Answers.Body: <p>Try doing a Contact import just of Civi ID, and new External ID, and set it to Update using a matching rule based on civi id.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2021-12-09T03:46:28.607Z
Answers.LastActivityDate: 2021-12-09T03:46:28.607Z
Answers.UserDisplayName: petednz - fuzion
Body: <p>My client's outside database has changed. I have spent a few hours (fun!) matching the old and new external IDs and the internal CiviCRM contact ID as well. Not every record in the CiviCRM database has or will have an external ID.</p>
  <p>I will probably need to do an update using SQL (mySQL/phpmySQL), but I'm a little uncertain that that's the best way and I don't want to break the entire database!</p>
  <p>The current data is in Excel: CiviCRM ID, New ExternalID, old ExternalID.</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-11-24T01:07:42.510Z
Comments.Text: does doing a Contact import just of Civi ID, and new External ID, not work? using a matching rule based on civi id
Comments.UserDisplayName: petednz - fuzion
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-12-07T17:23:22.000Z
Comments.Text: Thank you. You were correct and it was easy. For some reason I thought I ran into problems in the past. (Must choose "update" of course.) I limited the import to these two fields.
Comments.UserDisplayName: TimETown
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-12-09T03:46:46.977Z
Comments.Text: cool. added as an Answer, pls Accept
Comments.UserDisplayName: petednz - fuzion
Tags: <mysql><external-id>
Title: How can I update all my external-IDs?
ThreadText: # How can I update all my external-IDs?
  
  (Asked by: username_0 on 2021-11-23)
  
  My client's outside database has changed. I have spent a few hours (fun!) matching the old and new external IDs and the internal CiviCRM contact ID as well. Not every record in the CiviCRM database has or will have an external ID.
  
  I will probably need to do an update using SQL (mySQL/phpmySQL), but I'm a little uncertain that that's the best way and I don't want to break the entire database!
  
  The current data is in Excel: CiviCRM ID, New ExternalID, old ExternalID.
  
  **Tags:** mysql, external-id
  
  > **Comments:**
  > **username_1**: does doing a Contact import just of Civi ID, and new External ID, not work? using a matching rule based on civi id  
  > **username_0**: Thank you. You were correct and it was easy. For some reason I thought I ran into problems in the past. (Must choose "update" of course.) I limited the import to these two fields.  
  > **username_1**: cool. added as an Answer, pls Accept  
  
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  ## 1 answers
  
  ### Answer by username_1 on 2021-12-09. Score: 1
  
  Try doing a Contact import just of Civi ID, and new External ID, and set it to Update using a matching rule based on civi id.
  
  
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