database.go

@@ -1,11 +1,8 @@
 package dbschema
 
 import (
-	// External
-	"github.com/jackc/pgx/v5/pgxpool"
-
 	// Standard
-	"context"
+	"database/sql"
 	"fmt"
 )
 
@@ -16,21 +13,17 @@ func newDatabase(host string, port int, dbName, user, pass string) (dbase Databa
 	dbase.Username = user
 	dbase.Password = pass
 
-	dbase.db, err = pgxpool.New(context.Background(), dbase.sqlConnString())
+	dbase.db, err = sql.Open("postgres", dbase.sqlConnString())
 	return
 }// }}}
-func databaseFromInstance(db *pgxpool.Pool) (dbase Database, err error) {
-	dbase.db = db
-	return
-}
 
 func (dbase Database) sqlConnString() string {// {{{
 	return fmt.Sprintf(
-		"host=%s port=%d user=%s password=%s dbname=%s sslmode=disable",
-		dbase.Host,
-		dbase.Port,
+		"postgresql://%s:%s@%s:%d/%s?sslmode=disable",
 		dbase.Username,
 		dbase.Password,
+		dbase.Host,
+		dbase.Port,
 		dbase.DbName,
 	)
 }// }}}

schema.go

@@ -21,13 +21,15 @@ package dbschema
 
 import (
 	// External
-	"github.com/jackc/pgx/v5/pgxpool"
+	_ "github.com/lib/pq"
+
+	// Standard
+	"database/sql"
 )
 
 // An upgrader verifies the schema for one or more databases and upgrades them if possible.
 type Upgrader struct {
-	schema      string
-	databases   map[string]Database
+	databases map[string]Database
 	logCallback func(string, string)
 	sqlCallback func(string, int) ([]byte, bool)
 }
@@ -39,7 +41,7 @@ type Database struct {
 	Username string
 	Password string
 
-	db       *pgxpool.Pool
+	db *sql.DB
 	upgrader *Upgrader
 }
 

upgrader.go

@@ -2,67 +2,46 @@ package dbschema
 
 import (
 	// External
-	"github.com/jackc/pgx/v5"
-	"github.com/jackc/pgx/v5/pgconn"
-	"github.com/jackc/pgx/v5/pgxpool"
+	"github.com/lib/pq"
 
 	// Standard
-	"context"
+	"database/sql"
 	"fmt"
 )
 
-func defaultCallback(topic, msg string) { // {{{
+func defaultCallback(topic, msg string) {// {{{
 	fmt.Printf("[%s] %s\n", topic, msg)
-} // }}}
+}// }}}
 
 // NewUpgrader creates an upgrader with an empty list of databases.
-func NewUpgrader(schema ...string) (upgrader Upgrader) { // {{{
-	// Using a variadic function for backward compatibility.
-	if len(schema) > 0 {
-		upgrader.schema = schema[0]
-	} else {
-		upgrader.schema = "_db"
-	}
-
+func NewUpgrader() (upgrader Upgrader) {// {{{
 	upgrader.logCallback = defaultCallback
 	upgrader.databases = map[string]Database{}
 	return
-} // }}}
+}// }}}
 
 // SetLogCallback allows to set a callback for custom logging.
-func (upgrader *Upgrader) SetLogCallback(callback func(string, string)) { // {{{
+func (upgrader *Upgrader) SetLogCallback(callback func(string, string)) {// {{{
 	upgrader.logCallback = callback
-} // }}}
+}// }}}
 // SetSqlCallback is required for providing the SQL schema updates.
-func (upgrader *Upgrader) SetSqlCallback(callback func(string, int) ([]byte, bool)) { // {{{
+func (upgrader *Upgrader) SetSqlCallback(callback func(string, int) ([]byte, bool)) {// {{{
 	upgrader.sqlCallback = callback
-} // }}}
-// Version returns the current dbschema version for the given database name.
-func (upgrader *Upgrader) Version(dbName string) (version int, err error) { // {{{
-	dbase, found := upgrader.databases[dbName]
-	if !found {
-		err = fmt.Errorf("Database %s not previously added to the upgrader", dbName)
-		return
-	}
+}// }}}
 
-	version, err = dbase.Version()
-	return
-} // }}}
-
-func (dbase Database) createSchemaTable() (err error) { // {{{
-	dbase.upgrader.logCallback("create", fmt.Sprintf("%s, %s.schema", dbase.DbName, dbase.upgrader.schema))
-	_, err = dbase.db.Exec(context.Background(), `CREATE SCHEMA "` + dbase.upgrader.schema + `"`)
+func (dbase Database) createSchemaTable() (err error) {// {{{
+	dbase.upgrader.logCallback("create", fmt.Sprintf("%s, _db.schema", dbase.DbName))
+	_, err = dbase.db.Exec(`CREATE SCHEMA "_db"`)
 
 	// Error code 42P06 "duplicate_schema" is an OK error,
 	// table can still be missing and created.
-	pqErr, _ := err.(*pgconn.PgError)
+	pqErr, _ := err.(*pq.Error)
 	if pqErr != nil && pqErr.Code != "42P06" {
 		return
 	}
 
-	_, err = dbase.db.Exec(
-		context.Background(),
-		`CREATE TABLE "` + dbase.upgrader.schema + `"."schema" (
+	_, err = dbase.db.Exec(`
+		CREATE TABLE "_db"."schema" (
 			version  int4      NOT NULL,
 			updated  timestamp NOT NULL DEFAULT NOW(),
 
