Skip to content

Instantly share code, notes, and snippets.

@tulanght

tulanght/README.md

Forked from magnetikonline/README.md
Created April 16, 2014 09:59
Download ZIP

Revisions

  1. Peter Mescalchin revised this gist Apr 14, 2014. 1 changed file with 3 additions and 3 deletions.
    6 changes: 3 additions & 3 deletions README.md
    View file
    Original file line number Diff line number Diff line change
    @@ -99,22 +99,22 @@ HAVING (COUNT(*) > 1)
    ```

    ### wp_postmeta missing
    Checking for missing `_wp_attached_file` / `_wp_attachment_metadata` keys on `wp_posts.post_type = 'Attachment'` rows.
    Checking for missing `_wp_attached_file` / `_wp_attachment_metadata` keys on `wp_posts.post_type = 'attachment'` rows.

    ```sql
    SELECT * FROM wp_posts
    LEFT JOIN wp_postmeta ON (
    (wp_posts.ID = wp_postmeta.post_id) AND
    (wp_postmeta.meta_key = '_wp_attached_file')
    )
    WHERE (wp_posts.post_type = 'Attachment') AND (wp_postmeta.meta_id IS NULL)
    WHERE (wp_posts.post_type = 'attachment') AND (wp_postmeta.meta_id IS NULL)

    SELECT * FROM wp_posts
    LEFT JOIN wp_postmeta ON (
    (wp_posts.ID = wp_postmeta.post_id) AND
    (wp_postmeta.meta_key = '_wp_attachment_metadata')
    )
    WHERE (wp_posts.post_type = 'Attachment') AND (wp_postmeta.meta_id IS NULL)
    WHERE (wp_posts.post_type = 'attachment') AND (wp_postmeta.meta_id IS NULL)
    ```

    ### wp_options '_transient_' rows
  2. Peter Mescalchin created this gist Apr 13, 2014.
    126 changes: 126 additions & 0 deletions README.md
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,126 @@
    # WordPress database clean up queries

    ## Orphan rows
    Since WordPress uses MyISAM for it's storage engine, we don't get foreign keys - thus orphan rows can show themselves.

    ### wp_posts -> wp_posts (parent/child)

    ```sql
    SELECT * FROM wp_posts
    LEFT JOIN wp_posts child ON (wp_posts.post_parent = child.ID)
    WHERE (wp_posts.post_parent <> 0) AND (child.ID IS NULL)

    DELETE wp_posts FROM wp_posts
    LEFT JOIN wp_posts child ON (wp_posts.post_parent = child.ID)
    WHERE (wp_posts.post_parent <> 0) AND (child.ID IS NULL)
    ```

    ### wp_postmeta -> wp_posts

    ```sql
    SELECT * FROM wp_postmeta
    LEFT JOIN wp_posts ON (wp_postmeta.post_id = wp_posts.ID)
    WHERE (wp_posts.ID IS NULL)

    DELETE wp_postmeta FROM wp_postmeta
    LEFT JOIN wp_posts ON (wp_postmeta.post_id = wp_posts.ID)
    WHERE (wp_posts.ID IS NULL)
    ```

    ### wp_term_taxonomy -> wp_terms

    ```sql
    SELECT * FROM wp_term_taxonomy
    LEFT JOIN wp_terms ON (wp_term_taxonomy.term_id = wp_terms.term_id)
    WHERE (wp_terms.term_id IS NULL)

    DELETE wp_term_taxonomy FROM wp_term_taxonomy
    LEFT JOIN wp_terms ON (wp_term_taxonomy.term_id = wp_terms.term_id)
    WHERE (wp_terms.term_id IS NULL)
    ```

    ### wp_term_relationships -> wp_term_taxonomy

    ```sql
    SELECT * FROM wp_term_relationships
    LEFT JOIN wp_term_taxonomy ON (wp_term_relationships.term_taxonomy_id = wp_term_taxonomy.term_taxonomy_id)
    WHERE (wp_term_taxonomy.term_taxonomy_id IS NULL)

    DELETE wp_term_relationships FROM wp_term_relationships
    LEFT JOIN wp_term_taxonomy ON (wp_term_relationships.term_taxonomy_id = wp_term_taxonomy.term_taxonomy_id)
    WHERE (wp_term_taxonomy.term_taxonomy_id IS NULL)
    ```

    ### wp_usermeta -> wp_users

    ```sql
    SELECT * FROM wp_usermeta
    LEFT JOIN wp_users ON (wp_usermeta.user_id = wp_users.ID)
    WHERE (wp_users.ID IS NULL)

    DELETE wp_usermeta FROM wp_usermeta
    LEFT JOIN wp_users ON (wp_usermeta.user_id = wp_users.ID)
    WHERE (wp_users.ID IS NULL)
    ```

    ### wp_posts -> wp_users

    ```sql
    SELECT * FROM wp_posts
    LEFT JOIN wp_users ON (wp_posts.post_author = wp_users.ID)
    WHERE (wp_users.ID IS NULL)

    DELETE wp_posts FROM wp_posts
    LEFT JOIN wp_users ON (wp_posts.post_author = wp_users.ID)
    WHERE (wp_users.ID IS NULL)
    ```

    ## Other

    ### wp_postmeta dupes
    Checking for dupe `_wp_attached_file` / `_wp_attachment_metadata` keys (should only ever be one each per attachment post type).

    ```sql
    SELECT post_id,meta_key,meta_value
    FROM wp_postmeta
    WHERE (meta_key IN('_wp_attached_file','_wp_attachment_metadata'))
    GROUP BY post_id,meta_key
    HAVING (COUNT(post_id) > 1)
    ```

    ### wp_postmeta dupes #2
    Where an identical `meta_key` exists for the same post more than once.

    ```sql
    SELECT *,COUNT(*) AS keycount
    FROM wp_postmeta
    GROUP BY post_id,meta_key
    HAVING (COUNT(*) > 1)
    ```

    ### wp_postmeta missing
    Checking for missing `_wp_attached_file` / `_wp_attachment_metadata` keys on `wp_posts.post_type = 'Attachment'` rows.

    ```sql
    SELECT * FROM wp_posts
    LEFT JOIN wp_postmeta ON (
    (wp_posts.ID = wp_postmeta.post_id) AND
    (wp_postmeta.meta_key = '_wp_attached_file')
    )
    WHERE (wp_posts.post_type = 'Attachment') AND (wp_postmeta.meta_id IS NULL)

    SELECT * FROM wp_posts
    LEFT JOIN wp_postmeta ON (
    (wp_posts.ID = wp_postmeta.post_id) AND
    (wp_postmeta.meta_key = '_wp_attachment_metadata')
    )
    WHERE (wp_posts.post_type = 'Attachment') AND (wp_postmeta.meta_id IS NULL)
    ```

    ### wp_options '_transient_' rows
    A transient value is one stored by WordPress and/or a plugin generated from a complex query - basically a cache. More information on this can be found in this [answer on Stack Overflow](http://stackoverflow.com/a/11995022).

    ```sql
    DELETE FROM wp_options
    WHERE option_name LIKE '%\_transient\_%'
    ```