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.
Author: Ian
MySQL USER() Explained
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()
.
How to Include Elements that Contain NULL Values When Using FOR XML in SQL Server
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).
How to Include Elements that Contain NULL Values When Using FOR XML EXPLICIT in SQL Server
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
.
Convert a Number to a Date in SQL Server
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.
Continue readingRedis ZRANGESTORE Command Explained
In Redis, the ZRANGESTORE
command works just like the ZRANGE
command except that it stores the result in a key.
Basically, it allows us to get all members from a sorted set between a certain range and store them in a new key.
Continue readingSQL Server FOR XML EXPLICIT Examples
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.
SQL Server FOR XML RAW Examples
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.
Fix “ERR wrong number of arguments for ‘srandmember’ command” in Redis
If you’re getting an error that reads “ERR wrong number of arguments for ‘srandmember’ command” in Redis, it’s probably because you’re calling the SRANDMEMBER
command without any arguments.
To fix this issue, make sure you pass the correct number of arguments. At the time of writing, the SRANDMEMBER
command requires at least one argument, and accepts an optional second argument.
SQL Server FOR XML AUTO Examples
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 AUTO
mode when generating XML from a SQL query.