How can I change the field properties in SQL Server?

To modify field properties, you can use the ALTER TABLE statement.

Here is an example of modifying field properties:

ALTER TABLE 表名
ALTER COLUMN 列名 新数据类型;

For example, if you want to change the data type of the column “age” from INT to VARCHAR(50), you can use the following statement:

ALTER TABLE 表名
ALTER COLUMN age VARCHAR(50);

You can also modify other properties in the ALTER TABLE statement, such as adding constraints, changing default values, etc.

Please be aware that modifying field properties in certain cases may result in data loss or changing data types may not allow for data conversion. Before changing field properties, make sure to backup data or perform appropriate testing.