If you’re getting error 1298 that reads something like “ERROR 1298 (HY000): Unknown or incorrect time zone: ‘UTC’” in MySQL, it’s probably because you’re specifying a time zone name, but your MySQL installation hasn’t yet been configured for named time zones.
To fix this issue, be sure that your MySQL installation has been configured for named time zones.
Continue readingIf you’re getting an error that reads something like “lastval is not yet defined in this session” when calling the lastval() function in PostgreSQL, it’s probably because nextval() hasn’t yet been called in the current session.
If you want to avoid this error, only call the lastval() function when you know that nextval() has been called at least once in the current session.
If you’re getting error msg 237 that reads There is insufficient result space to convert a money value to int, it’s because you’re trying to convert a money value to an integer but the number’s too big to fit into an integer.
To fix this issue, make sure you convert the value to a data type that can handle the size of the number that you’re trying to convert.
Continue readingIf you’re getting an error that reads something like “Cannot DROP SEQUENCE ‘Sequence2’ because it is being referenced by object ‘DF__Dogs__DogId__6C190EBB’“, it could be because you’re trying to drop a sequence object that’s referenced by a DEFAULT constraint.
Sequences that are referenced by a DEFAULT constraint can’t be dropped until the DEFAULT constraint is dropped.
Therefore, to fix this issue, drop the DEFAULT constraint first.
Below are seven functions we can use to extract the hours, minutes, seconds, and microseconds from a time value in MySQL.
Continue readingIf you get an error that reads “WRONGTYPE Operation against a key holding the wrong kind of value” when using the ZREM command in Redis, it’s because you’re passing a key with the wrong data type.
To fix this issue, make sure that you pass a sorted set to the ZREM command.
By default, SQL Server sets its own minimum and maximum values for sequence objects based on the data type of the sequence object. Assuming we don’t set the data type for the sequence, these min/max values are based on the bigint data type (because that’s the default data type for sequence objects in SQL Server).
However, we can also set our own minimum and maximum values for our sequences. We can do this either explicitly (by setting the MAXVALUE and MINVALUE properties) or implicitly (by setting the data type).
If you’re getting an error that reads something like “START value (0) cannot be less than MINVALUE (1)” in PostgreSQL when you’re trying to create a sequence, it’s because your sequence’s start value is lower than its minimum value, when it should be at least the same or higher.
To fix this issue, be sure that the sequence’s start value is at least the same or greater than the minimum value.
Continue readingIn Redis, we can update multiple fields in just the same way that we can update a single field. The HSET command allows us to set one or more fields in a hash.
The ability of the HSET command to update multiple fields was introduced in Redis 4.0.0. Prior to that, we needed to use the (now deprecated) HMSET command if we wanted to add more than one field at once.
If you’re getting error msg 6825 that reads “ELEMENTS option is only allowed in RAW, AUTO, and PATH modes of FOR XML“, it’s probably because you’re trying to use the ELEMENTS directive while using EXPLICIT mode of the FOR XML clause.
As the message alludes to, this option is not available when using the EXPLICIT mode (it’s only allowed with the RAW, AUTO, and PATH modes).
However, SQL Server does provide us with an equivalent that provides the same result. When using EXPLICIT mode, we can use the ELEMENT directive instead. We apply this to the column names, instead of the end of the query. We can alternatively use the ELEMENTXSINIL directive to ensure that elements are generated even if the column contains a NULL value.