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docs/en/sql-reference/aggregate-functions/reference/groupconcat.md

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+---
+slug: /en/sql-reference/aggregate-functions/reference/groupconcat
+sidebar_position: 363
+sidebar_label: groupConcat
+title: groupConcat
+---
+
+Calculates a concatenated string from a group of strings, optionally separated by a delimiter, and optionally limited by a maximum number of elements.
+
+**Syntax**
+
+``` sql
+groupConcat(expression [, delimiter] [, limit]);
+```
+
+**Arguments**
+
+- `expression` — The expression or column name that outputs strings to be concatenated..
+- `delimiter` — A [string](../../../sql-reference/data-types/string.md) that will be used to separate concatenated values. This parameter is optional and defaults to an empty string if not specified.
+- `limit` — A positive [integer](../../../sql-reference/data-types/int-uint.md) specifying the maximum number of elements to concatenate. If more elements are present, excess elements are ignored. This parameter is optional.
+
+:::note
+If delimiter is specified without limit, it must be the first parameter following the expression. If both delimiter and limit are specified, delimiter must precede limit.
+:::
+
+**Returned value**
+
+- Returns a [string](../../../sql-reference/data-types/string.md) consisting of the concatenated values of the column or expression. If the group has no elements or only null elements, and the function does not specify a handling for only null values, the result is a nullable string with a null value.
+
+**Examples**
+
+Input table:
+
+``` text
+┌─id─┬─name─┐
+│ 1  │  John│
+│ 2  │  Jane│
+│ 3  │   Bob│
+└────┴──────┘
+```
+
+1.	Basic usage without a delimiter:
+
+Query:
+
+``` sql
+SELECT groupConcat(Name) FROM Employees;
+```
+
+Result:
+
+``` text
+JohnJaneBob
+```
+
+This concatenates all names into one continuous string without any separator.
+
+
+2. Using comma as a delimiter:
+
+Query:
+
+``` sql
+SELECT groupConcat(Name, ', ', 2) FROM Employees;
+```
+
+Result:
+
+``` text
+John, Jane, Bob
+```
+
+This output shows the names separated by a comma followed by a space.
+
+
+3. Limiting the number of concatenated elements
+
+Query:
+
+``` sql
+SELECT groupConcat(Name, ', ', 2) FROM Employees;
+```
+
+Result:
+
+``` text
+John, Jane
+```
+
+This query limits the output to the first two names, even though there are more names in the table.