/
db.go
91 lines (80 loc) · 2.34 KB
/
db.go
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package runner
import (
"database/sql"
"github.com/jmoiron/sqlx"
"gopkg.in/mgutz/dat.v1"
)
// DB represents an abstract database connection pool.
type DB struct {
DB *sqlx.DB
*Queryable
Version int64
}
var standardConformingStrings string
// pgMustNotAllowEscapeSequence checks if Postgres treats backlashes
// literally in strings when dat.EnableInterpolation == true. If escape
// sequences are allowed, then it is unsafe to use interpolation and
// this function panics.
func pgMustNotAllowEscapeSequence(conn *DB) {
if !dat.EnableInterpolation {
return
}
if standardConformingStrings == "" {
err := conn.
SQL("select setting from pg_settings where name='standard_conforming_strings'").
QueryScalar(&standardConformingStrings)
if err != nil {
panic(err)
}
}
if standardConformingStrings != "on" {
logger.Fatal("Database allows escape sequences. Cannot be used with interpolation. "+
"standard_conforming_strings=%q\n"+
"See http://www.postgresql.org/docs/9.3/interactive/sql-syntax-lexical.html#SQL-SYNTAX-STRINGS-ESCAPE",
"standardConformingStrings", standardConformingStrings)
}
}
func pgSetVersion(db *DB) {
err := db.
SQL("SHOW server_version_num").
QueryScalar(&db.Version)
if err != nil {
logger.Fatal("Could not query Postgres version")
return
}
}
// NewDB instantiates a Connection for a given database/sql connection
func NewDB(db *sql.DB, driverName string) *DB {
database := sqlx.NewDb(db, driverName)
conn := &DB{DB: database, Queryable: &Queryable{database}}
if driverName == "postgres" {
pgMustNotAllowEscapeSequence(conn)
pgSetVersion(conn)
if dat.Strict {
conn.SQL("SET client_min_messages to 'DEBUG';")
}
} else {
panic("Unsupported driver: " + driverName)
}
return conn
}
// NewDBFromString instantiates a Connection from a given driver
// and connection string.
func NewDBFromString(driver string, connectionString string) *DB {
db, err := sql.Open(driver, connectionString)
if err != nil {
logger.Fatal("Database error ", "err", err)
}
err = db.Ping()
if err != nil {
logger.Fatal("Could not ping database", "err", err)
}
return NewDB(db, driver)
}
// NewDBFromSqlx creates a new Connection object from existing Sqlx.DB.
func NewDBFromSqlx(dbx *sqlx.DB) *DB {
conn := &DB{DB: dbx, Queryable: &Queryable{dbx}}
pgMustNotAllowEscapeSequence(conn)
pgSetVersion(conn)
return conn
}