mysql: create database now distinct from create tables

Because we do not want the database name to be optional with a
placeholder (/*DB*/) in the statement that creates the database, since
it is not actually optional there - as opposed to when creating tables.

Change-Id: I05351d76d95071492d763758a11454f219524510

cmd/camtool/dbinit.go

@@ -169,9 +169,11 @@ func (c *dbinitCmd) RunCommand(args []string) error {
 		}
 		doQuery(db, fmt.Sprintf(`SELECT replaceintometa('version', '%d')`, postgres.SchemaVersion()))
 	case "mysql":
-		for _, tableSql := range mysql.SQLCreateTables() {
-			tableSql = strings.Replace(tableSql, "/*DB*/", dbname, -1)
-			do(db, tableSql)
+		if err := mysql.CreateDB(db, dbname); err != nil {
+			exitf("%v", err)
+		}
+		for _, tableSQL := range mysql.SQLCreateTables() {
+			do(db, tableSQL)
 		}
 		do(db, fmt.Sprintf(`REPLACE INTO meta VALUES ('version', '%d')`, mysql.SchemaVersion()))
 	case "sqlite":

pkg/sorted/mysql/dbschema.go

@@ -28,7 +28,6 @@ func SchemaVersion() int {
 // which is purely about bytes.
 func SQLCreateTables() []string {
 	return []string{
-		`CREATE DATABASE IF NOT EXISTS /*DB*/`,
 		`CREATE TABLE IF NOT EXISTS /*DB*/.rows (
  k VARCHAR(255) NOT NULL PRIMARY KEY,
  v VARCHAR(255))

pkg/sorted/mysql/mysqlkv.go

@@ -20,6 +20,7 @@ package mysql
 
 import (
 	"database/sql"
+	"errors"
 	"fmt"
 	"os"
 	"strings"
@@ -68,6 +69,9 @@ func newKeyValueFromJSONConfig(cfg jsonconfig.Obj) (sorted.KeyValue, error) {
 		return nil, err
 	}
 
+	if err := CreateDB(db, database); err != nil {
+		return nil, err
+	}
 	for _, tableSQL := range SQLCreateTables() {
 		tableSQL = strings.Replace(tableSQL, "/*DB*/", database, -1)
 		if _, err := db.Exec(tableSQL); err != nil {
@@ -108,6 +112,17 @@ func newKeyValueFromJSONConfig(cfg jsonconfig.Obj) (sorted.KeyValue, error) {
 	return kv, nil
 }
 
+// CreateDB creates the named database if it does not already exist.
+func CreateDB(db *sql.DB, dbname string) error {
+	if dbname == "" {
+		return errors.New("can not create database: database name is missing")
+	}
+	if _, err := db.Exec(fmt.Sprintf("CREATE DATABASE IF NOT EXISTS %s", dbname)); err != nil {
+		return fmt.Errorf("error creating database %v: %v", dbname, err)
+	}
+	return nil
+}
+
 // We keep a cache of open database handles.
 var (
 	dbsmu sync.Mutex