我处理过很多类似的schema对比需求，针对你要找 旧数据库有但新数据库缺失的列 这个核心诉求，下面几个方法亲测好用：

1. 用系统视图编写自定义查询（最灵活，无需额外工具） #

直接利用SQL Server的系统视图跨库查询，精准筛选差异。把下面脚本里的 OldDatabaseName 和 NewDatabaseName 替换成你的实际库名即可：

SELECT
    t1.table_schema AS 表架构,
    t1.table_name AS 表名,
    c1.column_name AS 缺失的列名,
    c1.data_type AS 列数据类型,
    c1.is_nullable AS 是否允许为空
    OldDatabaseName.INFORMATION_SCHEMA.COLUMNS c1
    OldDatabaseName.INFORMATION_SCHEMA.TABLES t1 ON c1.table_schema = t1.table_schema AND c1.table_name = t1.table_name
LEFT JOIN
    NewDatabaseName.INFORMATION_SCHEMA.COLUMNS c2 ON c1.table_schema = c2.table_schema 
                                                AND c1.table_name = c2.table_name 
                                                AND c1.column_name = c2.column_name
WHERE