difference

Returns the difference between two soundex values.

Syntax

difference(expr1,expr2)

expr1 – is a character-type column name, variable, or constant expression of char, varchar, nchar, nvarchar, or unichar type.
expr2 – is another character-type column name, variable, or constant expression of char, varchar, nchar, nvarchar, or unichar type.

Example 1 – Returns the difference between "smithers" and "smothers":
```
select difference("smithers", "smothers")
```
```
---------
4
```
Example 2 – Returns the difference between "smothers" and "brothers":
```
select difference("smothers", "brothers")
```
```
---------
2
```

difference, a string function, returns an integer representing the difference between two soundex values.
The difference function compares two strings and evaluates the similarity between them, returning a value from 0 to 4. The best match is 4.

The string values must be composed of a contiguous sequence of valid single- or double-byte roman letters.
If expr1 or expr2 is NULL, returns NULL.
If you give a varchar expression is given as one parameter and a unichar expression as the other, the varchar expression is implicitly converted to unichar (with possible truncation).

ANSI SQL – Compliance level: Transact-SQL extension.

Any user can execute difference.