[sql] How to create a SQL Server function to "join" multiple rows from a subquery into a single delimited field?

VERSION NOTE: You must be using SQL Server 2005 or greater with Compatibility Level set to 90 or greater for this solution.

See this MSDN article for the first example of creating a user-defined aggregate function that concatenates a set of string values taken from a column in a table.

My humble recommendation would be to leave out the appended comma so you can use your own ad-hoc delimiter, if any.

Referring to the C# version of Example 1:

change:  this.intermediateResult.Append(value.Value).Append(',');
    to:  this.intermediateResult.Append(value.Value);

And

change:  output = this.intermediateResult.ToString(0, this.intermediateResult.Length - 1);
    to:  output = this.intermediateResult.ToString();

That way when you use your custom aggregate, you can opt to use your own delimiter, or none at all, such as:

SELECT dbo.CONCATENATE(column1 + '|') from table1

NOTE: Be careful about the amount of the data you attempt to process in your aggregate. If you try to concatenate thousands of rows or many very large datatypes you may get a .NET Framework error stating "[t]he buffer is insufficient."

Examples related to sql

Passing multiple values for same variable in stored procedure SQL permissions for roles Generic XSLT Search and Replace template Access And/Or exclusions Pyspark: Filter dataframe based on multiple conditions Subtracting 1 day from a timestamp date PYODBC--Data source name not found and no default driver specified select rows in sql with latest date for each ID repeated multiple times ALTER TABLE DROP COLUMN failed because one or more objects access this column Create Local SQL Server database

Examples related to sql-server

Passing multiple values for same variable in stored procedure SQL permissions for roles Count the Number of Tables in a SQL Server Database Visual Studio 2017 does not have Business Intelligence Integration Services/Projects ALTER TABLE DROP COLUMN failed because one or more objects access this column Create Local SQL Server database How to create temp table using Create statement in SQL Server? SQL Query Where Date = Today Minus 7 Days How do I pass a list as a parameter in a stored procedure? SQL Server date format yyyymmdd

Examples related to string-concatenation

How do I concatenate strings? How do I concatenate strings in Swift? How to set the id attribute of a HTML element dynamically with angularjs (1.x)? C++ String Concatenation operator<< how to use concatenate a fixed string and a variable in Python How do I concatenate strings and variables in PowerShell? Concatenating variables in Bash SQL NVARCHAR and VARCHAR Limits Concatenating string and integer in python PHP string concatenation