SQL Server, just like other relational databases, offers many ways to interact with and manipulate data. Understanding how to retrieve column names from a table is one of the fundamental operations you should be familiar with.
Why Retrieve Column Names?
Before we delve into how to retrieve col names, let’s understand why this is important. When working with databases, especially those with many tables and columns, it’s easy to forget the exact column names or even the data they hold. The ability to retrieve column names helps in:
- Data exploration: You can understand more about the data you’re working with by looking at the column names.
- Dynamic SQL: In some cases, you might need to construct SQL commands dynamically where the column names are not known upfront.
- Data migration: Knowing column names can be critical when moving data between different systems.
How to Retrieve Column Names in SQL Server?
SQL Server provides several ways to retrieve column names. The most common methods leverage system views and stored procedures.
Let’s explore some examples:
Using the INFORMATION_SCHEMA.COLUMNS View
SQL Server has several system views, one of which is INFORMATION_SCHEMA.COLUMNS. You can use it to get column information. Here is an example query:
SELECT * FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = N'YourTableName'
In this query, replace ‘YourTableName’ with the name of your table.
Using the sp_columns Stored Procedure
SQL Server provides a handy stored procedure, sp_columns, which you can use to retrieve column information. Here is how you can use it:
EXEC sp_columns @table_name = 'YourTableName'
Again, replace ‘YourTableName’ with the name of your table.
Using Sys.Columns and Sys.Objects
SQL Server’s sys.columns and sys.objects views can also fetch column information. Here’s an example:
SELECT o.Name TableName, c.Name ColumnName, c.* FROM sys.columns c JOIN sys.objects o ON o.object_id = c.object_id WHERE o.Name = 'PersonPhone' ORDER BY o.Name, c.Name
This query retrieves all columns from all tables, ordered by table and column names.
Conclusion
Retrieving column names in SQL Server is a simple yet crucial task in database management. Whether you’re exploring data, crafting dynamic SQL, or migrating data, these methods will help you navigate your data structure effectively. It demonstrates SQL Server’s power and flexibility in handling data operations. You can connect with me on Twitter.
Reference: Pinal Dave (https://blog.sqlauthority.com)
1 Comment. Leave new
I do something like this. I like to have a row count because if a table is empty it’s basically useless for pulling data. Thanks.
— system search query w/ table counts, change column name or table name wild card to search accordingly
SELECT schema_name(tab.schema_id) as schema_name
, tab.name as table_name
, col.column_id
, col.name as column_name
, t.name as data_type
, col.max_length
, col.precision
, SUM([Partitions].[rows]) AS [TotalRowCount]
FROM sys.tables as tab
JOIN sys.columns as col
ON tab.object_id = col.object_id
LEFT JOIN sys.types as t
ON col.user_type_id = t.user_type_id
JOIN sys.partitions AS [Partitions]
ON tab.[object_id] = [Partitions].[object_id]
AND [Partitions].index_id IN (0,1)
WHERE col.name LIKE ‘%searchterm%’
GROUP BY schema_name(tab.schema_id)
, tab.name
, col.column_id
, col.name
, t.name
, col.max_length
, col.precision
ORDER BY schema_name
, table_name
, column_id