SQL server database system organization-create and manage data tables

Source: Internet
Author: User

Note:

1. The fixed-length character type occupies more space than the non-fixed-length character type, but the fixed-length character type does not need to be processed during field value setting, therefore, the processing speed is faster. Therefore, for data with a relatively fixed length, using a fixed length character type will increase the system's performance.

2. modify an existing data TABLE and ADD field Syntax: alter table name to be modified ADD field Name field type

3. modify an existing data TABLE and delete the field Syntax: alter table: the name of the TABLE to be modified DROP the name of the field to be deleted

4. syntax for deleting a data TABLE: drop table name to be deleted


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