sqlx README

The project's README from github.com/jmoiron/sqlx. As one markdown file: README.md.

sqlx

CircleCI Coverage Status Godoc license

sqlx is a library which provides a set of extensions on go's standard database/sql library. The sqlx versions of sql.DB, sql.TX, sql.Stmt, et al. all leave the underlying interfaces untouched, so that their interfaces are a superset on the standard ones. This makes it relatively painless to integrate existing codebases using database/sql with sqlx.

Major additional concepts are:

In addition to the godoc API documentation, there is also some user documentation that explains how to use database/sql along with sqlx.

Recent Changes

1.3.0:

DB.Connx returns an sqlx.Conn, which is an sql.Conn-alike consistent with sqlx's wrapping of other types.

BindDriver allows users to control the bindvars that sqlx will use for drivers, and add new drivers at runtime. This results in a very slight performance hit when resolving the driver into a bind type (~40ns per call), but it allows users to specify what bindtype their driver uses even when sqlx has not been updated to know about it by default.

Backwards Compatibility

Compatibility with the most recent two versions of Go is a requirement for any new changes. Compatibility beyond that is not guaranteed.

Versioning is done with Go modules. Breaking changes (eg. removing deprecated API) will get major version number bumps.

install

go get github.com/jmoiron/sqlx

issues

Row headers can be ambiguous (SELECT 1 AS a, 2 AS a), and the result of Columns() does not fully qualify column names in queries like:

SELECT a.id, a.name, b.id, b.name FROM foos AS a JOIN foos AS b ON a.parent = b.id;

making a struct or map destination ambiguous. Use AS in your queries to give columns distinct names, rows.Scan to scan them manually, or SliceScan to get a slice of results.

usage

Below is an example which shows some common use cases for sqlx. Check sqlx_test.go for more usage.

package main

import (
    "database/sql"
    "fmt"
    "log"
    
    _ "github.com/lib/pq"
    "github.com/jmoiron/sqlx"
)

var schema = `
CREATE TABLE person (
    first_name text,
    last_name text,
    email text
);

CREATE TABLE place (
    country text,
    city text NULL,
    telcode integer
)`

type Person struct {
    FirstName string `db:"first_name"`
    LastName  string `db:"last_name"`
    Email     string
}

type Place struct {
    Country string
    City    sql.NullString
    TelCode int
}

func main() {
    // this Pings the database trying to connect
    // use sqlx.Open() for sql.Open() semantics
    db, err := sqlx.Connect("postgres", "user=foo dbname=bar sslmode=disable")
    if err != nil {
        log.Fatalln(err)
    }

    // exec the schema or fail; multi-statement Exec behavior varies between
    // database drivers;  pq will exec them all, sqlite3 won't, ymmv
    db.MustExec(schema)
    
    tx := db.MustBegin()
    tx.MustExec("INSERT INTO person (first_name, last_name, email) VALUES ($1, $2, $3)", "Jason", "Moiron", "[email protected]")
    tx.MustExec("INSERT INTO person (first_name, last_name, email) VALUES ($1, $2, $3)", "John", "Doe", "[email protected]")
    tx.MustExec("INSERT INTO place (country, city, telcode) VALUES ($1, $2, $3)", "United States", "New York", "1")
    tx.MustExec("INSERT INTO place (country, telcode) VALUES ($1, $2)", "Hong Kong", "852")
    tx.MustExec("INSERT INTO place (country, telcode) VALUES ($1, $2)", "Singapore", "65")
    // Named queries can use structs, so if you have an existing struct (i.e. person := &Person{}) that you have populated, you can pass it in as &person
    tx.NamedExec("INSERT INTO person (first_name, last_name, email) VALUES (:first_name, :last_name, :email)", &Person{"Jane", "Citizen", "[email protected]"})
    tx.Commit()

    // Query the database, storing results in a []Person (wrapped in []interface{})
    people := []Person{}
    db.Select(&people, "SELECT * FROM person ORDER BY first_name ASC")
    jason, john := people[0], people[1]

    fmt.Printf("%#v\n%#v", jason, john)
    // Person{FirstName:"Jason", LastName:"Moiron", Email:"[email protected]"}
    // Person{FirstName:"John", LastName:"Doe", Email:"[email protected]"}

    // You can also get a single result, a la QueryRow
    jason = Person{}
    err = db.Get(&jason, "SELECT * FROM person WHERE first_name=$1", "Jason")
    fmt.Printf("%#v\n", jason)
    // Person{FirstName:"Jason", LastName:"Moiron", Email:"[email protected]"}

