If you want to use named time zones in MySQL, you’ll need to make sure they’ve been configured.
By “named time zones”, I mean being able to use strings like US/Eastern instead of −04:00 or −05:00 when specifying the time zone. For example, when using the CONVERT_TZ() function.
Here’s how to configure named time zones in MySQL.
If you’re getting error 1045 that reads something like “Access denied for user ‘root’@’localhost’“, it’s because you’re trying to log in to MySQL without the right credentials.
This usually happens when we provide the wrong password. But there could also be another cause. For example, we could be trying to do something as the root user that requires a password, but the root user hasn’t yet had its password set.
To fix this issue, be sure to provide the correct password when connecting to MySQL.
In MySQL, CURRENT_USER() is a built-in function that returns the user name and host name combination for the MySQL account that the server used to authenticate the current client.
In MySQL, USER() is a built-in function that returns the current MySQL user name and host name, given when connecting to MySQL.
The result is returned as a string in the utf8mb3 character set.
The value returned by USER() could be different to the value returned by CURRENT_USER().
When using FOR XML in SQL Server, we can use the ELEMENTS directive to include a column as an element instead of an attribute. However by default, if a column contains a NULL value, no element is produced for that column in the resulting XML document. This may or may not be what we want, depending on the requirements.
If we want such columns to be included in the XML even when they contain NULL values, all we need to do is include the XSINIL option. This option specifies that any column that has a NULL value automatically gets an element with xsi:nil="true" in the resulting XML.
The alternative is ABSENT, which means columns with NULL values are excluded (this is the default behaviour).
When using FOR XML EXPLICIT in SQL Server, we can use the ELEMENT directive to include a column as an element instead of an attribute. However, this directive doesn’t allow for NULL values. What I mean is that if a column contains a NULL value, no element is produced for that column in the resulting XML document. This may or may not be what we want, depending on the requirements.
If we want such columns to be included in the XML even when they contain NULL values, we can use the ELEMENTXSINIL directive instead of ELEMENT.
Trying to convert a number to a date in SQL Server can be tricky and may not always work. It all depends on the number and what exactly it is that we’re trying to do. That said, here are some scenarios where we can convert a number to a date value.
In SQL Server, the FOR XML clause allows us to return the results of a query as an XML document. Simply by placing the FOR XML clause at the end of the query will output the results in XML.
When we do this, we have the option of specifying RAW, AUTO, EXPLICIT, or PATH mode. These modes allow us to shape the resulting XML in different ways, and so the mode we choose will determine how the XML is generated.
Below are examples of using EXPLICIT mode when generating XML from a SQL query.
In SQL Server, the FOR XML clause allows us to return the results of a query as an XML document. Simply by placing the FOR XML clause at the end of the query will output the results in XML.
When we do this, we have the option of specifying RAW, AUTO, EXPLICIT, or PATH mode. These modes allow us to shape the resulting XML in different ways, and so the mode we choose will determine how the XML is generated.
Below are examples of using RAW mode when generating XML from a SQL query.