Trim spaces in string - LTRIM RTRIM not working

Question

I tried this code -

UPDATE Table
SET Name = RTRIM(LTRIM(Name))

Data type of Name is varchar(25)

None of the leading and t

Answer 1

If your string has some non-unicode chars, then those need to be removed first. The functions for that are given later, taken from this link - http://iso30-sql.blogspot.com/2010/10/remove-non-printable-unicode-characters.html

First, check if there are any weird hex chars using -

select convert(varbinary, Name) from table

Then, use the code given in the link above. Note that in the usage of functions, square brackets are to be removed, otherwise the code won't work. Eg. [@DatabaseName = 'MyDatabaseName',] [@SchemaName = 'MySchemaName',]

After this, your strings might have some spaces which can be removed using -

UPDATE Table
SET Name = RTRIM(LTRIM(Name))

Also NOTE that the scripts given in the above link/below will not work on the following table -

CREATE TABLE [dbo].[Junk](
    [JunkHex] nvarchar(50) NULL
) ON [PRIMARY]
GO

GO
INSERT [dbo].[Junk] ([JunkHex]) VALUES (N'Stringğ ')
INSERT [dbo].[Junk] ([JunkHex]) VALUES (N'withħ')
INSERT [dbo].[Junk] ([JunkHex]) VALUES (N'įņvalidđ')
INSERT [dbo].[Junk] ([JunkHex]) VALUES (N'charactersŝ')

---

This is the content of the link I have given above -

Remove non-printable / Unicode characters in SQL Server 2005 A few months ago, I was upgrading some report templates from the older version of Excel (.xls) to Excel 2007 (.xlsx). I ran into numerous problems almost immediately when I attempted to generate the upgraded reports because the incoming data was riddled with charaters that don't play nicely with XML. The data is used for a variety of reporting purposes, so I decided to tackle the problem on the back-end by removing all but the printable ascii characters.

I started by writing a simple user function for individual strings, but I got to thinking that I may want to automate some of these cleanup tasks and ended up putting something together that allows for a bit more the flexibility. The following creates the basic string user function, along with two procedures to perform the cleanup at the column and table level:

Note - Each of the scripts below uses all the ones above it. So, execute all scripts in order to get all functionality.

Function: fn_npclean_string

use [master]
go
set ansi_nulls on
go
set quoted_identifier on
go
CREATE function [dbo].[fn_npclean_string] (
 @strIn as varchar(1000)
)
returns varchar(1000)
as
begin
 declare @iPtr as int
 set @iPtr = patindex('%[^ -~0-9A-Z]%', @strIn COLLATE LATIN1_GENERAL_BIN)
 while @iPtr > 0 begin
  set @strIn = replace(@strIn COLLATE LATIN1_GENERAL_BIN, substring(@strIn, @iPtr, 1), '')
  set @iPtr = patindex('%[^ -~0-9A-Z]%', @strIn COLLATE LATIN1_GENERAL_BIN)
 end
 return @strIn
end

Procedure: sp_npclean_col

use [master]
go
set ansi_nulls on
go
set quoted_identifier on
go
CREATE procedure [dbo].[sp_npclean_col]
 @DatabaseName varchar(75) = null,
 @SchemaName varchar(75) = null,
 @TableName varchar(75),
 @ColumnName varchar(75)
as
begin
 Declare @FullTableName varchar(100)
 declare @UpdateSQL nvarchar(1000)
 if @DatabaseName is null begin
  set @DatabaseName = db_name()
 end
 if @SchemaName is null begin
  set @SchemaName = schema_name()
 end
 set @FullTableName = '[' + @DatabaseName + '].[' + @SchemaName + '].[' + @TableName + ']'
 set @UpdateSQL = 'update ' + @FullTableName + ' set [' + @ColumnName + '] = dbo.fn_npclean_string([' + @ColumnName + ']) where [' + @ColumnName + '] like ''%[^ -~0-9A-Z]%'''
 exec sp_ExecuteSQL @UpdateSQL
end

Procedure: sp_npclean_table

use [master]
go
set ansi_nulls on
go
set quoted_identifier on
go
create procedure [dbo].[sp_npclean_table] 
 @TargetDatabase varchar(75) = null,
 @TargetSchema varchar(75) = null,
 @TargetTable varchar(75)
as
begin
 declare @getColSQL nvarchar(750)
 declare @textCol CURSOR
 declare @curCol varchar(75)
 if @TargetDatabase is null begin
  set @TargetDatabase = db_name()
 end
 if @TargetSchema is null begin
  set @TargetSchema = schema_name()
 end
 set @getColSQL =
  'select sc.name
  from ' + @TargetDatabase + '.sys.columns sc
  join ' + @TargetDatabase + '.sys.types st
  on sc.system_type_id = st.system_type_id
  join ' + @TargetDatabase + '.sys.objects so
  on sc.object_id = so.object_id
  join ' + @TargetDatabase + '.sys.schemas ss
  on so.schema_id = ss.schema_id
  where
  so.type = ''U''
  and st.name in (''text'',''ntext'',''varchar'',''char'',''nvarchar'',''nchar'')
  and sc.is_rowguidcol = 0
  and sc.is_identity = 0
  and sc.is_computed = 0
  and so.name = ''' + @TargetTable + '''
  and ss.name = ''' + @TargetSchema + ''''
 set @getColSQL = 'set @inCursor = cursor for ' + @getColSQL + ' open @incursor'
 execute sp_executesql @getColSQL,N'@inCursor cursor out',@inCursor=@textCol OUT
 fetch next from @textCol into @curCol
 while @@fetch_status = 0
 begin
  exec sp_npclean_col @DatabaseName = @TargetDatabase, @SchemaName = @TargetSchema, @TableName = @TargetTable, @ColumnName = @curCol
  fetch next from @textCol into @curCol
 end
 Close @textCol
 DeAllocate @textCol
end

Using these, invalid characters can be removed in the following ways:

By String:

select master.dbo.fn_npclean_string('Stringğ withħ įņvalidđ charactersŝ')

By table column:

exec master.dbo.sp_npclean_col [@DatabaseName = 'MyDatabaseName',] [@SchemaName = 'MySchemaName',] @TableName = 'MyTableName',  @ColumnName = 'MyColumnName'

By table:

exec master.dbo.sp_npclean_table [@TargetDatabase = 'MyDatabaseName',] [@TargetSchema = 'MySchemaName',] @TargetTable = 'MyTableName'