config構造体&読み込み処理、DB接続処理を実装

internal/database/database.go

@@ -0,0 +1,40 @@
+import (
+    "database/sql"
+    "fmt"
+    _ "github.com/go-sql-driver/mysql"
+    _ "github.com/mattn/go-sqlite3"
+)
+
+type Database struct {
+    *sql.DB
+}
+
+func NewDatabase(config *Config) (*Database, error) {
+    var dsn string
+    if config.DB.Type == "mysql" {
+        dsn = fmt.Sprintf("%s:%s@tcp(%s:%d)/%s?charset=utf8mb4&parseTime=True&loc=Local",
+            config.DB.User, config.DB.Password, config.DB.Host, config.DB.Port, config.DB.Name)
+    } else if config.DB.Type == "sqlite" {
+        dsn = config.DB.Name + ".db"
+    } else {
+        return nil, fmt.Errorf("unsupported database type: %s", config.DB.Type)
+    }
+
+    db, err := sql.Open(config.DB.Type, dsn)
+    if err != nil {
+        return nil, err
+    }
+
+    if err := db.Ping(); err != nil {
+        return nil, err
+    }
+	
+    db.SetMaxOpenConns(25)
+    db.SetMaxIdleConns(25)
+
+    return &Database{DB: db}, nil
+}
+
+func (d *Database) Close() error {
+    return d.DB.Close()
+}