How can I do conditional actions in SQLX - go

Question

I have database store function:
func (p *ProductsRep) FindAll(PageNumber int, PaginationSize int, Query string) []*postgresmodels.Product {
Also I have SQL query look like this:
SELECT * FROM table_name.
Then I want to concat conditional action like WHERE some_value=3 if some value (in this case Query) exists then I want to get SELECT * FROM table_name WHERE some_value=3.
I tried to use fmt.Sprintf to concat, or strings.Join, or bytes.Buffer.WriteString. But everytime I getting this error:
I replace real value for understanding:
pq: column "Some value" does not exist.
How can I do "adaptive" queries, which depends on inputed function values.

Answer 1

I believe you are trying to query rows in the database by using parameters.
You need to make sure you don't pass this data in as RAW values, due to the potential risk of SQL injection. You can make queries by using store procedures
You can use the function Query to pass in your query with your parameters. In the example case this is $1. If you wanted to you could add $2, $3... etc depending on how many parameters you wanted to query
Here is two examples
Postgres
using "github.com/jackc/pgx/v4" driver
ctx := context.Background()
type Bar struct {
ID int64
SomeValue string
}
rows, err := conn.Query(ctx, `SELECT * FROM main WHERE some_value=$1`, "foo")
if err != nil {
fmt.Println("ERRO")
panic(err) // handle error
}
defer rows.Close()
var items []Bar
for rows.Next() {
var someValue string
var id int64
if err := rows.Scan(&id, &someValue); err != nil {
log.Fatal(err) // handle error
}
item := Bar{
ID: id,
SomeValue: someValue,
}
items = append(items, item)
}
fmt.Println(items)
MySQL Driver
https://golang.org/pkg/database/sql/#DB.QueryRow
type Bar struct {
ID int64
SomeValue string
}
rows, err := conn.Query(`SELECT * FROM main WHERE some_value=$1`, "foo")
if err != nil {
fmt.Println("ERRO")
panic(err) // handle error
}
defer rows.Close()
var items []Bar
for rows.Next() {
var someValue string
var id int64
if err := rows.Scan(&id, &someValue); err != nil {
log.Fatal(err) // handle error
}
item := Bar{
ID: id,
SomeValue: someValue,
}
items = append(items, item)
}
fmt.Println(items)