签入脚本

internal/migrate/conn.go

@@ -0,0 +1,114 @@
+package migrate
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/gogf/gf/v2/database/gdb"
+)
+
+// ============================== 数据库连接 ==============================
+
+// openConn 按 DSN 动态建立连接并探活
+//
+// 通过 gdb.New 注册独立命名节点，不触碰 config.yaml 中的默认连接
+func openConn(ctx context.Context, node string, dsn DSN) (gdb.DB, error) {
+	link, err := buildLink(dsn)
+	if err != nil {
+		return nil, err
+	}
+	db, err := gdb.New(gdb.ConfigNode{
+		Name: node,
+		Type: dsn.Type,
+		Link: link,
+	})
+	if err != nil {
+		return nil, fmt.Errorf("连接 %s 库失败: %v", node, err)
+	}
+	if _, err = db.Query(ctx, "SELECT 1"); err != nil {
+		return nil, fmt.Errorf("%s 库探活失败: %v", node, err)
+	}
+	return db, nil
+}
+
+// ensureDatabase 目标库不存在时先创建
+//
+// MySQL、PostgreSQL、SQL Server 经维护库建库；Oracle 与 SQLite 无需预建
+func ensureDatabase(ctx context.Context, dsn DSN) error {
+	var maintainDB, createSQL, checkSQL string
+	switch dsn.Type {
+	case "mysql":
+		maintainDB, checkSQL = "", "SELECT SCHEMA_NAME FROM information_schema.SCHEMATA WHERE SCHEMA_NAME = ?"
+		createSQL = "CREATE DATABASE `" + dsn.Database + "` CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci"
+	case "pgsql":
+		maintainDB, checkSQL = "postgres", "SELECT 1 FROM pg_database WHERE datname = ?"
+		createSQL = `CREATE DATABASE "` + dsn.Database + `"`
+	case "mssql":
+		maintainDB, checkSQL = "master", "SELECT 1 FROM sys.databases WHERE name = ?"
+		createSQL = "CREATE DATABASE [" + dsn.Database + "]"
+	default:
+		return nil // oracle/sqlite 无需预建
+	}
+	checkDSN := dsn
+	checkDSN.Database = maintainDB
+	link, err := buildLink(checkDSN)
+	if err != nil {
+		return err
+	}
+	maintain, err := gdb.New(gdb.ConfigNode{Name: "migrate_maintain", Type: dsn.Type, Link: link})
+	if err != nil {
+		return fmt.Errorf("连接 %s 维护库失败: %v", dsn.Type, err)
+	}
+	defer maintain.Close(ctx)
+	row, err := maintain.Query(ctx, checkSQL, dsn.Database)
+	if err != nil {
+		return fmt.Errorf("检查目标库是否存在失败: %v", err)
+	}
+	if len(row) > 0 {
+		return nil // 已存在
+	}
+	if _, err = maintain.Exec(ctx, createSQL); err != nil {
+		return fmt.Errorf("创建目标库 %s 失败: %v", dsn.Database, err)
+	}
+	return nil
+}
+
+// buildLink 将 DSN 转换为 gdb link 串
+//
+// 各方言按驱动约定格式组装，对齐配置示例
+func buildLink(dsn DSN) (string, error) {
+	switch dsn.Type {
+	case "mysql":
+		return fmt.Sprintf("%s:%s@tcp(%s:%s)/%s?charset=utf8mb4&parseTime=true&loc=Local",
+			dsn.Username, dsn.Password, dsn.Host, dsn.Port, dsn.Database), nil
+	case "pgsql":
+		return fmt.Sprintf("%s:%s@tcp(%s:%s)/%s?sslmode=disable",
+			dsn.Username, dsn.Password, dsn.Host, dsn.Port, dsn.Database), nil
+	case "mssql":
+		return fmt.Sprintf("%s:%s@tcp(%s:%s)/%s?encrypt=disable",
+			dsn.Username, dsn.Password, dsn.Host, dsn.Port, dsn.Database), nil
+	case "oracle":
+		return fmt.Sprintf("%s:%s@tcp(%s:%s)/%s",
+			dsn.Username, dsn.Password, dsn.Host, dsn.Port, dsn.Database), nil
+	case "sqlite":
+		if dsn.Database == "" {
+			return "", fmt.Errorf("sqlite 需以 -src-database/-dst-database 指定数据库文件路径")
+		}
+		return fmt.Sprintf("sqlite::@file(%s)", dsn.Database), nil
+	}
+	return "", fmt.Errorf("不支持的数据库类型: %s", dsn.Type)
+}
+
+// tableExists 判断目标库中同名表是否已存在
+func tableExists(ctx context.Context, db gdb.DB, table string) (bool, error) {
+	tables, err := db.Tables(ctx)
+	if err != nil {
+		return false, err
+	}
+	for _, t := range tables {
+		if t == table {
+			return true, nil
+		}
+	}
+	return false, nil
+}