---
title: "Delete Columns from a Table | Microsoft Docs"
ms.custom: ""
ms.date: "04/11/2017"
ms.prod: sql
ms.prod_service: "table-view-index, sql-database, sql-data-warehouse, pdw"
ms.reviewer: ""
ms.technology: table-view-index
ms.topic: conceptual
helpviewer_keywords: 
  - "columns [SQL Server], deleting"
  - "removing columns"
  - "deleting columns"
  - "dropping columns"
ms.assetid: 0d8f6e4f-bc71-4fa3-8615-74249c8e072d
author: stevestein
ms.author: sstein
monikerRange: ">=aps-pdw-2016||=azuresqldb-current||=azure-sqldw-latest||>=sql-server-2016||=sqlallproducts-allversions||>=sql-server-linux-2017||=azuresqldb-mi-current"
---
# Delete Columns from a Table

[!INCLUDE[tsql-appliesto-ss2016-all-md](../../includes/tsql-appliesto-ss2016-all-md.md)]

This topic describes how to delete table columns in [!INCLUDE[ssCurrent](../../includes/sscurrent-md.md)] by using [!INCLUDE[ssManStudioFull](../../includes/ssmanstudiofull-md.md)] or [!INCLUDE[tsql](../../includes/tsql-md.md)].

> [!CAUTION]
> When you delete a column from a table, it and all the data it contains are deleted.

 **In This Topic**

- **Before you begin:**

   [Limitations and Restrictions](#Restrictions)

   [Security](#Security)

- **To delete a column from a table, using:**

   [SQL Server Management Studio](#SSMSProcedure)

   [Transact-SQL](#TsqlProcedure)

## <a name="BeforeYouBegin"></a> Before You Begin

### <a name="Restrictions"></a> Limitations and Restrictions

You cannot delete a column that has a CHECK constraint. You must first delete the constraint.

You cannot delete a column that has PRIMARY KEY or FOREIGN KEY constraints or other dependencies except when using the Table Designer. When using Object Explorer or [!INCLUDE[tsql](../../includes/tsql-md.md)], you must first remove all dependencies on the column.

### <a name="Security"></a> Security

#### <a name="Permissions"></a> Permissions

Requires ALTER permission on the table.

## <a name="SSMSProcedure"></a> Using SQL Server Management Studio

### To delete columns by using Object Explorer

1. In **Object Explorer**, connect to an instance of [!INCLUDE[ssDE](../../includes/ssde-md.md)].
2. In **Object Explorer**, locate the table from which you want to delete columns, and expand to expose the column names.
3. Right-click the column that you want to delete, and choose **Delete**.
4. In **Delete Object** dialog box, click **OK**.

If the column contains constraints or other dependencies, an error message will display in the **Delete Object** dialog box. Resolve the error by deleting the referenced constraints.

### To delete columns by using Table Designer

1. In **Object Explorer**, right-click the table from which you want to delete columns and choose **Design**.
2. Right-click the column you want to delete and choose **Delete Column** from the shortcut menu.
3. If the column participates in a relationship (FOREIGN KEY or PRIMARY KEY), a message prompts you to confirm the deletion of the selected columns and their relationships. Choose **Yes**.

## <a name="TsqlProcedure"></a> Using Transact-SQL

### To delete columns

The following example shows you how to delete a column.

```sql
ALTER TABLE dbo.doc_exb DROP COLUMN column_b;
```

If the column contains constraints or other dependencies, an error message will be returned. Resolve the error by deleting the referenced constraints.

For additional examples, see [ALTER TABLE &#40;Transact-SQL&#41;](../../t-sql/statements/alter-table-transact-sql.md).

## <a name="FollowUp"></a>