Pastaba.
Prieigai prie šio puslapio reikalingas įgaliojimas. Galite bandyti prisijungti arba pakeisti katalogus.
Prieigai prie šio puslapio reikalingas įgaliojimas. Galite bandyti pakeisti katalogus.
Planning and creating tables requires identifying valid values for the columns and deciding how to enforce the integrity of the data in the columns. SQL Server 2005 provides the following mechanisms to enforce the integrity of the data in a column:
- PRIMARY KEY Constraints
- FOREIGN KEY Constraints
- UNIQUE Constraints
- CHECK Constraints
- DEFAULT Definitions
- Allowing Null Values