How to use sqlx to query mysql IN a slice?

问题

I want to query a table in mysql database for values IN a slice:

var qids []int
//fill qids dynamically
err = database.SQL.Select(&quotes,
    "SELECT * FROM quote WHERE qid IN $1", qids)
if err != nil {
    log.Println(err)
}

But I get this error:

sql: converting Exec argument #0's type: unsupported type []int, a slice
quotes []

How can I fix this?

回答1:

sqlx has a great helper for that: In() we just have to prepare the query taking the args and Rebind, like this:

var qids []int

// fills qids on query dynamically
query, args, err := sqlx.In("SELECT * FROM quote WHERE qid IN (?)", qids)
if err != nil {
    log.Fatal(err)
}

// sqlx.In returns queries with the `?` bindvar, we can rebind it for our backend
//
query = database.SQL.Rebind(query)  // database.SQL should be a *sqlx.DB

err = database.SQL.Select(&quotes, query, args...)
if err != nil {
    log.Fatal(err)
}

// or just in one line:

err = database.SQL.Select(&quotes, database.SQL.Rebind(query), args...)

Also I recommend you take a look here: http://jmoiron.github.io/sqlx/ there're a lot of examples including IN

回答2:

Hey its because of []int
try this

type Int64Array []int64

// Value returns the driver compatible value
func (a Int64Array) Value() (driver.Value, error) {
var strs []string
for _, i := range a {
    strs = append(strs, strconv.FormatInt(i, 10))
}
return "{" + strings.Join(strs, ",") + "}", nil
}

and then pass int64 to query

db.Queryx("SELECT * FROM quote WHERE qid IN $1", int64IDs)

for more detail check here

回答3:

The tags suggest that you are using sqlx. It has support for IN in queries.

So you can do

var qids []int
//fill qids dynamically
rows, err = db.Query(&quotes, "SELECT * FROM quote WHERE qid IN ($1)", qids)
if err != nil {
    log.Println(err)
}
// scan the rows

来源：https://stackoverflow.com/questions/40565805/how-to-use-sqlx-to-query-mysql-in-a-slice

标签

mysql

sqlx