🐛 fix(sql): 适配多数据源 SQL 方言生成

- 表设计 DDL 按 Oracle/Dameng、SQL Server、PG-family、SQLite/DuckDB、ClickHouse/TDengine 分支生成

- 新增统一 SQL 方言工具，驱动字段类型候选和 SQL 自动补全

- 修复 Oracle/Dameng DATE/TIMESTAMP 删除条件字面量

- 补充多方言 DDL、补全和 Oracle 删除回归测试

Refs #402

Refs #409

frontend/src/components/tableDesignerSchemaSql.test.ts

@@ -1,6 +1,7 @@
 import { describe, expect, it } from 'vitest';
 
 import {
+  buildCreateTablePreviewSql,
   buildAlterTablePreviewSql,
   hasAlterTableDraftChanges,
   type BuildAlterTablePreviewInput,
@@ -76,4 +77,140 @@ describe('tableDesignerSchemaSql', () => {
     expect(sql).toContain('FIRST');
     expect(sql).not.toContain('MODIFY COLUMN `display_name`');
   });
+
+  it('builds oracle alter preview with oracle rename and modify syntax', () => {
+    const sql = buildAlterTablePreviewSql(buildInput({
+      dbType: 'oracle',
+      tableName: 'HR.EMPLOYEES',
+      originalColumns: [
+        baseColumn({ _key: 'name', name: 'NAME', type: 'VARCHAR2(64)', nullable: 'YES', comment: '旧名称' }),
+      ],
+      columns: [
+        baseColumn({
+          _key: 'name',
+          name: 'DISPLAY_NAME',
+          type: 'VARCHAR2(128)',
+          nullable: 'NO',
+          default: 'guest',
+          comment: '显示名',
+        }),
+      ],
+    }));
+
+    expect(sql).toContain('ALTER TABLE "HR"."EMPLOYEES"\nRENAME COLUMN "NAME" TO "DISPLAY_NAME";');
+    expect(sql).toContain(`ALTER TABLE "HR"."EMPLOYEES"\nMODIFY ("DISPLAY_NAME" VARCHAR2(128) DEFAULT 'guest' NOT NULL);`);
+    expect(sql).toContain(`COMMENT ON COLUMN "HR"."EMPLOYEES"."DISPLAY_NAME" IS '显示名';`);
+    expect(sql).not.toContain('`');
+    expect(sql).not.toContain('CHANGE COLUMN');
+    expect(sql).not.toContain('AUTO_INCREMENT');
+  });
+
+  it('builds sqlserver alter preview with sp_rename and alter column syntax', () => {
+    const sql = buildAlterTablePreviewSql(buildInput({
+      dbType: 'sqlserver',
+      tableName: 'dbo.Users',
+      originalColumns: [
+        baseColumn({ _key: 'name', name: 'name', type: 'nvarchar(64)', nullable: 'YES' }),
+      ],
+      columns: [
+        baseColumn({ _key: 'name', name: 'display_name', type: 'nvarchar(128)', nullable: 'NO' }),
+      ],
+    }));
+
+    expect(sql).toContain(`EXEC sp_rename 'dbo.Users.name', 'display_name', 'COLUMN';`);
+    expect(sql).toContain('ALTER TABLE [dbo].[Users]\nALTER COLUMN [display_name] nvarchar(128) NOT NULL;');
+    expect(sql).not.toContain('CHANGE COLUMN');
+    expect(sql).not.toContain('MODIFY COLUMN');
+    expect(sql).not.toContain('`');
+  });
+
+  it('keeps sqlite alter preview limited to sqlite-supported operations', () => {
+    const sql = buildAlterTablePreviewSql(buildInput({
+      dbType: 'sqlite',
+      tableName: 'users',
+      originalColumns: [
+        baseColumn({ _key: 'name', name: 'name', type: 'TEXT', nullable: 'YES' }),
+      ],
+      columns: [
+        baseColumn({ _key: 'name', name: 'display_name', type: 'INTEGER', nullable: 'NO' }),
+      ],
+    }));
+
+    expect(sql).toContain('ALTER TABLE "users"\nRENAME COLUMN "name" TO "display_name";');
+    expect(sql).toContain('-- SQLite 不支持直接修改字段属性');
+    expect(sql).not.toContain('CHANGE COLUMN');
+    expect(sql).not.toContain('MODIFY COLUMN');
+    expect(sql).not.toContain('AFTER');
+  });
+
+  it('builds duckdb alter preview without mysql-only syntax', () => {
