database/sql: Creating a []map[string]interface{} from sql.Rows?

Craig Weber

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Nov 30, 2015, 10:10:06 AM11/30/15

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Hello,

I need to build a []map[string]interface{} from sql.Rows, but I can't figure out how to do it. I came across this question on StackOverflow (http://stackoverflow.com/questions/17840963/create-a-map-in-golang-from-database-rows), but none of the answers are satisfactory (it's also a dated question). I wanted to check to see if anyone on this list had any better solutions, preferably using the standard library if it's not overly complex.

Thanks,
Craig

Kyle Wolfe

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Nov 30, 2015, 10:37:51 AM11/30/15

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Craig,

If you know what the table structure is ahead, it's trivial to do a normal scan and then return a map[string]interface{} form your scan. Beccause of this, I'm assuming that you have a situation where you're unaware of the table structure at runtime and your doing a "select *" all the time? If this is the case, databse/sql is not set up for this use case from what I see in the do, as driver.Value is not exported (https://golang.org/src/database/sql/sql.go#L1615). With that said, I agree with the first response in that SO. Use sqlx (https://godoc.org/github.com/jmoiron/sqlx#Row.MapScan)

C Banning

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Nov 30, 2015, 12:33:12 PM11/30/15

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Get a Rows value, 'r', with the db.Query(). r.Columns has the map keys in sequence - 'cols'; r.Next() will get you a row; and r.Scan() will walk through the values for the map keys in sequence of cols[i].