what
ac81f1ff0b
- 新增 dialect/sqlite3/vtab 包，提供干净的虚拟表接口（Module/Table/Cursor） - 适配层自动将 BestIndex 约束与 Filter 值绑定（ConstraintInfo.Value），无需手动编解码 IdxStr - 支持 OpLIMIT/OpOFFSET 约束下推 - 新增 SupportsDistinct 方言选项，控制 SELECT 级和表达式级 DISTINCT 生成 - sqlite3 方言注册 IF() 函数支持
366 lines
8.4 KiB
Go
366 lines
8.4 KiB
Go
//go:build sqlite_vtable || vtable
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package vtab_test
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import (
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"database/sql"
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"testing"
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"git.fsdpf.net/go/db/dialect/sqlite3/vtab"
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"github.com/stretchr/testify/suite"
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)
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// ─── 内存表实现（用于测试）───────────────────────────────────
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//
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// 模拟一张 users 表，数据存在内存 slice 中，支持完整 CRUD。
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type userRow struct {
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id int64
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name string
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age int64
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}
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// usersModule 是虚拟表工厂
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type usersModule struct{}
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func (m *usersModule) Create(args []string, declare func(string) error) (vtab.Table, error) {
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if err := declare("CREATE TABLE users(id INTEGER, name TEXT, age INTEGER)"); err != nil {
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return nil, err
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}
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return newUsersTable(), nil
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}
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func (m *usersModule) Connect(args []string, declare func(string) error) (vtab.Table, error) {
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return m.Create(args, declare)
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}
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// usersTable 是虚拟表实例，同时实现 WritableTable
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type usersTable struct {
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rows []userRow
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nextID int64
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}
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func newUsersTable() *usersTable {
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return &usersTable{
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nextID: 1,
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rows: []userRow{
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{1, "Alice", 30},
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{2, "Bob", 25},
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{3, "Charlie", 35},
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},
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}
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}
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// BestIndex：不做任何约束下推，由 SQLite 全表扫描后过滤
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func (t *usersTable) BestIndex(constraints []vtab.ConstraintInfo, _ []vtab.OrderByInfo) (*vtab.IndexOutput, error) {
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return &vtab.IndexOutput{
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Used: make([]bool, len(constraints)), // 全部 false
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EstimatedCost: float64(len(t.rows)),
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EstimatedRows: float64(len(t.rows)),
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}, nil
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}
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func (t *usersTable) Open() (vtab.Cursor, error) {
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return &usersCursor{rows: t.rows}, nil
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}
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func (t *usersTable) Disconnect() error { return nil }
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func (t *usersTable) Destroy() error { return nil }
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// ── WritableTable ──
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func (t *usersTable) Insert(values []any) (int64, error) {
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// values: [id, name, age]，id 可能为 nil（自动生成）
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id := t.nextID
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t.nextID++
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if values[0] != nil {
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id = toInt64(values[0])
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}
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name, _ := values[1].(string)
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age := toInt64(values[2])
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t.rows = append(t.rows, userRow{id, name, age})
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return id, nil
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}
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func (t *usersTable) Update(rowid any, values []any) error {
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rid := toInt64(rowid)
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for i, r := range t.rows {
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if r.id == rid {
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if values[1] != nil {
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t.rows[i].name, _ = values[1].(string)
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}
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if values[2] != nil {
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t.rows[i].age = toInt64(values[2])
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}
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return nil
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}
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}
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return nil
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}
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func (t *usersTable) Delete(rowid any) error {
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rid := toInt64(rowid)
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for i, r := range t.rows {
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if r.id == rid {
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t.rows = append(t.rows[:i], t.rows[i+1:]...)
