In MySQL, SESSION_USER()
is a synonym for the USER()
function. It returns the current MySQL user name and host name, given when connecting to MySQL.
MySQL SYSTEM_USER() Explained
In MySQL, SYSTEM_USER()
is a synonym for the USER()
function. It returns the current MySQL user name and host name, given when connecting to MySQL.
How to Set Up Named Time Zones in MySQL
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.
Continue readingFix ERROR 1045: “Access denied for user…” 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.
Continue readingMySQL CURRENT_USER() Explained
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.
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 reading