如何使用golang sql在postgres中选择整个表格？

Question

I'm fairly new to posgres and Go, but have been struggling for a while on this. I'm currently trying to send a query to retrieve everything from a table. When I try to use

SELECT * FROM land_registry_price_paid_uk

within postgres, it shows everything, but when I do the same using Query, I get.

sql: expected 16  destination arguments in Scan, not 1

This is the current code that I have.

fmt.Printf("user: %s, password: %s, dbName: %s", user, password, dbName)
connectionString := fmt.Sprintf("user=%s password=%s dbname=%s sslmode=%s", user, password, dbName, "disable")
var err error
a.DB, err = sql.Open("postgres", connectionString)
if err != nil {
    log.Fatal(err)
}
rows, err := a.DB.Query("SELECT ( * ) FROM land_registry_price_paid_uk")
if err != nil {
    log.Fatal(err)
}
defer rows.Close()
println(rows)
for rows.Next() {
    var name string
    if err := rows.Scan(&name); err != nil {
        log.Fatal(err)
    }
    fmt.Printf("this is something: %s
", name)

Any help is appreciated.

Answer 1

Looks like your query is working just fine, you are returning 16 columns of data and trying to scan them all into a single string variable, you will need to provide a holder variable for each column:

var name string
// vars to hold other column values go here

// then reference vars in table order as args to row.Scan below
if err := rows.Scan(&name); err != nil {
    log.Fatal(err)
}

if you have not used sql/go before you may also want to look into the special types provided for coping with nullable values as you will likely need these as well:

NullString example

Update:

To further illustrate, say you had a three column table which consisted of the following fields:

• id (int)
• name (string)
• optional_data (string, nullable)

You might read the row as follows (not tested):

var (
    id int 
    name string
    optionalData sql.NullString
)

if err := rows.Scan(&id, &name, &optionalData); err != nil {
    log.Fatal(err)
}