In SQL Server, you can use the SCHEMA_NAME() function to return the name of a particular schema. The way it works is that it returns the schema name associated with a schema ID.

If you don’t pass a schema ID to the function, it returns the name of the default schema of the caller.

Example 1 – Return Default Schema

Here’s an example that returns the name of the default schema of the caller.

SELECT SCHEMA_NAME() AS Result;

Result:

+----------+
| Result   |
|----------|
| dbo      |
+----------+

This returns the name of the default schema of the caller because I didn’t explicitly specify another schema ID.

Example 2 – Specify a Different Schema

In this example I pass a schema ID to the function.

SELECT SCHEMA_NAME(7) AS Result;

Result:

+----------+
| Result   |
|----------|
| Fact     |
+----------+

Example 3 – Switching Databases

The previous example just happened to be run in a database that had a schema with an ID of 7. If I switch to a different database, I might get a different schema name, or no name at all.

Here’s an example of what I mean.

USE WideWorldImportersDW;
SELECT 
  SCHEMA_NAME(1) AS [1],
  SCHEMA_NAME(2) AS [2],
  SCHEMA_NAME(3) AS [3],
  SCHEMA_NAME(4) AS [4],
  SCHEMA_NAME(5) AS [5],
  SCHEMA_NAME(6) AS [6],
  SCHEMA_NAME(7) AS [7],
  SCHEMA_NAME(8) AS [8];

USE Music;
SELECT 
  SCHEMA_NAME(1) AS [1],
  SCHEMA_NAME(2) AS [2],
  SCHEMA_NAME(3) AS [3],
  SCHEMA_NAME(4) AS [4],
  SCHEMA_NAME(5) AS [5],
  SCHEMA_NAME(6) AS [6],
  SCHEMA_NAME(7) AS [7],
  SCHEMA_NAME(8) AS [8]; 

Result:

Changed database context to 'WideWorldImportersDW'.
+-----+-------+--------------------+-----+-------------+-----------+------+-------------+
| 1   | 2     | 3                  | 4   | 5           | 6         | 7    | 8           |
|-----+-------+--------------------+-----+-------------+-----------+------+-------------|
| dbo | guest | INFORMATION_SCHEMA | sys | Application | Dimension | Fact | Integration |
+-----+-------+--------------------+-----+-------------+-----------+------+-------------+
(1 row affected)
Changed database context to 'Music'.
+-----+-------+--------------------+-----+------+------+------+------+
| 1   | 2     | 3                  | 4   | 5    | 6    | 7    | 8    |
|-----+-------+--------------------+-----+------+------+------+------|
| dbo | guest | INFORMATION_SCHEMA | sys | NULL | NULL | NULL | NULL |
+-----+-------+--------------------+-----+------+------+------+------+
(1 row affected)

Four columns return NULL on the Music database, because there’s no schema with that ID.

Example 4 – More Readable Query Results

Here’s an example of using SCHEMA_NAME() to present the schema name instead of its ID when returning results from a system view.

SELECT 
  schema_id,
  SCHEMA_NAME(schema_id) AS [Schema Name],
  name AS [Table Name]
FROM sys.tables;

Result:

+-------------+---------------+-------------------------+
| schema_id   | Schema Name   | Table Name              |
|-------------+---------------+-------------------------|
| 8           | Integration   | ETL Cutoff              |
| 8           | Integration   | Lineage                 |
| 8           | Integration   | Customer_Staging        |
| 8           | Integration   | Employee_Staging        |
| 8           | Integration   | Movement_Staging        |
| 8           | Integration   | Order_Staging           |
| 8           | Integration   | PaymentMethod_Staging   |
| 6           | Dimension     | City                    |
| 8           | Integration   | Purchase_Staging        |
| 6           | Dimension     | Customer                |
| 8           | Integration   | Sale_Staging            |
| 8           | Integration   | StockHolding_Staging    |
| 6           | Dimension     | Date                    |
| 8           | Integration   | StockItem_Staging       |
| 6           | Dimension     | Employee                |
| 8           | Integration   | Supplier_Staging        |
| 6           | Dimension     | Payment Method          |
| 8           | Integration   | Transaction_Staging     |
| 8           | Integration   | TransactionType_Staging |
| 6           | Dimension     | Stock Item              |
| 6           | Dimension     | Supplier                |
| 6           | Dimension     | Transaction Type        |
| 7           | Fact          | Movement                |
| 7           | Fact          | Order                   |
| 7           | Fact          | Purchase                |
| 7           | Fact          | Sale                    |
| 7           | Fact          | Stock Holding           |
| 7           | Fact          | Transaction             |
| 8           | Integration   | City_Staging            |
+-------------+---------------+-------------------------+

The sys.tables system view returns the schema ID but not its name. That’s not a problem though. The ID is sufficient, because we can use SCHEMA_NAME() to display the schema’s name, based on that ID.

If we didn’t have the SCHEMA_NAME() function, we’d need to do a join on the sys.schemas system view just to get the schema’s name.

Example 5 – In a WHERE Clause

Here’s an example of using SCHEMA_NAME() in a WHERE clause.

USE WideWorldImportersDW;
SELECT * FROM sys.schemas
WHERE name = SCHEMA_NAME(7);

Result:

+--------+-------------+----------------+
| name   | schema_id   | principal_id   |
|--------+-------------+----------------|
| Fact   | 7           | 1              |
+--------+-------------+----------------+

If you need to get a schema’s ID, use the SCHEMA_ID() function.