How do I convert the following SQL query to GORM?
SELECT * FROM files WHERE tsv ## plainto_tsquery('lexeme word');
Or equivalently:
SELECT * FROM files, plainto_tsquery('lexeme word') q WHERE tsv ## q;
I can use .Exec():
err := d.Connection.DB.Exec("SELECT * FROM scenes WHERE tsv ## plainto_tsquery(?);",text).Error
if err != nil {
return nil, err
}
This query doesn't allow me to get an array of data and work with it.
Unfortunately, I could not find a solution using the GORM documentation.
Use .Raw() for raw SQL query
db.Raw("SELECT id, name, age FROM users WHERE name = ?", 3).Scan(&result)
Official doc for about raw SQL query
Related
I am trying to use .UnionAll method in go-pg library for golang.
var model []Customer
q0 := db.Model(&model).Where("name = ?", name0).Limit(4)
q1 := db.Model(&model).Where("name = ?", name1).Limit(3)
var result []Customer
if err := q0.UnionAll(q1).Limit(1).Select(&result); !as.NoError(err) {
return
}
This code produces the query:
(SELECT "customer"."id", "customer"."name" FROM customers AS "customer" WHERE (name = 'customer 1deificatory zonoid reprepare alacrify serenissime')
LIMIT 1)
UNION ALL
(SELECT "customer"."id", "customer"."name" FROM customers AS "customer" WHERE (name = 'customer 2fordless ferroboron radiability dandizette smutch'
LIMIT 3)
)
But I expect it to be:
(SELECT "customer"."id", "customer"."name" FROM customers AS "customer" WHERE (name = 'customer 1deificatory zonoid reprepare alacrify serenissime')
LIMIT 4)
UNION ALL
(SELECT "customer"."id", "customer"."name" FROM customers AS "customer" WHERE (name = 'customer 2fordless ferroboron radiability dandizette smutch')
LIMIT 3)
LIMIT 1
So how to use go-pg to get raw SQL query which I expect?
The thing is I can't apply the Limit 1 expression to the whole query for some reason.
Also, my Limit 4 is not applied correctly to the first union all member.
My whole code is here.
I believe this query does the trick for you.
if err := db.Model().With("union_q", q0.UnionAll(q1)).Table("union_q").Limit(1).Select(&result); !as.NoError(err) {
return
}
The query isn't exactly what you wanted to be and as far as I know, the current version of go-pg can't generate that query. But this query does exactly what you wanted.
I have a simple select statement:
Select * FROM X where X.name in ("bob", "joe") and X.phone='123'
That works fine in postgres,
In my Go code I have the following code:
var phone string = "123"
var names []string = []string{"bob", "joe"}
sqlStatement := `Select * FROM X where X.name in ($1) and X.phone=$2`
rows, sqlerr := db.Query(sqlStatement, names, phone)
but for some reason I error out from that sql.
unsupported Scan, storing driver.Value type into type *string
how can i use my names array in side the sqlstatement?
note: if i do a fmt.printf and paste the sql statement into postgres, i do get data back + if i take out the $1, and manually input the strings
Copying and pasting fragments from some working Go PostgreSQL code:
import (
"database/sql"
"github.com/lib/pq"
)
query := `
. . .
WHERE code = ANY($1)
. . .
`
codes := []string{"JFK", "LGA", "EWR"}
rows, err := db.Query(query, pq.Array(codes))
I solved this using http://jmoiron.github.io/sqlx/#inQueries
var phone string = "123"
var names []string = []string{"bob", "joe"}
sqlStatement := `Select * FROM X where X.name in (?) and X.phone=?`
sqlStatement, args, err := sqlx.In(sqlStatement, names, phone)
sqlStatement = db.Rebind(sqlStatement)
rows, sqlerr := db.Queryx(sqlStatement, args...)
this now returns correctly.
another way to solve this was to use fmt.Sprintf() and converting the ? to %s
I am trying to execute the following query against the PostgreSQL database in Go using pq driver:
SELECT COUNT(id)
FROM tags
WHERE id IN (1, 2, 3)
where 1, 2, 3 is passed at a slice tags := []string{"1", "2", "3"}.