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return nil
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}
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}
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return nil
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}
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// ── Cursor ──
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type usersCursor struct {
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rows []userRow
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pos int
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}
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func (c *usersCursor) Filter(_ int, _ []vtab.ConstraintInfo) error {
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c.pos = 0
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return nil
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}
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func (c *usersCursor) Next() error { c.pos++; return nil }
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func (c *usersCursor) EOF() bool { return c.pos >= len(c.rows) }
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func (c *usersCursor) Close() error { return nil }
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func (c *usersCursor) Rowid() (int64, error) {
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return c.rows[c.pos].id, nil
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}
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func (c *usersCursor) Column(col int) (any, error) {
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r := c.rows[c.pos]
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switch col {
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case 0:
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return r.id, nil
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case 1:
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return r.name, nil
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case 2:
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return r.age, nil
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}
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return nil, nil
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}
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func toInt64(v any) int64 {
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switch x := v.(type) {
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case int64:
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return x
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case int:
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return int64(x)
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case float64:
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return int64(x)
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}
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return 0
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}
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// ─── 测试套件 ─────────────────────────────────────────────────
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func init() {
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vtab.Register("users_mod", &usersModule{})
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}
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type VtabSuite struct {
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suite.Suite
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db *sql.DB
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}
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func (s *VtabSuite) SetupSuite() {
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db, err := sql.Open(vtab.DriverName, ":memory:")
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s.Require().NoError(err)
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s.db = db
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}
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func (s *VtabSuite) TearDownSuite() {
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s.db.Close()
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}
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// SetupTest 每个测试前重建虚拟表，保证初始数据一致
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func (s *VtabSuite) SetupTest() {
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s.db.Exec(`DROP TABLE IF EXISTS users`)
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_, err := s.db.Exec(`CREATE VIRTUAL TABLE users USING users_mod()`)
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s.Require().NoError(err)
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}
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// ── SELECT ──
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func (s *VtabSuite) TestSelect_All() {
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rows, err := s.db.Query(`SELECT id, name, age FROM users ORDER BY id`)
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s.Require().NoError(err)
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defer rows.Close()
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var result []userRow
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for rows.Next() {
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var r userRow
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s.Require().NoError(rows.Scan(&r.id, &r.name, &r.age))
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result = append(result, r)
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}
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s.Require().NoError(rows.Err())
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s.Equal([]userRow{
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{1, "Alice", 30},
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{2, "Bob", 25},
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{3, "Charlie", 35},
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}, result)
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}
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func (s *VtabSuite) TestSelect_Where() {
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rows, err := s.db.Query(`SELECT name FROM users WHERE age > 28 ORDER BY id`)
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s.Require().NoError(err)
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defer rows.Close()
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var names []string
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for rows.Next() {
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var name string
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s.Require().NoError(rows.Scan(&name))
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names = append(names, name)
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}
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s.Equal([]string{"Alice", "Charlie"}, names)
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}
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func (s *VtabSuite) TestSelect_IF() {
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var label string
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err := s.db.QueryRow(`SELECT IF(age >= 30, 'senior', 'junior') FROM users WHERE id = 2`).Scan(&label)
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s.Require().NoError(err)
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s.Equal("junior", label)
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}
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// ── INSERT ──
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func (s *VtabSuite) TestInsert() {
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_, err := s.db.Exec(`INSERT INTO users(name, age) VALUES(?, ?)`, "Dave", 28)
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s.Require().NoError(err)
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var count int
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s.Require().NoError(s.db.QueryRow(`SELECT COUNT(*) FROM users WHERE name = 'Dave'`).Scan(&count))
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s.Equal(1, count)
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}
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// ── UPDATE ──
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func (s *VtabSuite) TestUpdate() {
