Go PostgreSQL: How to obtain number of rows from a db.Query?

Question

As PostgreSQL connector I import following package:

_ "github.com/lib/pq"

The query I run is:

res, err := db.Query("SELECT id FROM applications WHERE email='" + email + "'")

where email is naturally a string. One way to count the number of rows in res is by following snippet

count:=0
for res.Next() {
  count++
  //some other code
}

but there should be some simpler (and quicker) way. It seems RowsAffected() is not the way to go. So, what is your suggestion?

Possible duplicate of How to find the rows count returned from db.Query postgres — damoiser
– damoiser, Commented Oct 7, 2016 at 6:58

dsh · Accepted Answer · 2015-10-08 14:52:25Z

0

Use the COUNT function:

"SELECT count(*) FROM applications WHERE email='" + email + "'"

edited Oct 8, 2015 at 14:52

dsh

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answered Oct 7, 2015 at 13:07

Luis Carlos

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4 Comments

Sami Kuhmonen Over a year ago

Please only post answers in English

Kulix Over a year ago

You should NOT be constructing SQL queries like this. This is prone to SQL injection, you should use prepared statements.

Luis Carlos Over a year ago

Kulix, I'm not totally agree with you in this case. Certainly this type of query is prone to SQL injection, but if you validate that the email var is a valid email you avoid that problem. There's different ways to solve problems, as a commentary is good your point but I don't think this is a wrong answer at all.

Kulix Over a year ago

What happens when your validation is bugged? SQL injection. This is absolutely the wrong way to construct a SQL query in all cases.

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