use the following techniques to achieve that outcome.
When combining multiple query blocks in MySQL, we can use the EXCEPT clause to return just those rows from the first block that are not present in the second block.
If you’re getting an error that reads “The used SELECT statements have a different number of columns” in MySQL, it’s probably because you’re using the EXCEPT, INTERSECT, or UNION clause, but with a different number of columns for each query.
When we use these clauses, both queries must select the same number of columns. For example, if the first query has two columns in its SELECT list, then the second query must also have two columns in its SELECT list.
To fix, make sure both queries select the same number of columns.
Continue readingWhen combining multiple query blocks in MySQL, we can use the INTERSECT clause to return just those rows that are common to both query blocks.
It’s a bit like the UNION clause, except that it excludes rows that aren’t present in both queries.
When using the NTILE() function in SQL Server, we must include an OVER clause clause with an ORDER BY clause.
If you’re getting error msg 4112 that reads “The function ‘NTILE’ must have an OVER clause with ORDER BY” when using the NTILE() function, it’s because, although you’re (correctly) including an OVER clause, you’re omitting the ORDER BY clause.
To fix this error, add an ORDER BY clause to the OVER clause.
When we use the VALUES statement to create a constant table, PostgreSQL automatically names the columns column1, column2, etc. This saves us from having to provide names for the columns or from getting a blank column header.
But we also have the option of naming the columns ourselves.
Continue readingIf you’re getting a SQLite error that reads ‘Parse error: near “LIMIT”‘, it could be that you’re trying to use the LIMIT clause when using the VALUES clause as a stand alone statement.
SQLite doesn’t allow us to apply the LIMIT clause against the VALUES statement.
However, there is a work around. Below is an example of how we can apply the LIMIT clause against the VALUES statement.
If you’re getting SQL Server error 208 that reads “Invalid object name ‘GENERATE_SERIES’“, it could be that you’re calling GENERATE_SERIES() in a version of SQL Server that doesn’t support this function.
The GENERATE_SERIES() function was introduced in SQL Server 2022 (16.x), and so if we try to call it in an earlier version of SQL Server, we’ll get the above error.
So if you’re running this on an earlier version, you’ll need to upgrade before you can run it successfully. You’ll also need to run it on a database with a compatibility level of at least 160.
Continue readingIf you’re getting an error that reads “Parse error: all VALUES must have the same number of terms” in SQLite when using the VALUES clause as a stand alone statement, it’s probably because you’re not providing the same number of columns in all rows.
When we use VALUES to create a constant table, we must provide the same number of columns in each row.
To fix this issue, be sure to provide the same number of columns across all rows.
Continue reading