Use the HSTORE column type. HSTORE stores key/value pairs. You can use null values if you only care about checking if a key exists. See https://www.postgresql.org/docs/current/static/hstore.html. For example, to ask Is ‘x’ in my hstore?, do CREATE EXTENSION HSTORE; –create extension only has to be done once SELECT * FROM ‘x=>null,y=>null,z=>null’::HSTORE ? ‘x’; I believe … Read more
It’s exactly the same thing. No need to pick one instead of the other. Usually default keyword is handy when you have computer-generated code. It makes life easier to just use every single column in the insert clause and just use default when you don’t have a specific value for certain column. Other than that, … Read more
I don’t think that default Rails validators will do the trick here, you can do this though: validate :validate_wdays def validate_wdays if !wdays.is_a?(Array) || wdays.any?{|d| !(0..6).include?(d)} errors.add(:wdays, :invalid) end end
About the permissions: Don’t forget that to access a file you need permissions on all directories in the path. So if, for example, the OS user postgres does not have permissions on the /home/MyUser directory, you get the observed error message. About \copy: You have to use the -c option to supply a command to … Read more
A year is an integer and even supports integer arithmetic in a meaningful way so text makes no sense. You don’t have a month or day so date is right out the window. The fine manual has this to say about smallint: The smallint type is generally only used if disk space is at a … Read more
If you want to use a local password less connection then you need to remove the values “HOST”, “PORT” and “PASSWORD”. With this configuration your connector will try to connect using a unix domain socket which is the only allowed password less connection allowed by default in Postgres
uuid is a specific datatype. To you it looks like text, but it’s not. You cannot compare uuid using string functions (uuid like “abc%”), or compare it with text. As Tamer suggests, you can cast it first, if you need to compare. SELECT * FROM (SELECT ‘A0EEBC99-9C0B-4EF8-BB6D-6BB9BD380A11’::uuid as my_uuid) foo WHERE my_uuid::text like ‘a%’ For … Read more
I don’t know if this qualifies as “more elegant” but it is written in a different manner than Cybernate’s solution (although it is essentially the same) WITH window_table AS ( SELECT s.*, sum(volume) OVER previous_rows as total FROM stuff s WINDOW previous_rows as (ORDER BY priority desc ROWS between UNBOUNDED PRECEDING and CURRENT ROW) ) … Read more
Locks are taken during (usually at or near the beginning of) a command’s execution. Locks (except advisory locks) are released only when a transaction commits or rolls back. There is no FOR UNLOCK, nor is there an UNLOCK command to reverse the effects of the table-level LOCK command. This is all explained in the concurrency … Read more
This sequelize github issue looks totally like your case: User.findAll({ attributes: [‘User.*’, ‘Post.*’, [sequelize.fn(‘COUNT’, ‘Post.id’), ‘PostCount’]], include: [Post] });