I want to delete all database entries in my Postgres database that are older than X minutes. My prepared statement in go looks like this:
delete
from my_table
where expires < (to_timestamp($1) - '$2 minutes'::interval);
How can I correctly pass the second parameter $2
?
PS: I know there's different statements to solve the problem, but I am explicitly interested in how to pass parameters that are quoted.
You can cast the parameter to text
and then concatenate it with the string ' minutes'
.
delete from my_table
where expires < (to_timestamp($1) - ($2::text || ' minutes')::interval
UPDATE: actually, since postgres does have a any || text
any || text
operator, the result of which is text
, you shouldn't need to type cast the parameter.
There is no way to interpolate a parameter into a string literal.
A possible solution for your case would be to multiply a number with an interval:
where expires < (to_timestamp($1) - $2 * '1 minute'::interval)
You can use make_interval
delete from my_table
where expires < (to_timestamp($1) - make_interval(mins => $2));
You can also parametrize the entire interval string instead. This removes the need for an intermediate cast to text
and concat.
query := `
delete from my_table
where expires < (to_timestamp($1) - $2::interval);
`
interval := fmt.Sprintf("%d minutes", mins)
db.Exec(query, timestamp, interval)
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