Squirrel Xtended (sqx
) is a convenient library for db interactions in go. It provides nice bindings around:
- Masterminds/squirrel - for fluent SQL generation
- blockloop/scan - for data marshalling
- Go 1.18 Generics
sqx
is not an ORM or a migration tool. sqx
just wants to run some SQL!
Links
Teach sqx
where your DB handle and logger are. sqx
can then be used to create, update, and delete data.
See Widget Test for an example of a complete data layer built with sqx
.
package main
import (
"context"
"github.com/stytchauth/sqx"
)
func init() {
db := getDatabase()
log := getLogger()
sqx.SetDefaultQueryable(db)
sqx.SetDefaultLogger(log)
}
type User struct {
ID string `db:"id"`
Email string `db:"email"`
PhoneNumber string `db:"phone_number"`
Status string `db:"status"`
}
func InsertUser(ctx context.Context, user *User) error {
return sqx.Write(ctx).
Insert("users").
SetMap(sqx.ToSetMap(user)).
Do()
}
type GetUserFilter struct {
ID *string `db:"id"`
Email *string `db:"email"`
PhoneNumber *string `db:"phone_number"`
Status *string `db:"status"`
}
func GetUsers(ctx context.Context, filter GetUserFilter) ([]User, error) {
return sqx.Read[User](ctx).
Select("*").
From("users").
Where(sqx.ToClause(filter)).
All()
}
func DeleteUser(ctx context.Context, userID string) error {
return sqx.Write(ctx).
Delete("users").
Where(sqx.Eq{"ID": userID}).
Do()
}
sqx
is a superset of Masterminds/squirrel - refer to their docs for information on what query methods are available.
We will try to add more examples over time - if there is an example you'd love to see, feel free to open an issue or a PR!
Call sqx.Read[T](ctx).Select(columNames...)
to start building a read transaction. When the read transaction is ran,
sqx
will provision an object of type T
and scan the results into the object. Scanning is accomplished using db
tags defined on T
.
All scanning is handled by blockloop/scan's RowsStrict
method.
Read transactions can be ran in several ways:
func (b SelectBuilder[T]) One() (*T, error)
- reads a single struct of typeT
. If no response is found, returns asql.ErrNoRows
. If more than one row is returned from the underlying query, an error will be logged to the provided logger.func (b SelectBuilder[T]) OneStrict() (*T, error)
- likeOne()
but returns an error if more than one row is returnedfunc (b SelectBuilder[T]) OneScalar() (T, error)
- likeOne()
but can be used to read simple values likeint32
orstring
func (b SelectBuilder[T]) First() (*T, error)
- lineOne()
but does not care if the underlying query has more than one result and will just take the first row. NOTE: if you don't supply an OrderBy clause, the first result is not guaranteed to be the same each time you run the query.func (b SelectBuilder[T]) FirstScalar() (T, error)
- lineFirst()
but can be used to read simple values likeint32
orstring
func (b SelectBuilder[T]) All() ([]T, error)
- returns a slice of structs of typeT
You'll often want to filter the data that you read - for example, finding all Users
with a certain status, or finding a User
with a specific ID.
sqx.ToClause
is helpful for converting flexible structs into Where
-compatible filters. nil
-valued fields are ignored,
and only present fields are preserved.
For example, the following struct definition can be used to find users with a specific ID, a specific Email, a specific PhoneNumber, or any combination thereof.
type GetUserFilter struct {
ID *string `db:"id"`
Email *string `db:"email"`
PhoneNumber *string `db:"phone_number"`
}
Clause | Output |
---|---|
sqx.ToClause(GetUserFilter{ID: sqx.Ptr("123")}) |
sqx.Eq{"id": "123"} |
sqx.ToClause(GetUserFilter{Email: sqx.Ptr("[email protected]")}) |
sqx.Eq{"email": "[email protected]"} |
sqx.ToClause(GetUserFilter{ID: sqx.Ptr("123"), Email: sqx.Ptr("[email protected]")}) |
sqx.Eq{"id": "123", "email": "[email protected]"} |
func GetUsers(ctx context.Context, filter GetUserFilter) ([]User, error) {
return sqx.Read[User](ctx).
Select("*").
From("users").
Where(sqx.ToClause(filter)).
All()
}
If you are joining tables together and aliasing them along the way, sqx.ToClauseAlias
can help with that.
func GetUsersAndProfileData(ctx context.Context, filter GetUserFilter) ([]User, error) {
return sqx.Read[UserWithPets](ctx).
Select("*").
From("users u").
