fix(sqlserver): recreate primary key when cloning tables

apps/desktop/src/lib/__tests__/database/dbAdminSql.spec.ts

@@ -425,6 +425,44 @@ describe("buildDuplicateTableStructurePlan", () => {
     expect(plan).toEqual({ sql: 'CREATE TABLE "copy" (LIKE "source" INCLUDING ALL);', sourceColumns: undefined, executeAsScript: false });
   });
 
+  it("recreates the SQL Server primary key that SELECT INTO drops", async () => {
+    apiMock.listIndexes.mockResolvedValue([
+      { name: "PK_ORDERS", columns: ["ID", "SEQ"], is_unique: true, is_primary: true },
+      { name: "IDX_ORDERS_CUSTOMER", columns: ["CUSTOMER"], is_unique: false, is_primary: false },
+    ]);
+    apiMock.buildDuplicateTableStructureSql.mockResolvedValue("SELECT TOP 0 * INTO [dbo].[orders_copy] FROM [dbo].[orders];\nALTER TABLE [dbo].[orders_copy] ADD CONSTRAINT [PK_orders_copy] PRIMARY KEY ([ID], [SEQ]);");
+
+    const plan = await buildDuplicateTableStructurePlan({
+      connectionId: "mssql-1",
+      database: "app",
+      databaseType: "sqlserver",
+      schema: "dbo",
+      sourceName: "orders",
+      targetName: "orders_copy",
+    });
+
+    expect(apiMock.listIndexes).toHaveBeenCalledWith("mssql-1", "app", "dbo", "orders", undefined);
+    expect(apiMock.buildDuplicateTableStructureSql).toHaveBeenCalledWith(expect.objectContaining({ databaseType: "sqlserver", primaryKeyColumns: ["ID", "SEQ"] }));
+    expect(plan.executeAsScript).toBe(true);
+  });
+
+  it("keeps primary-key-free SQL Server clones on a single statement", async () => {
+    apiMock.listIndexes.mockResolvedValue([{ name: "IDX_ORDERS_CUSTOMER", columns: ["CUSTOMER"], is_unique: false, is_primary: false }]);
+    apiMock.buildDuplicateTableStructureSql.mockResolvedValue("SELECT TOP 0 * INTO [orders_copy] FROM [orders];");
+
+    const plan = await buildDuplicateTableStructurePlan({
+      connectionId: "mssql-1",
+      database: "app",
+      databaseType: "sqlserver",
+      schema: undefined,
+      sourceName: "orders",
+      targetName: "orders_copy",
+    });
+
+    expect(apiMock.buildDuplicateTableStructureSql).toHaveBeenCalledWith(expect.objectContaining({ databaseType: "sqlserver", primaryKeyColumns: [] }));
+    expect(plan).toEqual({ sql: "SELECT TOP 0 * INTO [orders_copy] FROM [orders];", sourceColumns: undefined, executeAsScript: false });
+  });
+
   it("forwards the connection identifier quote so dual-dialect clones stay executable", async () => {
     // Cloud Spanner's PostgreSQL dialect quotes with double quotes while GoogleSQL uses backticks,
     // and only the connected agent knows which. Dropping the quote here would make the backend fall

apps/desktop/src/lib/database/dbAdminSql.ts

@@ -83,6 +83,9 @@ export interface DuplicateTableStructureSqlOptions {
   targetName: string;
   tableComment?: string | null;
   columnComments?: Array<{ name: string; comment: string }>;
+  /** SQL Server only: source primary-key columns recreated on the clone, because
+   * `SELECT ... INTO` copies columns (and IDENTITY) but drops constraints. */
+  primaryKeyColumns?: string[];
   /** Quote character reported by the connected server, for types whose quote is not fixed by the
    * database type alone (Cloud Spanner's two dialects differ). Mirrors `identifierQuote` on the
    * table-data SQL options. */
@@ -264,6 +267,25 @@ export async function buildDuplicateTableStructurePlan(options: DuplicateTableSt
     return { sql: result.statements.join("\n"), sourceColumns: columns, executeAsScript: true };
   }
 
+  // `SELECT TOP 0 * INTO` copies columns and the IDENTITY property but drops constraints, so the
+  // cloned table silently loses its primary key (t8y2/dbx#8931). Load the source primary key and
+  // let the backend append an `ALTER TABLE ... ADD CONSTRAINT ... PRIMARY KEY` for it.
+  if (options.databaseType === "sqlserver") {
+    const indexes = await api.listIndexes(options.connectionId, options.database, options.schema || "", options.sourceName, options.catalog);
+    const primaryKeyColumns = indexes.find((index) => index.is_primary && index.columns.length > 0)?.columns ?? [];
+    const sql = await buildDuplicateTableStructureSql({
+      databaseType: options.databaseType,
+      schema: options.schema,
+      sourceName: options.sourceName,
+      targetName: options.targetName,
+      tableComment: options.tableComment,
+      columnComments: [],
+      primaryKeyColumns,
+      identifierQuote: options.identifierQuote,
+    });
+    return { sql, sourceColumns: options.sourceColumns, executeAsScript: primaryKeyColumns.length > 0 || duplicateTableStructureRequiresScript(sql) };
+  }
+
   const sql = await buildDuplicateTableStructureSql({
     databaseType: options.databaseType,
     schema: options.schema,