comparing two strings in SQL Server

问题:

Is there any way to compare two strings in SQL Server 2008 stored procedure like below?

int returnval = STRCMP(str1, str2)

• returns 0 if the strings are the same
• returns -1 if the first argument is smaller than the second according to the current sort order.
• returns 1 otherwise.

Above method I find in the MySQL but not in SQL Server.

回答1:

There is no direct string compare function in SQL Server

CASE
  WHEN str1 = str2 THEN 0
  WHEN str1 < str2 THEN -1
  WHEN str1 > str2 THEN 1
  ELSE NULL --one of the strings is NULL so won't compare (added on edit)
END

Notes

• you can wraps this via a UDF using CREATE FUNCTION etc
• you may need NULL handling (in my code above, any NULL will report 1)
• str1 and str2 will be column names or @variables