In SQL, we can use the DROP TABLE IF EXISTS statement to drop a table only if it exists.
While it may seem obvious that we can only drop a table if it exists (i.e. we can’t drop a table that doesn’t exist), there’s a good reason for using this statement.
The reason we put an IF EXISTS clause into a DROP TABLE statement is to prevent any errors that would occur if the table doesn’t exist.
SQL Server 2022 introduced the GENERATE_SERIES() function that allows us to create a series of values that increment between a given start and end point.
We can create a decrementing series simply by having a greater start point than the end point, while omitting the third argument.
We can also create a decrementing series by using a negative value for the third argument. This obviously requires that the start point is higher than the stop point.
Continue readingIf you’re getting the “Operand type clash” error when using the GENERATE_SERIES() function in SQL Server, it’s probably because your arguments aren’t of the same type.
The arguments/operands we provide to the GENERATE_SERIES() function/relational operator need to be of the same type. For example, if we pass an integer as the first argument, then the other arguments must also be an integer.
This error may also come with another error which tells us that the input parameters must be of the same type.
To fix, make sure all arguments are of the same type.
Continue readingSQL Server 2022 introduced the GENERATE_SERIES() function, which enables us to create a series of values within a given range. Although this function is limited to just numeric values, we can still combine it with various other functions to create a series of date/time values.
Below are examples of how we can use the GENERATE_SERIES() function to help us get a list of all dates between two given date values.
MySQL has a LAG() function that we can use to return the value of a previous row of our choosing, based on how many rows back it is from the current row.
Armed with that value, we can then calculate the difference between it and the current row’s value.
Continue readingIf you’re getting SQL Server error 10753 that reads “The function ‘NTILE’ must have an OVER clause”, it’s probably because you’re calling the NTILE() function without an OVER clause.
The NTILE() function requires an OVER clause (and that clause must have an ORDER BY clause).
To fix this issue, be sure to include an OVER clause when calling the NTILE() function.
If you’re getting error 245 that reads something like “Conversion failed when converting the varchar value ‘Five’ to data type int” when using the LEAST() or GREATEST() functions in SQL Server, it’s probably because your arguments aren’t of a comparable data type.
When using LEAST() and GREATEST(), all arguments must be of a data type that is comparable and that can be implicitly converted to the data type of the argument with the highest precedence.
To fix this issue, be sure to pass arguments of comparable data types.
Continue readingIf you have a query that returns multiple columns with numeric values in SQL Server, you can pass them to the GREATEST() function to find out which column has the highest value.
MySQL has a bunch of functions that enable us to get values from another row in the same column. This makes it easy for us to do stuff like calculate the difference between a value in the current row and one in another row, even if it’s in the same column.
Here are five options for calculating the difference between a value in the current row and a value in a different row but in the same column.
Continue readingIf you’re getting SQL Server error number 189 that reads “The greatest function requires 1 to 254 arguments“, it’s probably because you’re either passing too few or too many arguments.
As the error message alludes to, you need to pass at least 1 argument, and no more than 254 arguments when using the GREATEST() function.
To fix this issue, be sure to pass at least 1 argument, and no more than 254 arguments.
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