@@ -70,20 +49,19 @@ func (dbase Database) createSchemaTable() (err error) { // {{{
 		)`,
 	)
 	return
-} // }}}
-func (dbase Database) appendSchemaVersion(version int) (err error) { // {{{
-	_, err = dbase.db.Exec(context.Background(), `INSERT INTO `+dbase.upgrader.schema+`.schema(version) VALUES($1)`, version)
+}// }}}
+func (dbase Database) appendSchemaVersion(version int) (err error) {// {{{
+	_, err = dbase.db.Exec(`INSERT INTO _db.schema(version) VALUES($1)`, version)
 	return
-} // }}}
+}// }}}
 
-func (dbase Database) verifySchemaTable() (err error) { // {{{
-	var rows pgx.Rows
+func (dbase Database) verifySchemaTable() (err error) {// {{{
+	var rows *sql.Rows
 	if rows, err = dbase.db.Query(
-		context.Background(),
 		`SELECT EXISTS (
 			SELECT FROM pg_catalog.pg_class c
 			JOIN   pg_catalog.pg_namespace n ON n.oid = c.relnamespace
-			WHERE  n.nspname = '` + dbase.upgrader.schema + `'
+			WHERE  n.nspname = '_db'
 			AND    c.relname = 'schema'
 		)`,
 	); err != nil {
@@ -101,25 +79,24 @@ func (dbase Database) verifySchemaTable() (err error) { // {{{
 	}
 	err = dbase.createSchemaTable()
 	return
-} // }}}
-func (dbase Database) verifySchemaEntry() (err error) { // {{{
+}// }}}
+func (dbase Database) verifySchemaEntry() (err error) {// {{{
 	var version int
-	var row pgx.Row
-	row = dbase.db.QueryRow(context.Background(), `SELECT version FROM `+dbase.upgrader.schema+`.schema LIMIT 1`)
+	var row *sql.Row
+	row = dbase.db.QueryRow(`SELECT version FROM _db.schema LIMIT 1`)
 
 	err = row.Scan(&version)
-	if err == pgx.ErrNoRows {
+	if err == sql.ErrNoRows {
 		dbase.upgrader.logCallback("initiate version", dbase.DbName)
 		err = dbase.appendSchemaVersion(0)
 	}
 
 	return
-} // }}}
-func (dbase Database) Version() (version int, err error) { // {{{
-	var rows pgx.Rows
+}// }}}
+func (dbase Database) version() (version int, err error) {// {{{
+	var rows *sql.Rows
 	rows, err = dbase.db.Query(
-		context.Background(),
-		`SELECT version FROM ` + dbase.upgrader.schema + `.schema ORDER BY version DESC LIMIT 1`,
+		`SELECT version FROM _db.schema ORDER BY version DESC LIMIT 1`,
 	)
 	if err != nil {
 		return
@@ -129,13 +106,14 @@ func (dbase Database) Version() (version int, err error) { // {{{
 	if rows.Next() {
 		err = rows.Scan(&version)
 	} else {
-		err = fmt.Errorf(`Database "%s" is missing an entry in `+dbase.upgrader.schema+`.schema`, dbase.DbName)
+		err = fmt.Errorf(`Database "%s" is missing an entry in _db.schema`, dbase.DbName)
 	}
 	return
-} // }}}
+}// }}}
 
 // AddDatabase sets a database up for the Run() function with verifying/creating the _db.schema table.
-func (upgrader Upgrader) AddDatabase(host string, port int, dbName, user, pass string) (db Database, err error) { // {{{
+func (upgrader Upgrader) AddDatabase(host string, port int, dbName, user, pass string) (err error) {// {{{
+	var db Database
 	if db, err = newDatabase(host, port, dbName, user, pass); err != nil {
 		return
 	}
@@ -149,32 +127,17 @@ func (upgrader Upgrader) AddDatabase(host string, port int, dbName, user, pass s
 
 	err = db.verifySchemaEntry()
 	return
-} // }}}
-func (upgrader Upgrader) AddDatabaseInstance(sqlDB *pgxpool.Pool, dbName string) (db Database, err error) { // {{{
-	db, err = databaseFromInstance(sqlDB)
-
-	db.upgrader = &upgrader
-
-	upgrader.databases[dbName] = db
-
-	if err = db.verifySchemaTable(); err != nil {
-		return
-	}
-
-	err = db.verifySchemaEntry()
-	return
-} // }}}
-
+}// }}}
 // Run executes the actual schema updates until there are no more available.
-func (upgrader Upgrader) Run() (err error) { // {{{
+func (upgrader Upgrader) Run() (err error) {// {{{
 	var version int
 
 	for dbName, dbase := range upgrader.databases {
-		version, err = dbase.Version()
+		version, err = dbase.version()
 		if err != nil {
 			return
 		}
-		upgrader.logCallback("version", fmt.Sprintf("%s.%s: %d", dbName, upgrader.schema, version))
+		upgrader.logCallback("version", fmt.Sprintf("%s: %d", dbName, version))
 
 		for {
 			version++
@@ -183,8 +146,8 @@ func (upgrader Upgrader) Run() (err error) { // {{{
 				break
 			}
 
-			upgrader.logCallback("exec", fmt.Sprintf("%s.%s: %d", dbName, upgrader.schema, version))
-			if _, err = dbase.db.Exec(context.Background(), string(sql)); err != nil {
+			upgrader.logCallback("exec", fmt.Sprintf("%s: %d", dbName, version))
+			if _, err = dbase.db.Exec(string(sql)); err != nil {
 				return
 			}
 			if err = dbase.appendSchemaVersion(version); err != nil {
@@ -193,6 +156,6 @@ func (upgrader Upgrader) Run() (err error) { // {{{
 		}
 	}
 	return
-} // }}}
+}// }}}
 
 // vim: foldmethod=marker