I have tried many different things like:
s := "(" + strings.Join(tags, ",") + ")"
if err := Db.QueryRow(`
SELECT COUNT(id)
FROM tags
WHERE id IN $1`, s,
).Scan(&num); err != nil {
log.Println(err)
}
which results in pq: syntax error at or near "$1". I also tried
if err := Db.QueryRow(`
SELECT COUNT(id)
FROM tags
WHERE id IN ($1)`, strings.Join(stringTagIds, ","),
).Scan(&num); err != nil {
log.Println(err)
}
which also fails with pq: invalid input syntax for integer: "1,2,3"
I also tried passing a slice of integers/strings directly and got sql: converting Exec argument #0's type: unsupported type []string, a slice.
So how can I execute this query in Go?
Pre-building the SQL query (preventing SQL injection)
If you're generating an SQL string with a param placeholder for each of the values, it's easier to just generate the final SQL right away.
Note that since values are strings, there's place for SQL injection attack, so we first test if all the string values are indeed numbers, and we only proceed if so:
tags := []string{"1", "2", "3"}
buf := bytes.NewBufferString("SELECT COUNT(id) FROM tags WHERE id IN(")
for i, v := range tags {
if i > 0 {
buf.WriteString(",")
}
if _, err := strconv.Atoi(v); err != nil {
panic("Not number!")
}
buf.WriteString(v)
}
buf.WriteString(")")
Executing it:
num := 0
if err := Db.QueryRow(buf.String()).Scan(&num); err != nil {
log.Println(err)
}
Using ANY
You can also use Postgresql's ANY, whose syntax is as follows:
expression operator ANY (array expression)
Using that, our query may look like this:
SELECT COUNT(id) FROM tags WHERE id = ANY('{1,2,3}'::int[])
In this case you can declare the text form of the array as a parameter:
SELECT COUNT(id) FROM tags WHERE id = ANY($1::int[])
Which can simply be built like this:
tags := []string{"1", "2", "3"}
param := "{" + strings.Join(tags, ",") + "}"
Note that no check is required in this case as the array expression will not allow SQL injection (but rather will result in a query execution error).
So the full code:
tags := []string{"1", "2", "3"}
q := "SELECT COUNT(id) FROM tags WHERE id = ANY($1::int[])"
param := "{" + strings.Join(tags, ",") + "}"
num := 0
if err := Db.QueryRow(q, param).Scan(&num); err != nil {
log.Println(err)
}
This is not really a Golang issue, you are using a string to compare to integer (id) in your SQL request. That means, SQL receive:
SELECT COUNT(id)
FROM tags
WHERE id IN ("1, 2, 3")
instead of what you want to give it. You just need to convert your tags into integer and passe it to the query.
EDIT:
Since you are trying to pass multiple value to the query, then you should tell it:
params := make([]string, 0, len(tags))
for i := range tags {
params = append(params, fmt.Sprintf("$%d", i+1))
}
query := fmt.Sprintf("SELECT COUNT(id) FROM tags WHERE id IN (%s)", strings.Join(params, ", "))
This will end the query with a "($1, $2, $3...", then convert your tags as int:
values := make([]int, 0, len(tags))
for _, s := range tags {
val, err := strconv.Atoi(s)
if err != nil {
// Do whatever is required with the error
fmt.Println("Err : ", err)
} else {
values = append(values, val)
}
}
And finally, you can use it in the query:
Db.QueryRow(query, values...)
This should do it.
Extending #icza solution, you can use pq.Array instead of building the params yourself.
So using his example, the code can look like this:
tags := []string{"1", "2", "3"}
q := "SELECT COUNT(id) FROM tags WHERE id = ANY($1::int[])"
num := 0
if err := Db.QueryRow(q, pq.Array(tags)).Scan(&num); err != nil {
log.Println(err)
}
I am trying to execute the following query against the PostgreSQL database in Go using pq driver:
SELECT COUNT(id)
FROM tags
WHERE id IN (1, 2, 3)
where 1, 2, 3 is passed at a slice tags := []string{"1", "2", "3"}.
