feat: 新增 DuckDB 方言支持及 SQLite3 自动注册 IF 函数

- 新增 dialect/duckdb 方言，支持 DuckDB SQL 语法
- 新增 schema/dialect/duckdb DDL 操作支持
- dialect/sqlite3: 注册 sqlite3_with_if 驱动，连接时自动注册 IF() 函数
- engine: MakeConnection 对 sqlite3 自动使用带 IF 支持的驱动
- engine: 新增 DBConfig DuckDB 配置项及相关 Option 函数
- 统一各方言测试引用路径

engine/engine_config_test.go

@@ -5,9 +5,6 @@ import (
 	"time"
 
 	"git.fsdpf.net/go/db/engine"
-	_ "github.com/denisenkom/go-mssqldb"
-	_ "github.com/go-sql-driver/mysql"
-	_ "github.com/mattn/go-sqlite3"
 )
 
 // TestMySQLConfig 测试 MySQL 驱动的配置
@@ -59,7 +56,7 @@ func TestMySQLConfig(t *testing.T) {
 				engine.WithSQLServerInstance("SQLEXPRESS"),
 			},
 			wantErr: true,
-			errMsg:  "engine.WithSQLServerInstance is only valid for sqlserver driver",
+			errMsg:  "WithSQLServerInstance is only valid for sqlserver driver",
 		},
 	}
 
@@ -124,7 +121,7 @@ func TestPostgreSQLConfig(t *testing.T) {
 				engine.WithMySQLCollation("utf8mb4_unicode_ci"),
 			},
 			wantErr: true,
-			errMsg:  "engine.WithMySQLCollation is only valid for mysql driver",
+			errMsg:  "WithMySQLCollation is only valid for mysql driver",
 		},
 	}
 
@@ -179,7 +176,7 @@ func TestSQLiteConfig(t *testing.T) {
 				engine.WithPgSslmode("disable"),
 			},
 			wantErr: true,
-			errMsg:  "engine.WithPgSslmode is only valid for pgsql driver",
+			errMsg:  "WithPgSslmode is only valid for pgsql driver",
 		},
 	}
 
@@ -244,7 +241,7 @@ func TestSQLServerConfig(t *testing.T) {
 				engine.WithSQLiteFile("test.db"),
 			},
 			wantErr: true,
-			errMsg:  "engine.WithSQLiteFile is only valid for sqlite3 driver",
+			errMsg:  "WithSQLiteFile is only valid for sqlite3 driver",
 		},
 	}
 
@@ -285,6 +282,105 @@ func TestInvalidDriver(t *testing.T) {
 	engine.NewDBConfig("oracle")
 }
 
+// TestDuckDBConfig 测试 DuckDB 驱动的配置
+func TestDuckDBConfig(t *testing.T) {
+	tests := []struct {
+		name    string
+		options []engine.Option
+		wantErr bool
+		errMsg  string
+		wantDSN string
+	}{
+		{
+			name: "In-memory database (no file)",
+			options: []engine.Option{},
+			wantErr: false,
+			wantDSN: "",
+		},
+		{
+			name: "File-based database",
+			options: []engine.Option{
+				engine.WithDuckDBFile("test.db"),
+			},
+			wantErr: false,
+			wantDSN: "test.db",
+		},
+		{
+			name: "With access mode",
+			options: []engine.Option{
+				engine.WithDuckDBFile("test.db"),
+				engine.WithDuckDBAccessMode("READ_ONLY"),
+			},
+			wantErr: false,
+			wantDSN: "test.db?access_mode=READ_ONLY",
+		},
+		{
+			name: "With threads",
+			options: []engine.Option{
+				engine.WithDuckDBFile("test.db"),
+				engine.WithDuckDBThreads(4),
+			},
+			wantErr: false,
+			wantDSN: "test.db?threads=4",
+		},
+		{
+			name: "With max memory",
+			options: []engine.Option{
+				engine.WithDuckDBFile("test.db"),
+				engine.WithDuckDBMaxMemory("1GB"),
+			},
+			wantErr: false,
+			wantDSN: "test.db?max_memory=1GB",
+		},
+		{
+			name: "With all options",
+			options: []engine.Option{
+				engine.WithDuckDBFile("test.db"),
+				engine.WithDuckDBAccessMode("READ_WRITE"),
+				engine.WithDuckDBThreads(8),
+				engine.WithDuckDBMaxMemory("2GB"),
+			},
+			wantErr: false,
+		},
+		{
+			name: "With MySQL option (should panic)",
+			options: []engine.Option{
+				engine.WithDuckDBFile("test.db"),
+				engine.WithMySQLCollation("utf8mb4_unicode_ci"),
+			},
+			wantErr: true,
+			errMsg:  "WithMySQLCollation is only valid for mysql driver",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			defer func() {
+				if r := recover(); r != nil {
+					if !tt.wantErr {
+						t.Errorf("engine.NewDBConfig() panicked unexpectedly: %v", r)
+					} else if tt.errMsg != "" && r != tt.errMsg {
+						t.Errorf("engine.NewDBConfig() panic = %v, want %v", r, tt.errMsg)
+					}
+				} else if tt.wantErr {
+					t.Errorf("engine.NewDBConfig() did not panic, expected panic with: %v", tt.errMsg)
+				}
+			}()
+
+			config := engine.NewDBConfig("duckdb", tt.options...)
+			if !tt.wantErr {
+				if config.Driver != "duckdb" {
+					t.Errorf("Driver = %v, want duckdb", config.Driver)
+				}
+				dsn := config.ToDSN()
+				if tt.wantDSN != "" && dsn != tt.wantDSN {
+					t.Errorf("DSN = %v, want %v", dsn, tt.wantDSN)
+				}
+			}
+		})
+	}
+}
+
 // TestDefaultValues 测试默认值
 func TestDefaultValues(t *testing.T) {
 	config := engine.NewDBConfig("mysql",
@@ -358,7 +454,7 @@ func TestToDSN(t *testing.T) {
 				engine.WithPassword("password"),
 				engine.WithSQLServerInstance("SQLEXPRESS"),
 			),
-			wantDSN: "sqlserver://sa:password@sqlserver.example.com\\SQLEXPRESS:1433?server=sqlserver.example.com\\SQLEXPRESS&database=master",
+			wantDSN: "sqlserver://sa:password@sqlserver.example.com\\SQLEXPRESS:1433?database=master&server=sqlserver.example.com%5CSQLEXPRESS",
 			wantErr: false,
 		},
 	}