How can I repeat a given string 'expr' a certain number of times 'n' in Databricks SQL or Databricks Runtime?
You can use the `repeat` function to repeat a given string `expr` a certain number of times `n` in Databricks SQL or Databricks Runtime. The syntax for the function is `repeat(expr, n)`, where `expr` is the string you want to repeat and `n` is the number of times you want to repeat it. If `n` is less than 1, the function will return an empty string. Here's an example of how to use the function:

> SELECT repeat('123', 2); 123123

In this example, the string '123' is repeated 2 times, resulting in the output '123123'.