Skip to main content

SQL SERVER – Creating Comma Separate Values List from Table – UDF – SP

 Following script will create common separate values (CSV) or common separate list from tables. convert list to table. Following script is written for SQL SERVER 2005. It will also work well with very big TEXT field. If you want to use this on SQL SERVER 2000 replace VARCHAR(MAX) with VARCHAR(8000) or any other varchar limit. It will work with INT as well as VARCHAR.

There are three ways to do this. 1) Using COALESCE 2) Using SELECT Smartly 3) Using CURSOR.

The table is example is:
TableName: NumberTable

NumberCols
first
second
third
fourth
fifth

Output : first,second,third,fourth,fifth

Option 1: This is the smartest way.
DECLARE @listStr VARCHAR(MAX)
SELECT @listStr = COALESCE(@listStr+',' , '') + NumberCols
FROM NumberTable
SELECT @listStr
Please make a note that COALESCE returns the first NOT NULL value from the argument list we pass.

Option 2: This is the smart but not the best way; though I have seen similar code many times.
DECLARE @listStr VARCHAR(MAX)
SET @listStr = ''
SELECT @listStr = @listStr + NumberCols + ','
FROM NumberTable
SELECT SUBSTRING(@listStr , 1, LEN(@listStr)-1)
I sometime use ISNULL(NumberCols,’NullValue’) to convert NULL values to other desired value.

Comments

Post a Comment

Popular posts from this blog

Select Names from table which have vowels

  Problem Query the list of  CITY  names from  table  which have vowels (i.e.,  a ,  e ,  i ,  o , and  u ) as both their first  and  last characters. Your result cannot contain duplicates. Input Format The  STATION  table is described as follows: Field Type ID NUMBER CITY VARCHAR2(21) STATE VARCHAR2(2) LAT_N NUMBER LONG_W NUMBER STATION where  LAT_N  is the northern latitude and  LONG_W  is the western longitude. MYSQL select distinct city from station where (city like 'a%' or city like 'e%' or city like 'i%' or city like 'o%' or city like 'u%' ) and ( city like '%a' or city like '%e' or city like '%i' or city like '%o' or city like '%u' )
1 comment
Read more
Q- What will be the result of the query below? Explain your answer and provide a version that behaves correctly. select case when null = null then 'Yup' else 'Nope' end as Result; Ans-This query will actually yield “Nope”, seeming to imply that  null  is not equal to itself! The reason for this is that the proper way to compare a value to  null  in SQL is with the  is  operator, not with  = . Accordingly, the correct version of the above query that yields the expected result (i.e., “Yup”) would be as follows: select case when null is null then 'Yup' else 'Nope' end as Result;
Post a Comment
Read more

Methods of Rank Rows in SQL Server: ROW_NUMBER(), RANK(), DENSE_RANK() and NTILE()

SQL Server provides us with a number of window functions that help us to perform calculations across a set of rows, without the need to repeat the calls to the database. Unlike the standard aggregate functions, the window functions will not group the rows into a single output row, they will return a single aggregated value for each row, keeping the separate identities for those rows. The Window term here is not related to the Microsoft Windows operating system, it describes the set of rows that the function will process. One of the most useful types of window functions is Ranking Window Functions that are used to rank specific field values and categorize them according to the rank of each row, resulting in a single aggregated value for each participated row. There are four ranking window functions supported in SQL Server;  ROW_NUMBER(),   RANK() ,  DENSE_RANK()  and  NTILE() . All these functions are used to calculate ROWID for the provided rows window in ...
Post a Comment
Read more