Re-add old blog posts from Astro

source/_posts/add-taxonomy-term-multiple-nodes-using-sql.md

@@ -0,0 +1,79 @@
+---
+title: Add a Taxonomy Term to Multiple Nodes Using SQL
+date: 2010-07-07
+excerpt: How to add a new taxonomy term to multiple nodes in Drupal using SQL.
+tags:
+    - database
+    - drupal-6
+    - drupal-planet
+    - sequal-pro
+    - sql
+    - taxonomy
+---
+
+In preparation for my Blog posts being added to
+[Drupal Planet](http://drupal.org/planet), I needed to create a new Taxonomy
+term (or, in this case, tag) called 'Drupal Planet', and assign it to new
+content to imported into their aggregator. After taking a quick look though my
+previous posts, I decided that 14 of my previous posts were relevant, and
+thought that it would be useful to also assign these the 'Drupal Planet' tag.
+
+I didn't want to manually open each post and add the new tag, so I decided to
+make the changes myself directly into the database using SQL, and as a follow-up
+to a previous post -
+[Quickly Change the Content Type of Multiple Nodes using SQL](/blog/change-content-type-multiple-nodes-using-sql/).
+
+**Again, before changing any values within the database, ensure that you have an
+up-to-date backup which you can restore if you encounter a problem!**
+
+The first thing I did was create the 'Drupal Planet' term in my Tags vocabulary.
+I decided to do this via the administration area of my site, and not via the
+database. Then, using [Sequel Pro](http://www.sequelpro.com), I ran the
+following SQL query to give me a list of Blog posts on my site - showing just
+their titles and nid values.
+
+```sql
+SELECT title, nid FROM node WHERE TYPE = 'blog' ORDER BY title ASC;
+```
+
+I made a note of the nid's of the returned nodes, and kept them for later. I
+then ran a similar query against the term_data table. This returned a list of
+Taxonomy terms - showing the term's name, and it's unique tid value.
+
+```sql
+SELECT NAME, tid FROM term_data ORDER BY NAME ASC;
+```
+
+The term that I was interested in, Drupal Planet, had the tid of 84. To confirm
+that no nodes were already assigned a taxonomy term with this tid, I ran another
+query against the database. I'm using aliases within this query to link the
+node, term_node and term_data tables. For more information on SQL aliases, take
+a look at <http://w3schools.com/sql/sql_alias.asp>.
+
+```sql
+SELECT * FROM node n, term_data td, term_node tn WHERE td.tid = 84 AND n.nid = tn.nid AND tn.tid = td.tid;
+```
+
+As expected, it returned no rows.
+
+The table that links node and term_data is called term_node, and is made up of
+the nid and vid columns from the node table, as well as the tid column from the
+term_data table. Is it is here that the additional rows would need to be
+entered.
+
+To confirm everything, I ran a simple query against an old post. I know that the
+only taxonomy term associated with this post is 'Personal', which has a tid
+value of 44.
+
+```sql
+SELECT nid, tid FROM term_node WHERE nid = 216;
+```
+
+Once the query had confirmed the correct tid value, I began to write the SQL
+Insert statement that would be needed to add the new term to the required nodes.
+The nid and vid values were the same on each node, and the value of my taxonomy
+term would need to be 84.
+
+Once this had completed with no errors, I returned to the administration area of
+my Drupal site to confirm whether or not the nodes had been assigned the new
+term.