how do I query a sqlite db in go? [closed] - sqlite

Question

Closed. This question needs details or clarity. It is not currently accepting answers.
Want to improve this question? Add details and clarify the problem by editing this post.
Closed 1 year ago.
Improve this question
I'm trying to get an array of "Search" structs.
type Searches struct {
id int
count int
search string
}
func get_recent_searches(db *sql.DB, limit int) []Searches {
var searches []Searches
var query = "select from searches brder by count desc limit ?"
st, err := db.Prepare(query)
result, err := st.Exec(limit)
if err != nil { panic(err) }
/*
for rows.Next() {
item := Searches{}
err2 := rows.Scan(&item.id, &item.count, &item.search)
if err2 != nil { panic(err2) }
searches = append(searches, item)
}
*/
return result
}
Here is the error:
src/main.go:72:2: cannot use result (type sql.Result) as type []Searches in return argument

Answer 1

package main
import (
"fmt"
"log"
"database/sql"
_ "github.com/mattn/go-sqlite3" // Import go-sqlite3 library
)
// Searches ...
type Searches struct {
id int
count int
search string
}
func getRecentSearches(db *sql.DB, limit int) []Searches {
var searches []Searches
row, err := db.Query("SELECT * FROM search ORDER BY count LIMIT ?", limit)
if err != nil {
log.Fatal(err)
}
defer row.Close()
for row.Next() { // Iterate and fetch the records from result cursor
item := Searches{}
err := row.Scan(&item.id, &item.count, &item.search)
if err != nil {
log.Fatal(err)
}
searches = append(searches, item)
}
return searches
}
func main() {
searchDB, _ := sql.Open("sqlite3", "./search.db") // Open the created SQLite File
defer searchDB.Close() // Defer Closing the database
// Get and print the first 5 records to the console
searches := getRecentSearches(searchDB, 4)
fmt.Printf("ID\tCount\tSearch\n")
for _, item := range searches {
fmt.Printf("%d\t%d\t%s\n", item.id, item.count, item.search)
}
}

Answer 2

This link explains how to use SQLite with go: https://astaxie.gitbooks.io/build-web-application-with-golang/content/en/05.3.html
But the error you are seeing is because your function is defined as
func get_recent_searches(db *sql.DB, limit int) []Searches {}
It must return []Searches (a slice of Searches structs). (NB I would probably name a single search result as Search).
Adding the fixes suggested by #Peter Gloor (Query to return rows, rather than an Exec to change data) and removing the limit placeholder, your code could be
func get_recent_searches(db *sql.DB, limit int) []Searches {
searches := make([]Searches,0)
query := "select * from searches order by count desc"
st, err := db.Prepare(query)
if err != nil { panic(err) }
rows, err := st.Query(limit)
if err != nil { panic(err) }
for rows.Next() {
item := Searches{}
err2 := rows.Scan(&item.id, &item.count, &item.search)
if err2 != nil { panic(err2) }
searches = append(searches, item)
}
return searches
}