SQL Server has a CHOOSE() function that returns a list item at a given position. MySQL also has an equivalent function, but with a different name.
In MySQL, the ELT() function does essentially the same thing that CHOOSE() does in SQL Server. It allows you to find the list item at a given position within the list.
In MySQL, you can use the ELT() function to return a list item at a given position in the list.
The syntax goes like this:
ELT(N,str1,str2,str3,...)
Where N is the position of the item you want to return, and str1,str2,str3,... is the list.
Here’s an example:
SELECT ELT(3, 'Marge', 'Homer', 'Bart') AS 'Who is at 3?';
Result:
+--------------+ | Who is at 3? | +--------------+ | Bart | +--------------+
In this case we specify that we want to return the 3rd item in the list (because the first argument is 3) . And in this case the list is 'Marge', 'Homer', 'Bart', so the 3rd item is Bart. Continue reading
In MySQL, you can use the FIELD() function to return the position of a given string or number within a list of arguments. The function returns the index (position) of the first argument in the list of subsequent arguments.
The syntax goes like this:
FIELD(str,str1,str2,str3,...)
Where str is the item you want to find, and str1,str2,str3,... is the list you’re searching through.
Here’s an example:
SELECT FIELD('Homer', 'Marge', 'Homer', 'Bart') AS 'Where is Homer?';
Result:
+-----------------+ | Where is Homer? | +-----------------+ | 2 | +-----------------+
In this example, the list is: 'Marge', 'Homer', 'Bart' and we’re searching for the string Homer within that list. And because Homer is the 2nd item in the list of arguments, the result is 2.
In MySQL, the DATE_FORMAT() function allows you to format the date and time.
Here’s an example:
SELECT DATE_FORMAT('2018-12-01', '%W, %d %M %Y');
Result:
Saturday, 01 December 2018
In this example, %W is for the weekday name, %d is for the day of the month, %M is for Month, and %Y is for Year. There are many more format specifiers available that enable you to specify a precise format for dates, as well as the time component.
In MySQL, you can use the FORMAT() function to format a number to a specific format. This function accepts three parameters; the number, the number of decimal places, and an optional locale.
In MySQL, the CONCAT_WS() function allows you to add a separator to concatenated strings. If you just use the CONCAT() function, you’d have no separator (unless you explicitly added a separator as an argument between each string argument).
A common usage of the CONCAT_WS() function is to create a comma-delimited list.
In SQL Server, you can concatenate two or more strings by using the T-SQL CONCAT() function. You can also use SQL Server’s string concatenation operator (+) to do the same thing. Both are explained here.
In SQL Server (and in any computer programming environment), string concatenation is the operation of joining character strings end-to-end.
Here’s an example:
SELECT CONCAT('Peter', ' ', 'Griffin') AS 'Full Name';
Result:
Full Name ------------- Peter Griffin
Note that I actually concatenated 3 strings here. I concatenated the first name, the last name, plus a space.
MySQL has the CONCAT() function, which allows you to concatenate two or more strings. The function actually allows for one or more arguments, but its main use is to concatenate two or more strings.
In MySQL (and in any computer programming environment), string concatenation is the operation of joining character strings end-to-end.
Here’s an example:
SELECT CONCAT('Homer', ' ', 'Simpson') AS 'Full Name';
Result:
+---------------+ | Full Name | +---------------+ | Homer Simpson | +---------------+
Note that I actually concatenated 3 strings here. I concatenated the first name, the last name, plus a space.
In SQL Server, you can use the LEN() function to return the number of characters in a string. This is a Transact-SQL function that can also be used in Azure databases.
In MySQL, you need to use the CHAR_LENGTH() function.
If you’ve been working with SQL Server for any length of time, you might have encountered the Datalength() function. This function returns the number of bytes used to represent an expression.
But if you’ve moved to MySQL, you may be looking for a function that does the same thing.
In MySQL, the Length() function does basically the same thing that the T-SQL Datalength() function does in SQL Server (and Azure). MySQL’s Length() function returns the length of a string, measured in bytes.
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