ssms的alter table
时间: 2023-12-12 11:35:55 浏览: 31
`SSMS`中的`ALTER TABLE`用于修改已有表的结构。以下是一些常见的用法:
1. 添加列
```sql
ALTER TABLE table_name ADD column_name datatype
```
2. 修改列
```sqlALTER TABLE table_name ALTER COLUMN column_name datatype
```
3. 删除列
```sql
ALTER TABLE table_name DROP COLUMN column_name
```
4. 添加主键
```sql
ALTER TABLE table_name ADD CONSTRAINT constraint_name PRIMARY KEY (column_name)
```
5. 添加外键
```sql
ALTER TABLE table_name ADD CONSTRAINT constraint_name FOREIGN KEY (column_name) REFERENCES other_table_name (other_column_name)
```
6. 删除外键
```sql
ALTER TABLE table_name DROP CONSTRAINT constraint_name
```
7. 修改表名
```sql
EXEC sp_rename 'old_table_name', 'new_table_name'
```
8. 修改列名
```sql
EXEC sp_rename 'table_name.old_column_name', 'new_column_name', 'COLUMN'
```