--- sidebar_position: 46 sidebar_label: input --- # input `input(structure)` - table function that allows effectively convert and insert data sent to the server with given structure to the table with another structure. `structure` - structure of data sent to the server in following format `'column1_name column1_type, column2_name column2_type, ...'`. For example, `'id UInt32, name String'`. This function can be used only in `INSERT SELECT` query and only once but otherwise behaves like ordinary table function (for example, it can be used in subquery, etc.). Data can be sent in any way like for ordinary `INSERT` query and passed in any available [format](../../interfaces/formats.md#formats) that must be specified in the end of query (unlike ordinary `INSERT SELECT`). The main feature of this function is that when server receives data from client it simultaneously converts it according to the list of expressions in the `SELECT` clause and inserts into the target table. Temporary table with all transferred data is not created. **Examples** - Let the `test` table has the following structure `(a String, b String)` and data in `data.csv` has a different structure `(col1 String, col2 Date, col3 Int32)`. Query for insert data from the `data.csv` into the `test` table with simultaneous conversion looks like this: ``` bash $ cat data.csv | clickhouse-client --query="INSERT INTO test SELECT lower(col1), col3 * col3 FROM input('col1 String, col2 Date, col3 Int32') FORMAT CSV"; ``` - If `data.csv` contains data of the same structure `test_structure` as the table `test` then these two queries are equal: ``` bash $ cat data.csv | clickhouse-client --query="INSERT INTO test FORMAT CSV" $ cat data.csv | clickhouse-client --query="INSERT INTO test SELECT * FROM input('test_structure') FORMAT CSV" ```