/
pg.go
269 lines (219 loc) · 6.83 KB
/
pg.go
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package pgdb
import (
"fmt"
"github.com/go-pg/pg/v9"
"github.com/go-pg/pg/v9/orm"
"github.com/vanclief/ez"
"github.com/vanclief/state/interfaces"
)
const (
// ETABLEEXISTS happens when a table already exists
ETABLEEXISTS = "ERROR #42P07"
// ENOROWS happens when no result was found
ENOROWS = "pg: no rows in result set"
// EMULTIPLEROWS happens when multiple results where found with QueryOne
EMULTIPLEROWS = "pg: multiple rows in result set"
)
// DB defines a PostgreSQL database that will use go-pg as an ORM
type DB struct {
pg *pg.DB
}
// New returns a new PG Database instance
func New(address string, user string, password string, database string) (*DB, error) {
db := pg.Connect(&pg.Options{
Addr: address,
User: user,
Password: password,
Database: database,
})
_, err := db.Exec("SELECT 1")
if err != nil {
db.Close()
return nil, err
}
return &DB{pg: db}, nil
}
// NewFromURL returns a new PG Database instance
func NewFromURL(url string) (*DB, error) {
opt, err := pg.ParseURL(url)
if err != nil {
panic(err)
}
db := pg.Connect(opt)
_, err = db.Exec("SELECT 1")
if err != nil {
db.Close()
return nil, err
}
return &DB{pg: db}, nil
}
// Get returns a single model from the database using its primary key
func (db *DB) Get(m interfaces.Model, ID interface{}) error {
const op = "PG.DB.Get"
switch ID.(type) {
case string:
case []byte:
default:
return ez.New(op, ez.EINVALID, "Can not use provided ID interface type", nil)
}
query := fmt.Sprintf(`SELECT * FROM %s WHERE %s = ?`, m.GetSchema().Name, m.GetSchema().PKey)
res, err := db.pg.QueryOne(m, query, ID)
if res != nil && res.RowsReturned() < 1 {
msg := fmt.Sprintf("Could not find a %s model with id %s", m.GetSchema().Name, ID)
return ez.New(op, ez.ENOTFOUND, msg, nil)
}
if err != nil {
switch err.Error() {
case ENOROWS:
msg := fmt.Sprintf("Could not find a %s model with id %s", m.GetSchema().Name, ID)
return ez.New(op, ez.ENOTFOUND, msg, nil)
default:
return ez.New(op, ez.EINTERNAL, "Error making query to the database", err)
}
}
return nil
}
// QueryOne returns a single model from the database that satisfies a Query.
// The method will return an error if there is more than one result from the query
func (db *DB) QueryOne(m interfaces.Model, query string) error {
const op = "PG.DB.QueryOne"
q := fmt.Sprintf(`SELECT * FROM %s WHERE %s`, m.GetSchema().Name, query)
_, err := db.pg.QueryOne(m, q, nil)
if err != nil {
switch err.Error() {
case ENOROWS:
msg := fmt.Sprintf("Could not find a %s model with query %s", m.GetSchema().Name, query)
return ez.New(op, ez.ENOTFOUND, msg, nil)
case EMULTIPLEROWS:
msg := fmt.Sprintf("Could find multiple %s models that satisfy QueryOne %s", m.GetSchema().Name, query)
return ez.New(op, ez.ECONFLICT, msg, nil)
default:
return ez.New(op, ez.EINTERNAL, "Error making query to the database", err)
}
}
return nil
}
// Query returns a list of models from the database that satisfy a Query, extra parameters
// in the Query allow for Limit and Offset
func (db *DB) Query(mList interface{}, model interfaces.Model, query []string) error {
const op = "PG.DB.Query"
var q string
switch len(query) {
case 1:
q = fmt.Sprintf(`SELECT * FROM %s WHERE %s`, model.GetSchema().Name, query[0])
case 2:
q = fmt.Sprintf(`SELECT * FROM %s WHERE %s LIMIT %s`, model.GetSchema().Name, query[0], query[1])