Join("pets p ON users.id = pets.user_id")
Where(sqx.ToClauseAlias("u", filter)).
All()
}
You can also define the alias directly in the struct tag
type GetUserWithPetFilter struct {
UserID *string `db:"u.id"`
PetID *string `db:"p.id"`
}
Call sqx.Write(ctx)
to start building a write transaction. Write transactions can be used for Create
, Update
, or Delete
operations.
All write transactions are ran by calling .Do()
after being built.
Create and Update transactions require fields to be set. Fields may be set one at a time via calls to .Set(fieldName string, fieldValue any)
but the preferred way
is via .SetMap(map[string]any)
. The method sqx.ToSetMap
is useful for converting flexible structs into maps.
As with ToClause
, nil
-valued fields are ignored, and only present fields are passed through.
For example, the following structs define a user that can be created once, then updated any number of times.
The UserUpdate
struct can be used to update a user's email, phone number, status, or multiple at once.
type User struct {
ID string `db:"id"`
Email string `db:"email"`
PhoneNumber string `db:"phone_number"`
Status string `db:"status"`
}
type UserUpdate struct {
Email *string `db:"email"`
PhoneNumber *string `db:"phone_number"`
Status *string `db:"status"`
}
Input | Output |
---|---|
sqx.ToSetMap(User{ID:"123", Email:"[email protected]"}) |
map[string]any{"id":"123", "email":"[email protected]", "phone_number": "", "status":""} |
sqx.ToSetMap(UserUpdate{ID:sqx.Ptr("123"), Email:sqx.Email("[email protected]")}) |
map[string]any{"id":"123", "email":"[email protected]"} |
func InsertUser(ctx context.Context, user *User) error {
return sqx.Write(ctx).
Insert("users").
SetMap(sqx.ToSetMap(user)).
Do()
}
func UpdateUser(ctx context.Context, userID string, update *UserUpdate) error {
return sqx.Write(ctx).
Update("users").
Where(sqx.Eq{"id": userID}).
SetMap(sqx.ToSetMap(update)).
Do()
}
--
sqx
is actively tested against mysql
.
Since sqx
is built on top of squirrel
, it should support all SQL dialects squirrel
supports.
squirrel
is tested against mysql
, postgres
, and sqlite
.
func GetUser(ctx context.Context, userID string) (*User, error) {
return sqx.Read[User](ctx).
Select("*").
From("users").
Where(sqx.Eq{"ID": userID}).
One()
}
func CountUsers(ctx context.Context, userID string) (int32, error) {
return sqx.Read[int32](ctx).
Select("COUNT(*)").
From("users").
OneScalar()
}
func GetAllUsers(ctx context.Context) ([]User, error) {
return sqx.Read[User](ctx).
Select("*").
From("users").
All()
}
Call .Debug()
at any time to print out the internal state of the query builder
sqx.Read[UserWithPets](ctx).
Select("*").
From("users u").
Debug().
Join("pets p ON users.id = pets.user_id").
Where(sqx.ToClauseAlias("u", filter)).
Debug().
All()
// outputs
// map[args:[] error:<nil> sql:SELECT * FROM users u]
// map[args:[poodle] error:<nil> sql:SELECT * FROM users u JOIN pets p ON users.id = pets.user_id WHERE u.breed = ?]
Use the sqx.Nullable[T]
type and its helper methods - sqx.NewNullable
and sqx.NewNull
.
Given the update request:
type PetUpdate {
UserID sqx.Nullable[string] `db:"user_id"`
}
func UpdatePets(ctx context.Context, petID string, petUpdate *PetUpdate) error {
return sqx.Write(ctx).
Update("pets").
Where(sqx.Eq{"id": petID}).
SetMap(sqx.ToClause(petUpdate)).
Do()
}
This update will set the user_id
field to the provided value
UpdatePets(ctx, &PetUpdate{
UserID: sqx.NewNullable("some-user-id")
})
and this update will set the user_id
field to NULL
/nil
UpdatePets(ctx, &PetUpdate{
UserID: sqx.NewNull[string]()
})
InsertBuilder.SetMap()
can take in an optional error. If an error occurs, the insert operation will short-circuit.
type Pet struct {
Name string `db:"name"`
}
func (p *Pet) ToSetMap() (map[string]any, error) {
if p.name == "" {
return nil, fmt.Errorf("pet was missing name")
}
return sqx.ToSetMap(p), nil
}
func CreatePet(ctx context.Context, pet *Pet) error {
return sqx.Write(ctx).
Insert("pets").
SetMap(pet.ToSetMap()).
