Ok, I know I answered this before, but it bugged me that we couldn't write something efficient to handle an unknown amount of 'text segments'.
So re-thinking it and researching, I discovered a way to change the [MAILCITY] field into XML nodes where each 'text segment' is assigned it's own Node within the xml field. Then those xml fields can be processed node by node, concatenated together, and then changed back to a SQL varchar. It's convoluted, but it works. :)
Here's the code:
CREATE TABLE
#masterfeelisting (
[MAILCITY] varchar(max) not null
);
INSERT INTO #masterfeelisting VALUES
('terra bellA')
,(' terrA novA ')
,('chicagO ')
,('bostoN')
,('porT dE sanTo')
,(' porT dE sanTo pallo ');
SELECT
RTRIM
(
(SELECT
UPPER([xmlField].[xmlNode].value('.', 'char(1)')) +
LOWER(STUFF([xmlField].[xmlNode].value('.', 'varchar(max)'), 1, 1, '')) + ' '
FROM [xmlNodeRecordSet].[nodeField].nodes('/N') as [xmlField]([xmlNode]) FOR
xml path(''), type
).value('.', 'varchar(max)')
) as [MAILCITY]
FROM
(SELECT
CAST('<N>' + REPLACE([MAILCITY],' ','</N><N>')+'</N>' as xml) as [nodeField]
FROM #masterfeelisting
) as [xmlNodeRecordSet];
Drop table #masterfeelisting;
First I create a table and fill it with dummy values.
Now here is the beauty of the code:
For each record in #masterfeelisting, we are going to create an xml field with a node for each 'text segment'.
ie. '<N></N><N>terrA</N><N>novA</N><N></N>'
(This is built from the varchar ' terrA novA ')
1) The way this is done is by using the REPLACE function.
The string starts with a '<N>'
to designate the beginning of the node. Then:
REPLACE([MAILCITY],' ','</N><N>')
This effectively goes through the whole [MAILCITY] string and replaces each
' '
with '</N><N>'
and then the string ends with a '</N>'
. Where '</N>'
designates the end of each node.
So now we have a beautiful XML string with a couple of empty nodes and the 'text segments' nicely nestled in their own node. All the 'spaces' have been removed.
2) Then we have to CAST the string into xml. And we will name that field [nodeField]. Now we can use xml functions on our newly created record set. (Conveniently named [xmlNodeRecordSet].)
3) Now we can read the [xmlNodeRecordSet] into the main sub-Select by stating:
FROM [xmlNodeRecordSet].[nodeField].nodes('/N')
This tells us we are reading the [nodeField] as nodes with a '/N'
delimiter.
This table of node fields is then parsed by stating:
as [xmlField]([xmlNode]) FOR xml path(''), type
This means each [xmlField] will be parsed for each [xmlNode] in the xml string.
4) So in the main sub-select:
Each blank node '<N></N>'
is discarded. (Or not processed.)
Each node with a 'text segment' in it will be parsed. ie <N>terrA</N>
UPPER([xmlField].[xmlNode].value('.', 'char(1)')) +
This code will grab each node out of the field and take its contents '.'
and only grab the first character 'char(1)'
. Then it will Upper case that character. (the plus sign at the end means it will concatenate this letter with the next bit of code:
LOWER(STUFF([xmlField].[xmlNode].value('.', 'varchar(max)'), 1, 1, ''))
Now here is the beauty... STUFF is a function that will take a string, from a position, for a length, and substitute another string.
STUFF(string, start position, length, replacement string)
So our string is:
[xmlField].[xmlNode].value('.', 'varchar(max)')
Which grabs the whole string inside the current node since it is 'varchar(max)'
.
The start position is 1. The length is 1. And the replacement string is ''
. This effectively strips off the first character by replacing it with nothing. So the remaining string is all the other characters that we want to have lower case. So that's what we do... we use LOWER
to make them all lower case. And this result is concatenated to our first letter that we already upper cased.
But wait... we are not done yet... we still have to append a + ' '
. Which adds a blank space after our nicely capitalized 'text segment'. Just in case there is another 'text segment' after this node is done.
This main sub-Select will now parse each node in our [xmlField] and concatenate them all nicely together.
5) But now that we have one big happy concatenation, we still have to change it back from an xml field to a SQL varchar field. So after the main sub-select we need:
.value('.', 'varchar(max)')
This changes our [MAILCITY] back to a SQL varchar.
6) But hold on... we still are not done. Remember we put an extra space at the end of each 'text segment'??? Well the last 'text segment still has that extra space after it. So we need to Right Trim that space off by using RTRIM
.
7) And dont forget to rename the final field back to as [MAILCITY]
8) And that's it. This code will take an unknown amount of 'text segments' and format each one of them. All using the fun of XML and it's node parsers.
Hope that helps :)