default:
q = fmt.Sprintf(`SELECT * FROM %s WHERE %s LIMIT %s OFFSET %s`, model.GetSchema().Name, query[0], query[1], query[2])
}
result, err := db.pg.Query(mList, q, nil)
if err != nil || result == nil {
switch err.Error() {
case ENOROWS:
msg := fmt.Sprintf("Could not find a %s model with query %s", model.GetSchema().Name, query)
return ez.New(op, ez.ENOTFOUND, msg, nil)
default:
return ez.New(op, ez.EINTERNAL, "Error making query to the database", err)
}
}
if result.RowsReturned() == 0 {
msg := fmt.Sprintf("Could not find any %s with query %s", model.GetSchema().Name, q)
return ez.New(op, ez.ENOTFOUND, msg, nil)
}
return nil
}
// RawQuery returns a list of models from the database that satisfy a Raw Query
func (db *DB) RawQuery(mList interface{}, model interfaces.Model, rawQuery []string) error {
const op = "PG.DB.RawQuery"
result, err := db.pg.Query(mList, rawQuery, nil)
if err != nil || result == nil {
switch err.Error() {
default:
return ez.New(op, ez.EINTERNAL, "Error making query to the database", err)
}
}
if result.RowsReturned() == 0 {
msg := fmt.Sprintf("Could not find any %s with query %s", model.GetSchema().Name, rawQuery)
return ez.New(op, ez.ENOTFOUND, msg, nil)
}
return nil
}
// Insert adds a model into the database
func (db *DB) Insert(m interfaces.Model) error {
const op = "PG.DB.Insert"
err := db.pg.Insert(m)
if err != nil {
switch err.Error() {
default:
errMsg := fmt.Sprintf("Error inserting %s into %s", m.GetID(), m.GetSchema().Name)
return ez.New(op, ez.EINTERNAL, errMsg, err)
}
}
return nil
}
// Update changes an existing model from the database
func (db *DB) Update(m interfaces.Model) error {
const op = "PG.DB.Update"
err := db.pg.Update(m)
if err != nil {
switch err.Error() {
default:
errMsg := fmt.Sprintf("Error updating %s from %s", m.GetID(), m.GetSchema().Name)
return ez.New(op, ez.EINTERNAL, errMsg, err)
}
}
return nil
}
// Delete removes an existing model from the database
func (db *DB) Delete(m interfaces.Model) error {
const op = "PG.DB.Delete"
err := db.pg.Delete(m)
if err != nil {
switch err.Error() {
default:
errMsg := fmt.Sprintf("Error deleting %s from %s", m.GetID(), m.GetSchema().Name)
return ez.New(op, ez.EINTERNAL, errMsg, err)
}
}
return nil
}
// CreateSchema creates the database tables if dropExisting is set to true it will drop the current schema
func (db *DB) CreateSchema(modelsList []interface{}, dropExisting bool) error {
const op = "PG.DB.CreateSchema"
for _, model := range modelsList {
if dropExisting {
err := db.DropTable(model)
if err != nil {
return ez.New(op, ez.ErrorCode(err), ez.ErrorMessage(err), err)
}
}
err := db.CreateTable(model)
if err != nil {
return ez.New(op, ez.ErrorCode(err), ez.ErrorMessage(err), err)
}
}
return nil
}
// CreateTable creates a new table in the database
func (db *DB) CreateTable(model interface{}) error {
const op = "PG.DB.CreateTable"
err := db.pg.CreateTable(model, &orm.CreateTableOptions{
Temp: false,
})
if err != nil {
errorCode := err.Error()[0:12]
if errorCode != ETABLEEXISTS {
return ez.New(op, ez.EINTERNAL, "Could not create table", err)
}
}
return nil
}
// DropTable deletes the existing tables
func (db *DB) DropTable(model interface{}) error {
const op = "PG.DB.DropTable"
err := db.pg.DropTable(model, &orm.DropTableOptions{})
if err != nil {
return ez.New(op, ez.EINTERNAL, "Could not drop table", err)
}
return nil
}