comphead commented on code in PR #13102: URL: https://github.com/apache/datafusion/pull/13102#discussion_r1817370247
########## docs/source/user-guide/sql/special_functions.md: ########## @@ -0,0 +1,94 @@ +<!--- + Licensed to the Apache Software Foundation (ASF) under one + or more contributor license agreements. See the NOTICE file + distributed with this work for additional information + regarding copyright ownership. The ASF licenses this file + to you under the Apache License, Version 2.0 (the + "License"); you may not use this file except in compliance + with the License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, + software distributed under the License is distributed on an + "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + KIND, either express or implied. See the License for the + specific language governing permissions and limitations + under the License. +--> + +# Special Functions + +## Expansion Functiions + +- [unnest](#unnest) +- [unnest(struct)](#unnest-struct) + +### `unnest` + +Expands an array or map into rows. + +#### Arguments + +- **array**: Array expression to unnest. + Can be a constant, column, or function, and any combination of array operators. + +#### Examples + +``` +> select unnest(make_array(1, 2, 3, 4, 5)); ++------------------------------------------------------------------+ +| unnest(make_array(Int64(1),Int64(2),Int64(3),Int64(4),Int64(5))) | ++------------------------------------------------------------------+ +| 1 | +| 2 | +| 3 | +| 4 | +| 5 | ++------------------------------------------------------------------+ +``` + +``` +> select unnest(range(0, 10)); ++-----------------------------------+ +| unnest(range(Int64(0),Int64(10))) | ++-----------------------------------+ +| 0 | +| 1 | +| 2 | +| 3 | +| 4 | +| 5 | +| 6 | +| 7 | +| 8 | +| 9 | ++-----------------------------------+ +``` + +### `unnest (struct)` + +Unwraps struct fields into columns. + +#### Arguments + +- **struct**: Object expression to unnest. + Can be a constant, column, or function, and any combination of object operators. + +#### Examples + +``` +> select * from foo; ++---------------------+ +| column1 | Review Comment: I would rename the column name to struct_field or something. It required for me to look into the example twice to figure our the column1 is actually a structure. Renaming a column will make the example more intuitive -- 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: github-unsubscr...@datafusion.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: github-unsubscr...@datafusion.apache.org For additional commands, e-mail: github-h...@datafusion.apache.org
