skeleton/internal/database/db.go

package database

//go:generate sh -c "rm -f *.xo.go"
//go:generate xo $DATABASE_DSN --escape-all --template-path templates/ --package database -o .
//go:generate sh -c "rm -f schemamigration.xo.go"
//go:generate

import (
	"database/sql"

	"github.com/jmoiron/sqlx"
	"github.com/lib/pq"
)

// New initializes a new postgres database connection pool
func New(dsn string) (*sqlx.DB, error) {
	conn, err := sqlx.Open("postgres", dsn)
	return conn, err
}

// IsErrNoRows returns true if the error indicates that no rows were
// returned from the database.
func IsErrNoRows(err error) bool {
	return err == sql.ErrNoRows
}

// IsErrUniqueViolation returns true if the error indicates that a UNIQUE
// constraint violation has occured.
func IsErrUniqueViolation(err error) bool {
	// see if we can cast the error to a Database error type
	pqErr, ok := err.(*pq.Error)
	if !ok {
		// Wrong error type
		return false
	}

	// check if error is "unique constraint violation"
	if pqErr.Code != "23505" {
		// if thats NOT the case, it's another error
		return false
	}
	return true
}

// IsErrForeignKeyViolation returns true if the error indicates that a
// FOREIGN KEY constraint has been violated due to the requested changes.
func IsErrForeignKeyViolation(err error) bool {
	// see if we can cast the error to a Database error type
	pqErr, ok := err.(*pq.Error)
	if !ok {
		// Wrong error type
		return false
	}

	// check if error is "foreign key violation"
	if pqErr.Code != "23503" {
		// if thats NOT the case, it's another error
		return false
	}
	return true
}