feat: metona-sqlark v0.1.12 — 前端TypeScript关系型数据库

- 4种存储引擎：Memory / IndexedDB / OPFS / Hybrid
- 完整SQL支持：SELECT/INSERT/UPDATE/DELETE/JOIN/GROUP BY/HAVING/DISTINCT
- Query Builder链式API + TypeScript泛型支持
- 聚合函数：COUNT/SUM/AVG/MIN/MAX
- 事务、插件系统(14 hooks)、发布订阅、数据迁移、导入导出
- React/Vue框架集成
- 264个测试用例，93.46%覆盖率
- 零运行时依赖

src/query/ast.ts

@@ -0,0 +1,157 @@
+/**
+ * metona-sqlark Query AST — 查询抽象语法树类型定义
+ * @module query/ast
+ *
+ * QueryBuilder 和 SQL Parser 统一输出此 AST，
+ * Executor 只认 AST，保证两种查询接口行为一致。
+ */
+
+import type { WhereCondition, OrderBy } from '../constants';
+
+// ---------------------------------------------------------------------------
+//  AST 语句类型枚举
+// ---------------------------------------------------------------------------
+
+export type StatementType =
+  | 'SELECT'
+  | 'INSERT'
+  | 'UPDATE'
+  | 'DELETE'
+  | 'CREATE_TABLE'
+  | 'DROP_TABLE';
+
+// ---------------------------------------------------------------------------
+//  列引用
+// ---------------------------------------------------------------------------
+
+/** 列引用，'*' 表示所有列；支持 'table.column' 格式 */
+export type ColumnRef = string;
+
+// ---------------------------------------------------------------------------
+//  JOIN
+// ---------------------------------------------------------------------------
+
+/** JOIN 类型 */
+export type JoinType = 'INNER' | 'LEFT' | 'RIGHT' | 'CROSS';
+
+/** JOIN 子句 */
+export interface JoinClause {
+  type: JoinType;
+  table: string;
+  alias?: string;
+  on: WhereCondition;
+}
+
+// ---------------------------------------------------------------------------
+//  聚合函数
+// ---------------------------------------------------------------------------
+
+/** 聚合函数类型 */
+export type AggregateFunc = 'COUNT' | 'SUM' | 'AVG' | 'MIN' | 'MAX';
+
+/** 聚合表达式 */
+export interface AggregateExpression {
+  type: 'AGGREGATE';
+  func: AggregateFunc;
+  column: string; // '*' for COUNT(*)
+  alias?: string;
+}
+
+// ---------------------------------------------------------------------------
+//  DDL: CREATE TABLE
+// ---------------------------------------------------------------------------
+
+export interface ASTColumnDef {
+  name: string;
+  type: string;
+  primaryKey?: boolean;
+  unique?: boolean;
+  required?: boolean;
+  default?: unknown;
+  index?: boolean;
+  maxLength?: number;
+  min?: number;
+  max?: number;
+}
+
+export interface CreateTableStatement {
+  type: 'CREATE_TABLE';
+  name: string;
+  columns: ASTColumnDef[];
+}
+
+// ---------------------------------------------------------------------------
+//  DDL: DROP TABLE
+// ---------------------------------------------------------------------------
+
+export interface DropTableStatement {
+  type: 'DROP_TABLE';
+  name: string;
+}
+
+// ---------------------------------------------------------------------------
+//  DML: INSERT
+// ---------------------------------------------------------------------------
+
+export interface InsertStatement {
+  type: 'INSERT';
+  into: string;
+  columns?: string[];
+  values: unknown[][];
+}
+
+// ---------------------------------------------------------------------------
+//  DML: UPDATE
+// ---------------------------------------------------------------------------
+
+export interface UpdateStatement {
+  type: 'UPDATE';
+  table: string;
+  sets: Record<string, unknown>;
+  where: WhereCondition;
+}
+
+// ---------------------------------------------------------------------------
+//  DML: DELETE
+// ---------------------------------------------------------------------------
+
+export interface DeleteStatement {
+  type: 'DELETE';
+  from: string;
+  where: WhereCondition;
+}
+
+// ---------------------------------------------------------------------------
+//  DQL: SELECT
+// ---------------------------------------------------------------------------
+
+export interface SelectStatement {
+  type: 'SELECT';
+  columns: ColumnRef[];
+  distinct?: boolean;
+  from: string;
+  /** 主表别名 */
+  alias?: string;
+  /** JOIN 子句列表 */
+  joins?: JoinClause[];
+  where: WhereCondition;
+  /** GROUP BY */
+  groupBy?: string[];
+  /** HAVING */
+  having?: WhereCondition;
+  orderBy?: OrderBy[];
+  limit?: number;
+  offset?: number;
+}
+
+// ---------------------------------------------------------------------------
+//  AST 联合类型
+// ---------------------------------------------------------------------------
+
+export type Statement =
+  | SelectStatement
+  | InsertStatement
+  | UpdateStatement
+  | DeleteStatement
+  | CreateTableStatement
+  | DropTableStatement;