Querying a SQL Server 2008 table to find values in a column containing Unicode characters

Question

I\'ve run into a problem in a project I\'m working on: some of the string values in a specific SQL Server 2008 table column contain Unicode characters. For example, instead

Answer 1

One way you can do it is to see which rows no longer equal themselves when converted to a datatype that doesn't support unicode.

CREATE TABLE myStrings (
    string nvarchar(max) not null
)

INSERT INTO myStrings (string)
SELECT 'This is not unicode' union all
SELECT 'This has '+nchar(500)+' unicode' union all
SELECT 'This also does not have unicode' union all
SELECT 'This has lots of unicode '+nchar(600)+nchar(700)+nchar(800)+'!'

SELECT cast(string as varchar)
FROM myStrings

SELECT *
FROM myStrings
WHERE cast(cast(string as varchar(max)) as nvarchar(max)) <> string

Answer 2

You want to find all strings that contain one or more characters outside ASCII characters 32-126.

I think this should do the job.

SELECT *
FROM your_table
WHERE your_column LIKE N'%[^ -~]%' collate Latin1_General_BIN

Answer 3

SELECT *
FROM your_table
WHERE your_column LIKE N'%[^ -~]%' collate Latin1_General_BIN

finds all strings that contain one or more characters within ASCII characters 32-126.

I thought the purpose was to find strings where ASCII characters are not in the range 32-126?

NOT is possible with LIKE. Wouldn't this work?

SELECT *
FROM your_table
WHERE your_column NOT LIKE N'%[^ -~]%'

No collate required.