The range type would allow best performance and simple queries.
If you have some string values like k and Pre-K mixed with numeric values, just create a grade table with a rank value (an integer value representing actual sort order):
CREATE TABLE grade(
grade text PRIMARY KEY
,grade_int UNIQUE int NOT NULL
);
Your numeric grades can conveniently be assigned the same grade_value, other grades get integer values according to their rank.
You might write a simple function to convert ranges with your original string values to their integer representations on the fly ...
And vice-versa to display your grades_served column where needed.
Convert grades_served to an int4range type.
Using the overlap operator &&, your query for a range of grades can then simply be:
SELECT * FROM tbl WHERE grades_served && '[1,4]'::int4range;
Or, for a single grade, the "contains element" operator @>
SELECT * FROM tbl WHERE grades_served @> -1;
Index
If your table is not very small I suggest you create a GiST index to support that (and so does the manual).
CREATE INDEX tbl_grades_served_idx ON tbl USING gist (grades_served);
So I received help on this issue from a colleague who is an experienced programmer.
In order to add a password to the page:
sudo nano /etc/apache2/conf-enabled/phppgadmin.conf
Then, modify the .conf file to include the following text within the block (I placed it underneath the 'allow from all' line that I uncommented previously):
AuthUserFile /usr/share/phppgadmin/.htpasswd
AuthName "Restricted Area"
AuthType Basic
require valid-user
Save this file and exit.
Change directory to phppgadmin:
cd /usr/share/phppgadmin
Create password file (change 'your username' and get rid of triangle brackets):
sudo htpasswd -c .htpasswd <your username>
Enter password twice when prompted.
Restart the apache service and the page will now be password protected.
In order to add a superuser to access phppgadmin(again, (change 'your username' and get rid of triangle brackets):
sudo su - postgres
createuser -P -s <your username>
Again, enter password twice when prompted. This will now allow you to login to to phppgadmin.
Erwin's answer is also helpful too, it just seems as if he takes a different approach to solving the issue. Although I did not use Erwin's method, it should accomplish the same thing. However, I did not need to adjust listen_address in postgresql.conf in order to make it work.
Best Answer
I don't use phpPgAmin.
To change an existing column definition to use the
CYCLEattribute you need to understand that this is an attribute of the sequence not the "column".A
serialorbigserialis only a shorthand notation to assign a default value to a column which is take from a sequence.When you define a column as
serialPostgres automatically creates a sequences and applies the necessary default expression.The sequence is usually called
<table_name>_<column_name>_seq. But you can run a query to get the name of the generated sequence:Once you know the name of the sequence, you can do the following:
(Note that you need to
committhat if you are not using auto-commit mode).Here are some relevant links to the manual:
ALTER SEQUENCE: http://www.postgresql.org/docs/current/static/sql-altersequence.html