switch to mysql driver, separate pgx logic, handle no-change migration

db/mysql.go

@@ -0,0 +1,31 @@
+package db
+
+import (
+	"database/sql"
+	"log/slog"
+	"time"
+
+	_ "github.com/go-sql-driver/mysql"
+)
+
+const maxOpenDbConn = 10
+const maxIdleDbConn = 5
+const maxDbLifetime = time.Minute * 5
+
+func NewMySQL(dataSource string) (*sql.DB, error) {
+	d, err := sql.Open("mysql", dataSource)
+	if err != nil {
+		slog.Error("error connecting to database", "error", err)
+	}
+
+	d.SetMaxOpenConns(maxOpenDbConn)
+	d.SetMaxIdleConns(maxIdleDbConn)
+	d.SetConnMaxLifetime(maxDbLifetime)
+
+	if err := d.Ping(); err != nil {
+		slog.Error("error pinging database", "error", err)
+		return nil, err
+	}
+
+	return d, nil
+}