panbingkun commented on code in PR #45334: URL: https://github.com/apache/spark/pull/45334#discussion_r1507220727
########## sql/core/src/main/scala/org/apache/spark/sql/functions.scala: ########## @@ -41,22 +41,20 @@ import org.apache.spark.sql.types.DataType.parseTypeWithFallback import org.apache.spark.util.Utils /** - * Commonly used functions available for DataFrame operations. Using functions defined here provides - * a little bit more compile-time safety to make sure the function exists. + * Commonly used functions available for DataFrame operations. Using functions defined here + * provides a little bit more compile-time safety to make sure the function exists. * - * Spark also includes more built-in functions that are less common and are not defined here. - * You can still access them (and all the functions defined here) using the `functions.expr()` API - * and calling them through a SQL expression string. You can find the entire list of functions - * at SQL API documentation of your Spark version, see also - * <a href="https://spark.apache.org/docs/latest/api/sql/index.html";>the latest list</a> + * You can call the functions defined here by two ways: `_FUNC_(...)` and + * `functions.expr("_FUNC_(...)")`. * - * As an example, `isnan` is a function that is defined here. You can use `isnan(col("myCol"))` - * to invoke the `isnan` function. This way the programming language's compiler ensures `isnan` - * exists and is of the proper form. You can also use `expr("isnan(myCol)")` function to invoke the - * same function. In this case, Spark itself will ensure `isnan` exists when it analyzes the query. + * As an example, `regr_count` is a function that is defined here. You can use + * `regr_count(col("yCol", col("xCol")))` to invoke the `regr_count` function. This way the + * programming language's compiler ensures `regr_count` exists and is of the proper form. You can + * also use `expr("regr_count(yCol, xCol)")` function to invoke the same function. In this case, + * Spark itself will ensure `regr_count` exists when it analyzes the query. * - * `regr_count` is an example of a function that is built-in but not defined here, because it is Review Comment: Obviously, when we were developing the `connect module`, the function `regr_count` was already implemented here. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org
