{
    "summary": [
        {
            "name": "contract_versions",
            "title": "合同版本管理表",
            "primary": "id",
            "catelog": "relation"
        }
    ],
    "fields": [
        {
            "name": "id",
            "title": "版本ID",
            "type": "str",
            "length": 32,
            "nullable": "no",
            "comments": "主键 - UUID格式"
        },
        {
            "name": "contract_id",
            "title": "合同ID",
            "type": "str",
            "length": 32,
            "nullable": "no",
            "comments": "关联的合同ID"
        },
        {
            "name": "version_number",
            "title": "版本号",
            "type": "str",
            "length": 20,
            "nullable": "no",
            "comments": "版本号，如v1.0, v1.1等"
        },
        {
            "name": "content",
            "title": "合同内容",
            "type": "text",
            "nullable": "no",
            "comments": "合同完整内容或差异内容"
        },
        {
            "name": "diff_content",
            "title": "差异内容",
            "type": "text",
            "nullable": "yes",
            "comments": "与上一版本的差异内容（HTML格式）"
        },
        {
            "name": "modified_by",
            "title": "修改人ID",
            "type": "str",
            "length": 32,
            "nullable": "no",
            "comments": "修改人用户ID"
        },
        {
            "name": "modified_reason",
            "title": "修改原因",
            "type": "text",
            "nullable": "yes",
            "comments": "版本修改原因"
        },
        {
            "name": "created_at",
            "title": "创建时间",
            "type": "timestamp",
            "nullable": "no",
            "comments": "版本创建时间"
        },
        {
            "name": "is_current",
            "title": "是否当前版本",
            "type": "str",
            "length": 1,
            "nullable": "no",
            "default": "0",
            "comments": "是否为当前生效版本：1=是, 0=否"
        }
    ],
    "indexes": [
        {
            "name": "idx_contract_versions_contract",
            "idxtype": "index",
            "idxfields": ["contract_id"]
        },
        {
            "name": "idx_contract_versions_version",
            "idxtype": "unique",
            "idxfields": ["contract_id", "version_number"]
        },
        {
            "name": "idx_contract_versions_current",
            "idxtype": "index",
            "idxfields": ["contract_id", "is_current"]
        }
    ]
}