I have tried many different things like:
s := "(" + strings.Join(tags, ",") + ")"
if err := Db.QueryRow(`
SELECT COUNT(id)
FROM tags
WHERE id IN $1`, s,
).Scan(&num); err != nil {
log.Println(err)
}
which results in pq: syntax error at or near "$1". I also tried
if err := Db.QueryRow(`
SELECT COUNT(id)
FROM tags
WHERE id IN ($1)`, strings.Join(stringTagIds, ","),
).Scan(&num); err != nil {
log.Println(err)
}
which also fails with pq: invalid input syntax for integer: "1,2,3"
I also tried passing a slice of integers/strings directly and got sql: converting Exec argument #0's type: unsupported type []string, a slice.
So how can I execute this query in Go?
Pre-building the SQL query (preventing SQL injection)
If you're generating an SQL string with a param placeholder for each of the values, it's easier to just generate the final SQL right away.
Note that since values are strings, there's place for SQL injection attack, so we first test if all the string values are indeed numbers, and we only proceed if so:
tags := []string{"1", "2", "3"}
buf := bytes.NewBufferString("SELECT COUNT(id) FROM tags WHERE id IN(")
for i, v := range tags {
if i > 0 {
buf.WriteString(",")
}
if _, err := strconv.Atoi(v); err != nil {
panic("Not number!")
}
buf.WriteString(v)
}
buf.WriteString(")")
Executing it:
num := 0
if err := Db.QueryRow(buf.String()).Scan(&num); err != nil {
log.Println(err)
}
Using ANY
You can also use Postgresql's ANY, whose syntax is as follows:
expression operator ANY (array expression)
Using that, our query may look like this:
SELECT COUNT(id) FROM tags WHERE id = ANY('{1,2,3}'::int[])
In this case you can declare the text form of the array as a parameter:
SELECT COUNT(id) FROM tags WHERE id = ANY($1::int[])
Which can simply be built like this:
tags := []string{"1", "2", "3"}
param := "{" + strings.Join(tags, ",") + "}"
Note that no check is required in this case as the array expression will not allow SQL injection (but rather will result in a query execution error).
So the full code:
tags := []string{"1", "2", "3"}
q := "SELECT COUNT(id) FROM tags WHERE id = ANY($1::int[])"
param := "{" + strings.Join(tags, ",") + "}"
num := 0
if err := Db.QueryRow(q, param).Scan(&num); err != nil {
log.Println(err)
}
This is not really a Golang issue, you are using a string to compare to integer (id) in your SQL request. That means, SQL receive:
SELECT COUNT(id)
FROM tags
WHERE id IN ("1, 2, 3")
instead of what you want to give it. You just need to convert your tags into integer and passe it to the query.
EDIT:
Since you are trying to pass multiple value to the query, then you should tell it:
params := make([]string, 0, len(tags))
for i := range tags {
params = append(params, fmt.Sprintf("$%d", i+1))
}
query := fmt.Sprintf("SELECT COUNT(id) FROM tags WHERE id IN (%s)", strings.Join(params, ", "))
This will end the query with a "($1, $2, $3...", then convert your tags as int:
values := make([]int, 0, len(tags))
for _, s := range tags {
val, err := strconv.Atoi(s)
if err != nil {
// Do whatever is required with the error
fmt.Println("Err : ", err)
} else {
values = append(values, val)
}
}
And finally, you can use it in the query:
Db.QueryRow(query, values...)
This should do it.
Extending #icza solution, you can use pq.Array instead of building the params yourself.
So using his example, the code can look like this:
tags := []string{"1", "2", "3"}
q := "SELECT COUNT(id) FROM tags WHERE id = ANY($1::int[])"
num := 0
if err := Db.QueryRow(q, pq.Array(tags)).Scan(&num); err != nil {
log.Println(err)
}
As PostgreSQL connector I import following package:
_ "github.com/lib/pq"
The query I run is:
res, err := db.Query("SELECT id FROM applications WHERE email='" + email + "'")
where email is naturally a string. One way to count the number of rows in res is by following snippet
count:=0
for res.Next() {
count++
//some other code
}
but there should be some simpler (and quicker) way. It seems RowsAffected() is not the way to go. So, what is your suggestion?
Use the COUNT function:
"SELECT count(*) FROM applications WHERE email='" + email + "'"