Add Create hstore From Two Arrays as a postgres til.

README.md

@@ -121,6 +121,7 @@ smart people at [Hashrocket](http://hashrocket.com/).
 - [Configure The Timezone](postgres/configure-the-timezone.md)
 - [Count Records By Type](postgres/count-records-by-type.md)
 - [Create A Composite Primary Key](postgres/create-a-composite-primary-key.md)
+- [Create hstore From Two Arrays](postgres/create-hstore-from-two-arrays.md)
 - [Default Schema](postgres/default-schema.md)
 - [Defining Arrays](postgres/defining-arrays.md)
 - [Edit Existing Functions](postgres/edit-existing-functions.md)

postgres/create-hstore-from-two-arrays.md

@@ -0,0 +1,20 @@
+# Create hstore From Two Arrays
+
+PostgreSQL allows the use of the `hstore` type by enabling the `hstore`
+extension. One way to create an instance of `hstore` data is by passing two
+arrays to the `hstore()` function. The first array is a set of keys and the
+second array is the set of values.
+
+```sql
+> select hstore(array['one','two','three'], array['1','2','3']);
+                hstore
+--------------------------------------
+ "one"=>"1", "two"=>"2", "three"=>"3"
+```
+
+The two arrays must be the same length or an error will occur.
+
+```sql
+> select hstore(array['one','two','three'], array['1','2']);
+ERROR:  arrays must have same bounds
+```