diff --git a/api/alembic/versions/5bb5281de909_make_workspace_id_required.py b/api/alembic/versions/5bb5281de909_make_workspace_id_required.py
new file mode 100644
index 0000000..70877e0
--- /dev/null
+++ b/api/alembic/versions/5bb5281de909_make_workspace_id_required.py
@@ -0,0 +1,113 @@
+"""Make_workspace_id_required_and_update_foreign_key_constraints
+
+Revision ID: 5bb5281de909
+Revises: 54ffc5a9b833
+Create Date: 2026-01-31 11:20:54.887765
+
+"""
+
+from typing import Sequence, Union
+
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision: str = "5bb5281de909"
+down_revision: Union[str, Sequence[str], None] = "54ffc5a9b833"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    """Upgrade schema."""
+    # ### commands auto generated by Alembic - please adjust! ###
+
+    # 将 files 表的 workspace_id 设置为必填字段
+    op.alter_column(
+        "files", "workspace_id", existing_type=sa.VARCHAR(length=36), nullable=False
+    )
+
+    # 将 folders 表的 workspace_id 设置为必填字段
+    op.alter_column(
+        "folders", "workspace_id", existing_type=sa.VARCHAR(length=36), nullable=False
+    )
+
+    # 将 notes 表的 workspace_id 设置为必填字段
+    op.alter_column(
+        "notes", "workspace_id", existing_type=sa.VARCHAR(length=36), nullable=False
+    )
+
+    # 将 storage_backends 表的 workspace_id 设置为必填字段
+    op.alter_column(
+        "storage_backends",
+        "workspace_id",
+        existing_type=sa.VARCHAR(length=36),
+        nullable=False,
+    )
+
+    # 将 workspace_user_association 表的 created_at 改为可选字段
+    op.alter_column(
+        "workspace_user_association",
+        "created_at",
+        existing_type=postgresql.TIMESTAMP(),
+        nullable=True,
+    )
+
+    # 删除旧的工作空间外键约束（带有 SET NULL 行为）
+    op.drop_constraint(
+        op.f("workspaces_created_by_fkey"), "workspaces", type_="foreignkey"
+    )
+
+    # 创建新的工作空间外键约束（使用默认删除行为）
+    op.create_foreign_key(None, "workspaces", "users", ["created_by"], ["id"])
+    # ### end Alembic commands ###
+
+
+def downgrade() -> None:
+    """Downgrade schema."""
+    # ### commands auto generated by Alembic - please adjust! ###
+
+    # 恢复外键约束为原来的 SET NULL 行为
+    op.drop_constraint(None, "workspaces", type_="foreignkey")
+    op.create_foreign_key(
+        op.f("workspaces_created_by_fkey"),
+        "workspaces",
+        "users",
+        ["created_by"],
+        ["id"],
+        ondelete="SET NULL",
+    )
+
+    # 恢复 workspace_user_association 表的 created_at 为必填字段
+    op.alter_column(
+        "workspace_user_association",
+        "created_at",
+        existing_type=postgresql.TIMESTAMP(),
+        nullable=False,
+    )
+
+    # 恢复 storage_backends 表的 workspace_id 为可选字段
+    op.alter_column(
+        "storage_backends",
+        "workspace_id",
+        existing_type=sa.VARCHAR(length=36),
+        nullable=True,
+    )
+
+    # 恢复 notes 表的 workspace_id 为可选字段
+    op.alter_column(
+        "notes", "workspace_id", existing_type=sa.VARCHAR(length=36), nullable=True
+    )
+
+    # 恢复 folders 表的 workspace_id 为可选字段
+    op.alter_column(
+        "folders", "workspace_id", existing_type=sa.VARCHAR(length=36), nullable=True
+    )
+
+    # 恢复 files 表的 workspace_id 为可选字段
+    op.alter_column(
+        "files", "workspace_id", existing_type=sa.VARCHAR(length=36), nullable=True
+    )
+    # ### end Alembic commands ###