How To Use Comma Separated Values In Sql
While it s true that you could achieve this same effect prior to sql server 2017 it was a bit fiddly.
How to use comma separated values in sql. Convert rows into comma separated values in a column 12 jan 1 2015 in sql server tagged row concatenation xml by gopal krishna ranjan in this post we are going to learn a technique to combine all the values of a row based on a particular condition with a separator in a column along with other columns. This means you can have your result set appear as a comma separated list a space separated list or whatever separator you choose to use. Lets split the comma separated phone number list into columns for this we will use cross apply operator string split function and sql pivot. We will learn today how to split comma separated value string in a column using string split. For converting a comma separated value to rows i have written a user defined function to return a table with values in rows.
A typical example of this is when a column can store multiple values separated by a comma. Starting with sql server 2017 you can now make your query results appear as a list. For example if you have following resultset and if you want each of the value of the comma separated string from the last column in a separate row previously you had to use a very complicated function on the column which was a performance killer. Sometimes database tables are not normalized. Now the first question is how to get the comma separated values the answer is that using for xml path we can determine the comma separated values from n number of rows for a single column.
In order to fetch the comma separated delimited values from the stored procedure you need to make use of a variable with data type and size same as the output parameter and pass it as output parameter using output keyword. Now for the perfect comma separated value we must remove the first comma in the above query result. Declare employeeids varchar 200 exec getemployeesbycity london employeeids output. Columns phn1 phn2 phn3 phn4 will be having a phone number values. This can be done using stuff or the substring function.
The string split can help normalize the data by splitting these multi valued columns. It s pretty obvious how it works the only complexity is the replace part which ensures the string is terminated with a single comma by appending one and removing all double commas from the string. B using string split function to split a comma separated string in a column.