Do()
}
sqx
does not manage transactions itself. Create transactions within your application when needed, and then pass to
WithQueryable
to let the request builder know to use that transaction object. Both sql.DB
and sql.Tx
satisfy the sqx.Queryable
interface.
func MyOperationThatNeedsATransaction(ctx context.Context) error {
// Get a Tx for making transaction requests.
tx, err := db.BeginTx(ctx, nil)
if err != nil {
return err
}
// Defer a rollback in case anything fails.
defer tx.Rollback()
err = OperationThatNeedsAQueryable(ctx, tx)
if err != nil {
return err
}
err = OperationThatNeedsAQueryable(ctx, tx)
if err != nil {
return err
}
return tx.Commit()
}
func OperationThatNeedsAQueryable(ctx context.Context, tx sqx.Queryable) error {
return sqx.Write(ctx).
WithQueryable(tx).
Update("table").
Set("key", "value").
Do()
}
Have multiple database handles or a per-request logger? You can override them using WithQueryable
or WithLogger
.
func GetUsersFromReadReplica(ctx context.Context, filter GetUserFilter) ([]User, error) {
return sqx.Read[User](ctx).
WithQueryable(replicaDB).
WithLogger(logging.FromCtx(ctx))
Select("*").
From("users").
Where(sqx.ToClause(filter)).
All()
}
If you always want to pass in a custom handle or logger, consider aliasing the Read
and Write
entrypoints within your project.
func Read[T any](ctx context.Context, db sqx.Queryable) interface {
Select(columns ...string) sqx.SelectBuilder[T]
} {
return sqx.Read[T](ctx).WithQueryable(db).WithLogger(logging.FromContext(ctx))
}
func Write(ctx context.Context, db sqx.Queryable) interface {
Insert(tblName string) sqx.InsertBuilder
Update(tblName string) sqx.UpdateBuilder
Delete(tblName string) sqx.DeleteBuilder
} {
return sqx.Write(ctx).WithQueryable(db).WithLogger(logging.FromContext(ctx))
}
sqx
is made to operate in a sweet spot just slightly past "query builder", but well before "ORM".
The closest analog for sqx
is knex.js
- a Node query builder with wonderful DX.
sqx
wants to eliminate boilerplate commonly found in DB IO operations based on Rob Pike's Errors are values essay.
Returning to our quick-start example, we see that sqx
lets us create reusable DB query patterns with
a minimal amount of boilerplate, while also not obscuring the SQL query that is generated. The following snippet shows
a single function that can be ran in several different ways - to list all users in the table, to filter users by ID,
or to filter by a number of other fields.
func GetUsers(ctx context.Context, filter GetUserFilter) ([]User, error) {
return sqx.Read[User](ctx).
Select("*").
From("users").
Where(sqx.ToClause(filter)).
All()
}
Here's some sample code showing how someone might write the GetUsers
function defined above using the stdlib.
We want to avoid the manual management of errors rows.Close
scanning boilerplate.
db, _ := sql.Open("mysql", "user:password...")
query := "SELECT id, email, phone_number, status FROM users"
rows, err := db.Query(query)
if err != nil {
log.Fatal(err)
}
defer rows.Close()
// Loop through the rows and populate User structs
var users []User
for rows.Next() {
var user User
err := rows.Scan(&user.ID, &user.Email, &user.PhoneNumber, &user.Status)
if err != nil {
log.Fatal(err)
continue
}
users = append(users, user)
}
sqlx
builds on database/sql
to reduce scanning boilerplate. However, SQL generation is still nontrivial.
How would you modify the code below to support flexible filters? e.g.
- find all users with a status of
active
- find all users with a specific phone number and a specific email address
We wanted the nice scanning attributes with the power and flexibility of a query builder.
db, _ := sqlx.Open("mysql", "user:password...")
// Define your SQL query
query := "SELECT id, email, phone_number, status FROM users"
// Execute the query and retrieve users
var users []User
err = db.Select(&users, query)
if err != nil {
log.Fatal(err)
}
gorm
is a full-featured ORM library. That's great for some people and some projects!
gorm certainly does a great job of removing boilerplate around common DB IO.
That being said - some people are ORM people and some people aren't. If you value full control over what SQL is being run, a
query builder based approach is going to be friendlier than an ORM based approach.
var users []User
if err := db.Table("users").Find(&users).Error; err != nil {
log.Fatal(err)
}
sqx
uses [email protected]
in a docker file for development and testing. It is hardcoded to run on port 4306
Start it with
make services
and kill it with
make services-stop
Run all tests with
make tests