TsDB2/DB/query_select_test.go

package DB

import (
	"path/filepath"
	"testing"
)

// TestQuerySelectProjection ORM 层 Select 投影: 只解码选中列,
// 未选中字段保持零值; 与 ORDER BY 组合时排序仍正确。
func TestQuerySelectProjection(t *testing.T) {
	type Emp struct {
		BaseModel
		Name  string `vrtx:"maxlen:32"`
		Age   int64  `vrtx:"index"`
		Score int64
	}

	db, err := Open(filepath.Join(t.TempDir(), "test.db"))
	if err != nil {
		t.Fatalf("open: %v", err)
	}
	defer db.Close()

	tbl, err := UseTable[Emp](db, "emp")
	if err != nil {
		t.Fatalf("use table: %v", err)
	}
	for i := 1; i <= 20; i++ {
		if err := tbl.Insert(&Emp{Name: "n", Age: int64(i), Score: int64(i * 10)}); err != nil {
			t.Fatalf("insert %d: %v", i, err)
		}
	}
	if err := db.Commit(); err != nil {
		t.Fatalf("commit: %v", err)
	}

	// 只选 Age: Name/Score 为零值, Age 正确
	rows, err := tbl.Query().Select("Age").Where("Age", ">", int64(17)).OrderBy("Age").Find()
	if err != nil {
		t.Fatalf("select: %v", err)
	}
	if len(rows) != 3 {
		t.Fatalf("应命中 3 行, 得到 %d", len(rows))
	}
	for i, r := range rows {
		want := int64(18 + i)
		if r.Age != want || r.Name != "" || r.Score != 0 {
			t.Fatalf("第 %d 行 = %+v, 想要 Age=%d 其余零值", i, r, want)
		}
	}

	// 全列对照: 不限 select 时所有字段都在
	full, err := tbl.Query().Where("Age", "=", int64(5)).Find()
	if err != nil {
		t.Fatalf("full: %v", err)
	}
	if len(full) != 1 || full[0].Name != "n" || full[0].Score != 50 {
		t.Fatalf("全列查询结果 %+v", full[0])
	}
}