MySQL Aggregate Function: GROUP_CONCAT() for List Construction
Aggregate functions play a vital role in data summarization and manipulation. One such function, commonly encountered in applications, is the need to aggregate strings into a list. While Oracle provides the LISTAGG function, MySQL offers a similar solution with the GROUP_CONCAT() function.
To concatenate a list of strings, simply use the GROUP_CONCAT() function with an appropriate separator. For instance, to generate a comma-separated list of the MyString column for rows where the Id column is less than 4, you can execute the following query:
SELECT GROUP_CONCAT(MyString SEPARATOR ', ') AS myList FROM table WHERE id < 4;
The GROUP_CONCAT() function aggregates all values in the MyString column, separated by commas, and assigns the resulting list to the alias myList. The result will be a single row with the concatenated string as its value:
myList ------------------------ First, Second, Third
This provides a straightforward and efficient way to aggregate strings into a list-like structure, making it useful for various reporting and data manipulation scenarios.
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