SQL Substring Extraction

I am trying to set two substring values, from an audit table, to respective columns but the solutions I've found pertain more to single character delimiters than substring delimiters. Any guidance and/or suggestions would be great as there are around 30 unique statuses and hundreds of 'from --> to' combinations of statuses.

What I have now (from the audit.audit_text field):

Ticket status has been changed from "In Progress" to "Ready for Dispatch".
Escalation level changed from "Plan" to "Waiting"


Here is what I've tried:

 SUBSTRING(dbo.SR_Audit.Audit_Text, CHARINDEX('to ', dbo.SR_Audit.Audit_Text) + 4, CHARINDEX('. ', dbo.SR_Audit.Audit_Text) - CHARINDEX('to',dbo.SR_Audit.Audit_Text) - 5) AS ChangedTo,

SUBSTRING(dbo.SR_Audit.Audit_Text, CHARINDEX('from ', dbo.SR_Audit.Audit_Text) + 6, CHARINDEX('to ',
                         dbo.SR_Audit.Audit_Text) - CHARINDEX('from', dbo.SR_Audit.Audit_Text) - 8) AS ChangedFrom


-----------------
(See attached results)
The ChangedFrom field seems to be OK but the ChangedTo field has some unwanted results.
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I want to strip the quote marks that surround each status and ignore everything after the first sentence.

Desired alias fields:

Alias                Value
ChangedFrom    In Progress
ChangedTo         Ready for Dispatch
Results1.PNG
Ben RapierAsked:
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Scott PletcherSenior DBACommented:
Can't write any code against a picture of data.  Without actual INSERT statements with data, can only  guess at the code.
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ste5anSenior DeveloperCommented:
When your audit text is well-formed as shown above:

DECLARE @Sample TABLE
    (
      AuditText NVARCHAR(MAX)
    );

INSERT  INTO @Sample
VALUES  ( N'Ticket status has been changed from "In Progress" to "Ready for Dispatch".' ),
        ( N'Escalation level changed from "Plan" to "Waiting"' );

WITH    Data
          AS ( SELECT   S.AuditText ,
                        CAST(REPLACE(REPLACE(S.AuditText, ' "', '<s>'), '"', '</s>') AS XML) AS AuditTextXml
               FROM     @Sample S
             )
    SELECT  D.AuditText ,
            FromStatus.value('.', 'NVARCHAR(255)') AS FromStatus ,
            ToStatus.value('.', 'NVARCHAR(255)') AS ToStatus
    FROM    Data D
            CROSS APPLY D.AuditTextXml.nodes('//s[1]') S1 ( FromStatus )
            CROSS APPLY D.AuditTextXml.nodes('//s[2]') S2 ( ToStatus );

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Scott PletcherSenior DBACommented:
I try to allow as many variances as possible.  I also push down the complex string manipulation to a step-by-step process in cross applys, to simply the main SELECT and to better debug.  For example:


select audit_text, ChangedFrom, ChangedTo
from ( --dbo.SR_Audit sa
    select 'Ticket status has been changed from "In Progress" to "Ready for Dispatch".' as audit_text union all
    select 'Escalation level changed from "Plan" to "Waiting"' UNION ALL
    select 'Whatever changed from "abc"def to "fgi,jkl.' UNION ALL
    select 'changed from "something" but that''s all no t=o string match' UNION ALL
    select 'changed from abc to xyz'
) as  sa --sample data
cross apply (
    select patindex('%[^a-z]to %',  sa.Audit_Text) as to_start
) as assign_alias_names1
cross apply (
    select patindex('%[^a-z]from %', sa.Audit_Text) as from_start
) as assign_alias_names2
cross apply (
    select case when from_start < to_start and to_start > 0 and from_start > 0 then 1 else 0 end as change_found
) as assign_alias_names3
cross apply (
    select (to_start - 1) - (from_start + 6) + 1 as from_length,
        charindex('.', sa.Audit_Text + '.', to_start + 5) - to_start - 4 as to_length
) as assign_alias_names4
cross apply (
    select
        case when change_found = 0 then '' else substring(sa.Audit_Text, from_start + 6, from_length) end as changed_from_raw,
        case when change_found = 0 then '' else substring(sa.Audit_Text, to_start + 4, to_length) end as changed_to_raw
) as assign_alias_names5
cross apply (
    select
        case when change_found = 0 then '' else
            case when left(changed_from_raw, 1) = '"' then '' else left(changed_from_raw, 1) end +
                substring(changed_from_raw, 2, len(changed_from_raw) - 1 -
                case when right(changed_from_raw, 1) = '"' then 1 else 0 end) end as ChangedFrom,
        case when change_found = 0 then '' else
            case when left(changed_to_raw, 1) = '"' then '' else left(changed_to_raw, 1) end +
                substring(changed_to_raw, 2, len(changed_to_raw) - 1 -
                case when right(changed_to_raw, 1) = '"' then 1 else 0 end) end as ChangedTo
) as assign_alias_names6
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Ben RapierAuthor Commented:
Thanks for the quick answers!
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Microsoft SQL Server 2008

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