---
metadata:
  - name: generator
    content: Diplodoc Platform v5.52.0
alternate:
  - https://ydb.tech/docs/en/yql/reference/syntax/alter_table/columns.md?version=v25.3
  - https://ydb.tech/docs/ru/yql/reference/syntax/alter_table/columns.md?version=v25.3
  - href: en/yql/reference/syntax/alter_table/columns.md
    type: text/markdown
    title: Markdown version
  - href: ../../../../llms.txt
    type: text/markdown
    title: llms.txt
sourcePath: en/core/yql/reference/syntax/alter_table/columns.md
---
> **Documentation Index:** Fetch the complete configuration index at https://ydb.tech/docs/en/llms.txt

# Changing the composition of columns

YDB supports adding columns to  [row](https://ydb.tech/docs/en/concepts/datamodel/table.md?version=v25.3#row-oriented-tables) and [column](https://ydb.tech/docs/en/concepts/datamodel/table.md?version=v25.3#column-oriented-tables) tables, as well as deleting non-key columns from tables.

`ADD COLUMN` — adds a column with the specified name and type. The code below will add a column named `views` with data type `Uint64` to the `episodes` table.

```yql
ALTER TABLE episodes ADD COLUMN views Uint64;
```

`DROP COLUMN` — deletes a column with the specified name. The code below will delete the column named `views` from the `episodes` table.

```yql
ALTER TABLE episodes DROP COLUMN views;
```