SQL Server and Access database structure SQL statements

The following are common SQL statements used by SQL Server and Access to operate database structures.
The content is organized by Hai Wa. If the content is incorrect or incomplete, please submit it. Thank you.
Create a table:
Create table [table name]
(
[Automatic number field] int IDENTITY (1, 1) primary key,
[Field 1] nVarChar (50) default 'default value 'null,
[Field 2] ntext null,
[Field 3] datetime,
[Field 4] money null,
[Field 5] int default 0,
[Field 6] Decimal (12, 4) default 0,
[Field 7] image null,
)
Delete table:
Drop table [table name]
Insert data:
Insert into [table name] (Field 1, field 2) VALUES (100, '51windows. Net ')
Delete data:
Delete from [table name] WHERE [field name]> 100
Update data:
UPDATE [table name] SET [Field 1] = 200, [field 2] = '51windows. Net' WHERE [field 3] = 'haiwa'
New field:
Alter table [TABLE name] ADD [field name] NVARCHAR (50) NULL
Delete field:
Alter table [TABLE name] drop column [field name]
Modify field:
Alter table [TABLE name] alter column [field name] NVARCHAR (50) NULL
Rename a table: (Access to rename a table, refer to the article: rename a table in Access database)
Sp_rename 'table name', 'New table name', 'object'
New constraint:
Alter table [TABLE name] add constraint name CHECK ([CONSTRAINT field] <= '2017-1-1 ')
Delete constraints:
Alter table [TABLE name] drop constraint name
Create default value
Alter table [TABLE name] add constraint default name: '51windows. Net' FOR [field name]
Delete default value
Alter table [TABLE name] drop constraint default name