How Can I Generate Numbered Rows from a SQL Table with Repeated Values?

Numbering Rows with Repeated Values in SQL Tables

This SQL construct offers a solution to a common problem: expanding results to include repeated rows, each with an assigned index. The desired output converts a table with a "count" column into a table where rows with a count greater than 1 appear multiplied, with each new row assigned a numerical index.

To cater to the varying syntax of major databases, a versatile approach is presented using the "Numbers" table, a common tool in SQL. This table, which is created with the appropriate syntax for each database, contains a series of sequential numbers.

By joining the original table with the Numbers table, we use the count column as a filter to ensure that only rows with counts less than the number of rows in Numbers are included. This allows each row's count to directly determine the number of times it will be repeated in the output.

Finally, the required columns are projected, typically involving value, count, and index (or number). This technique provides a database-independent solution for multiplying rows and assigning numerical indexes, ensuring consistent results across various platforms.

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