---
title: "_ (Wildcard - Match One Character) (Transact-SQL) | Microsoft Docs"
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  - "Match One"
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---
# _ (Wildcard - Match One Character) (Transact-SQL)
[!INCLUDE[tsql-appliesto-ss2008-asdb-xxxx-xxx_md](../../includes/tsql-appliesto-ss2008-asdb-xxxx-xxx-md.md)]

  Use the underscore character `_` to match any single character in a string comparison operation that involves pattern matching, such as `LIKE` and `PATINDEX`.  
  
## Examples  

## A: Simple example   

The following example returns all database names that begin with the letter `m` and have the letter `d` as the third letter. The underscore character specifies that the second character of the name can be any letter. The `model` and `msdb` databases meet this criteria. The `master` database does not.

```tsql
SELECT name FROM sys.databases
WHERE name LIKE 'm_d%';
```   
[!INCLUDE[ssResult_md](../../includes/ssresult-md.md)]   
```
name
-----
model
msdb
```   
You may have additional databases that meet this criteria.

You can use multiple underscores to represent multiple characters. Changing the `LIKE` criteria to include two underscores `'m__%` includes the master database in the result.

### B: More complex example
 The following example uses the `_` operator to find all the people in the `Person` table, who have a three-letter first name that ends in `an`.  
  
```tsql  
-- Uses AdventureWorks  
  
SELECT FirstName, LastName  
FROM Person.Person  
WHERE FirstName LIKE '_an'  
ORDER BY FirstName;  
```  
## C: Escaping the underscore character   
The following example returns the names of the fixed database roles like `db_owner` and `db_ddladmin`, but it also returns the `dbo` user. 

```tsql
SELECT name FROM sys.database_principals
WHERE name LIKE 'db_%';
```

The underscore in the third character position is taken as a wildcard, and is not filtering for only principals starting with the letters `db_`. To escape the underscore enclose it in brackets `[_]`. 

```tsql
SELECT name FROM sys.database_principals
WHERE name LIKE 'db[_]%';
```   
Now the `dbo` user is excluded.   
[!INCLUDE[ssResult_md](../../includes/ssresult-md.md)]   
```
name
-------------
db_owner
db_accessadmin
db_securityadmin
...
```

  
## See Also  
 [LIKE (Transact-SQL)](../../t-sql/language-elements/like-transact-sql.md)   
 [PATINDEX (Transact-SQL)](../../t-sql/functions/patindex-transact-sql.md)   
  [% (Wildcard - Character(s) to Match)](../../t-sql/language-elements/percent-character-wildcard-character-s-to-match-transact-sql.md)   
  [[ ] (Wildcard - Character(s) to Match)](../../t-sql/language-elements/wildcard-character-s-to-match-transact-sql.md)   
 [[^] (Wildcard - Character(s) Not to Match)](../../t-sql/language-elements/wildcard-character-s-not-to-match-transact-sql.md)