+    const sql = buildAlterTablePreviewSql(buildInput({
+      dbType: 'duckdb',
+      tableName: 'main.users',
+      originalColumns: [
+        baseColumn({ _key: 'score', name: 'score', type: 'INTEGER', nullable: 'YES', default: '0' }),
+      ],
+      columns: [
+        baseColumn({ _key: 'score', name: 'score', type: 'BIGINT', nullable: 'NO', default: '1' }),
+      ],
+    }));
+
+    expect(sql).toContain('ALTER TABLE "main"."users"\nALTER COLUMN "score" SET DATA TYPE BIGINT;');
+    expect(sql).toContain('ALTER TABLE "main"."users"\nALTER COLUMN "score" SET DEFAULT 1;');
+    expect(sql).toContain('ALTER TABLE "main"."users"\nALTER COLUMN "score" SET NOT NULL;');
+    expect(sql).not.toContain('CHANGE COLUMN');
+    expect(sql).not.toContain('MODIFY COLUMN');
+  });
+
+  it('uses native limited alter syntax for clickhouse and tdengine instead of mysql syntax', () => {
+    const clickhouseSql = buildAlterTablePreviewSql(buildInput({
+      dbType: 'clickhouse',
+      tableName: 'events',
+      originalColumns: [baseColumn({ _key: 'name', name: 'name', type: 'String', nullable: 'YES' })],
+      columns: [baseColumn({ _key: 'name', name: 'display_name', type: 'String', nullable: 'YES' })],
+    }));
+    const tdengineSql = buildAlterTablePreviewSql(buildInput({
+      dbType: 'tdengine',
+      tableName: 'meters',
+      originalColumns: [baseColumn({ _key: 'value', name: 'value', type: 'FLOAT', nullable: 'YES' })],
+      columns: [baseColumn({ _key: 'value', name: 'value', type: 'DOUBLE', nullable: 'YES' })],
+    }));
+
+    expect(clickhouseSql).toContain('ALTER TABLE `events`\nRENAME COLUMN `name` TO `display_name`;');
+    expect(tdengineSql).toContain('ALTER TABLE `meters`\nMODIFY COLUMN `value` DOUBLE;');
+    expect(clickhouseSql).not.toContain('CHANGE COLUMN');
+    expect(tdengineSql).not.toContain('CHANGE COLUMN');
+    expect(clickhouseSql).not.toContain('AFTER');
+    expect(tdengineSql).not.toContain('AFTER');
+  });
+
+  it('treats mariadb doris and sphinx as mysql-family only where mysql syntax is intended', () => {
+    for (const dbType of ['mariadb', 'diros', 'sphinx']) {
+      const sql = buildAlterTablePreviewSql(buildInput({ dbType }));
+      expect(sql).toContain('ALTER TABLE `users`');
+      expect(sql).toContain('ADD COLUMN `age` int NULL');
+    }
+  });
+
+  it('builds oracle create table preview without mysql table options', () => {
+    const sql = buildCreateTablePreviewSql({
+      dbType: 'oracle',
+      tableName: 'HR.EMPLOYEES',
+      charset: 'utf8mb4',
+      collation: 'utf8mb4_unicode_ci',
+      columns: [
+        baseColumn({ _key: 'id', name: 'ID', type: 'NUMBER(10)', nullable: 'NO', key: 'PRI', isAutoIncrement: true }),
+        baseColumn({ _key: 'name', name: 'NAME', type: 'VARCHAR2(255)', nullable: 'YES', comment: '姓名' }),
+      ],
+    });
+
+    expect(sql).toContain('CREATE TABLE "HR"."EMPLOYEES"');
+    expect(sql).toContain('"ID" NUMBER(10) GENERATED BY DEFAULT AS IDENTITY NOT NULL');
+    expect(sql).toContain('PRIMARY KEY ("ID")');
+    expect(sql).toContain(`COMMENT ON COLUMN "HR"."EMPLOYEES"."NAME" IS '姓名';`);
+    expect(sql).not.toContain('ENGINE=InnoDB');
+    expect(sql).not.toContain('DEFAULT CHARSET');
+    expect(sql).not.toContain('AUTO_INCREMENT');
+    expect(sql).not.toContain('`');
+  });
 });