    // if you have null fields and use SELECT *, you must use sql.Null* in your struct
    places := []Place{}
    err = db.Select(&places, "SELECT * FROM place ORDER BY telcode ASC")
    if err != nil {
        fmt.Println(err)
        return
    }
    usa, singsing, honkers := places[0], places[1], places[2]
    
    fmt.Printf("%#v\n%#v\n%#v\n", usa, singsing, honkers)
    // Place{Country:"United States", City:sql.NullString{String:"New York", Valid:true}, TelCode:1}
    // Place{Country:"Singapore", City:sql.NullString{String:"", Valid:false}, TelCode:65}
    // Place{Country:"Hong Kong", City:sql.NullString{String:"", Valid:false}, TelCode:852}

    // Loop through rows using only one struct
    place := Place{}
    rows, err := db.Queryx("SELECT * FROM place")
    for rows.Next() {
        err := rows.StructScan(&place)
        if err != nil {
            log.Fatalln(err)
        } 
        fmt.Printf("%#v\n", place)
    }
    // Place{Country:"United States", City:sql.NullString{String:"New York", Valid:true}, TelCode:1}
    // Place{Country:"Hong Kong", City:sql.NullString{String:"", Valid:false}, TelCode:852}
    // Place{Country:"Singapore", City:sql.NullString{String:"", Valid:false}, TelCode:65}

    // Named queries, using `:name` as the bindvar.  Automatic bindvar support
    // which takes into account the dbtype based on the driverName on sqlx.Open/Connect
    _, err = db.NamedExec(`INSERT INTO person (first_name,last_name,email) VALUES (:first,:last,:email)`, 
        map[string]interface{}{
            "first": "Bin",
            "last": "Smuth",
            "email": "[email protected]",
    })

    // Selects Mr. Smith from the database
    rows, err = db.NamedQuery(`SELECT * FROM person WHERE first_name=:fn`, map[string]interface{}{"fn": "Bin"})

    // Named queries can also use structs.  Their bind names follow the same rules
    // as the name -> db mapping, so struct fields are lowercased and the `db` tag
    // is taken into consideration.
    rows, err = db.NamedQuery(`SELECT * FROM person WHERE first_name=:first_name`, jason)
    
    
    // batch insert
    
    // batch insert with structs
    personStructs := []Person{
        {FirstName: "Ardie", LastName: "Savea", Email: "[email protected]"},
        {FirstName: "Sonny Bill", LastName: "Williams", Email: "[email protected]"},
        {FirstName: "Ngani", LastName: "Laumape", Email: "[email protected]"},
    }

    _, err = db.NamedExec(`INSERT INTO person (first_name, last_name, email)
        VALUES (:first_name, :last_name, :email)`, personStructs)

    // batch insert with maps
    personMaps := []map[string]interface{}{
        {"first_name": "Ardie", "last_name": "Savea", "email": "[email protected]"},
        {"first_name": "Sonny Bill", "last_name": "Williams", "email": "[email protected]"},
        {"first_name": "Ngani", "last_name": "Laumape", "email": "[email protected]"},
    }

    _, err = db.NamedExec(`INSERT INTO person (first_name, last_name, email)
        VALUES (:first_name, :last_name, :email)`, personMaps)
}

sqlx (jmoiron/sqlx)

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17.7K ·GitHub
Sqlx
What is this?sqlx is a Go library that extends the standard database/sql package with higher-level conveniences, so you write less boilerplate around queries and rows.
How is it different from just using database/sql?It is a thin layer on top, not a replacement: sqlx.DB, sqlx.TX and sqlx.Stmt keep the standard interfaces untouched, so their methods are a superset and existing database/sql code mixes in painlessly.
How do I add it to a project?Run 'go get github.com/jmoiron/sqlx' — versioning is done with Go modules, so adding it to go.mod is all the setup there is.
Which databases does it work with?Any database that has a database/sql driver, since sqlx only wraps the standard types. BindDriver additionally lets you register the bindvar syntax of drivers sqlx does not know yet, at runtime.
What happens if a query returns two columns with the same name?Mapping becomes ambiguous, because Columns() does not fully qualify column names and struct or map destinations can be unclear. Use AS to give columns distinct names, scan rows manually, or take SliceScan to get a slice.
What can it do that plain database/sql can't?Its headline additions: marshal rows into structs, including embedded structs, as well as into maps and slices; named parameter support including prepared statements; and Get and Select to go from query to struct or slice quickly.
Is there a performance cost to using it?Essentially none. The only cost called out is roughly 40ns per call when BindDriver resolves a driver's bind type at runtime, and version 1.3.0 even brought allocation and performance improvements to sqlx.In.
Will upgrading Go or sqlx itself break my code?Backwards compatibility is a stated requirement: every change must keep working with the two most recent Go versions, versioning is done with Go modules, and breaking changes like removing deprecated API get a major version bump.
What are similar projects?pgx, postgres, sequelize, mybatis-3, go, Dapper, usql, rqlite
Which topics is it in?relational-database, makefile, mit-license, sql, utility, developers, backend, database, go, free, library, developer-tools
Creator
jmoiron
Size
0.9 MB
Stars
17.7K
Updated
CommitMay 30Releasev1.4.0Apr 23
Age
13y
Commits · 90 Days