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_, err := s.db.Exec(`UPDATE users SET age = ? WHERE name = ?`, 26, "Bob")
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s.Require().NoError(err)
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var age int64
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s.Require().NoError(s.db.QueryRow(`SELECT age FROM users WHERE name = 'Bob'`).Scan(&age))
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s.Equal(int64(26), age)
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}
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// ── DELETE ──
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func (s *VtabSuite) TestDelete() {
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_, err := s.db.Exec(`DELETE FROM users WHERE name = ?`, "Charlie")
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s.Require().NoError(err)
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var count int
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s.Require().NoError(s.db.QueryRow(`SELECT COUNT(*) FROM users WHERE name = 'Charlie'`).Scan(&count))
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s.Equal(0, count)
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}
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// ── JOIN with real table ──
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// TestJoin_VtabAndRealTable 演示虚拟表与真实表的 JOIN。
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//
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// 真实表 orders：每条订单记录 user_id 和 amount。
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// 虚拟表 users：内存中的用户数据。
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// 查询：统计每个用户的订单总金额，只返回有订单的用户。
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func (s *VtabSuite) TestJoin_VtabAndRealTable() {
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// 建真实表并插入数据
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_, err := s.db.Exec(`
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CREATE TABLE IF NOT EXISTS orders (
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id INTEGER PRIMARY KEY AUTOINCREMENT,
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user_id INTEGER NOT NULL,
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amount REAL NOT NULL
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)`)
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s.Require().NoError(err)
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defer s.db.Exec(`DROP TABLE IF EXISTS orders`)
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_, err = s.db.Exec(`
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INSERT INTO orders(user_id, amount) VALUES
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(1, 100.0),
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(1, 50.5),
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(2, 200.0),
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(3, 75.0),
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(3, 25.0)`)
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s.Require().NoError(err)
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// vtab users INNER JOIN real orders
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rows, err := s.db.Query(`
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SELECT u.name, SUM(o.amount) AS total
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FROM users AS u
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JOIN orders AS o ON o.user_id = u.id
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GROUP BY u.id, u.name
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ORDER BY u.id`)
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s.Require().NoError(err)
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defer rows.Close()
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type row struct {
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name string
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total float64
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}
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var result []row
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for rows.Next() {
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var r row
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s.Require().NoError(rows.Scan(&r.name, &r.total))
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result = append(result, r)
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}
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s.Require().NoError(rows.Err())
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s.Equal([]row{
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{"Alice", 150.5},
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{"Bob", 200.0},
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{"Charlie", 100.0},
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}, result)
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}
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// TestJoin_VtabLeftJoinRealTable 演示 LEFT JOIN：列出所有用户及其订单数，没有订单的用户显示 0。
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func (s *VtabSuite) TestJoin_VtabLeftJoinRealTable() {
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_, err := s.db.Exec(`
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CREATE TABLE IF NOT EXISTS orders (
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id INTEGER PRIMARY KEY AUTOINCREMENT,
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user_id INTEGER NOT NULL,
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amount REAL NOT NULL
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)`)
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s.Require().NoError(err)
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defer s.db.Exec(`DROP TABLE IF EXISTS orders`)
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// 只给 Alice 和 Bob 插入订单，Charlie 没有订单
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_, err = s.db.Exec(`
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INSERT INTO orders(user_id, amount) VALUES
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(1, 100.0),
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(2, 200.0)`)
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s.Require().NoError(err)
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rows, err := s.db.Query(`
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SELECT u.name, COUNT(o.id) AS order_count
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FROM users AS u
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LEFT JOIN orders AS o ON o.user_id = u.id
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GROUP BY u.id, u.name
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ORDER BY u.id`)
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s.Require().NoError(err)
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defer rows.Close()
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type row struct {
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name string
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count int
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}
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var result []row
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for rows.Next() {
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var r row
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s.Require().NoError(rows.Scan(&r.name, &r.count))
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result = append(result, r)
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}
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s.Require().NoError(rows.Err())
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s.Equal([]row{
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{"Alice", 1},
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{"Bob", 1},
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{"Charlie", 0}, // 没有订单，LEFT JOIN 保留
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}, result)
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}
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func TestVtabSuite(t *testing.T) {
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suite.Run(t, new(VtabSuite))
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}
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