Merge pull request #16534 from olgarev/revolg-DOCSUP-3043-document_the_null_function

DOCSUP-3043: Documented the null function

docs/en/sql-reference/table-functions/null.md

@@ -0,0 +1,41 @@
+---
+toc_priority: 53
+toc_title: null function
+---
+
+# null {#null-function}
+
+Accepts an inserted data of the specified structure and immediately drops it away. The function is used for convenience writing tests and demonstrations.
+
+**Syntax** 
+
+``` sql
+null('structure')
+```
+
+**Parameter** 
+
+-   `structure` — A list of columns and column types. [String](../../sql-reference/data-types/string.md).
+
+**Returned value**
+
+A table with the specified structure, which is dropped right after the query execution.
+
+**Example**
+
+Query with the `null` function:
+
+``` sql
+INSERT INTO function null('x UInt64') SELECT * FROM numbers_mt(1000000000);
+```
+can replace three queries:
+
+```sql
+CREATE TABLE t (x UInt64) ENGINE = Null;
+INSERT INTO t SELECT * FROM numbers_mt(1000000000);
+DROP TABLE IF EXISTS t;
+```
+
+See also: format **Null**.
+
+[Original article](https://clickhouse.tech/docs/en/sql-reference/table-functions/null/) <!--hide-->