值约束SQL Server中非空约束管理必要性（sqlserver 非空）

It goes without saying that protecting data integrity is important for the reliability and security of data stored in databases and, to achieve this, the use of constraints is fundamental. SQL Server allows us to manage the integrity of data using NOT NULL Constraints, which are considered one of the most important ones, as they force us to enter valid values in the columns. To better understand the importance of the management of these constraints, next we will explain some points of view regarding its use.

Adequate management of the NOT NULL Constraints enables the optimization of the search process for values within their columns, since these types of columns do not accept null or empty entries as allowed values. This way, not a single search will be wasted on values that do not exist or are not entered in columns for which the constraint has been established.

In addition, the use of NOT NULL Constraints makes it easier to store valid values that meet the constraints in the database. This helps us to reduce errors associated with data entry, which would eventually lead to errors in data storage.

In the same way, the viability of the data will be high, since it will remain consistent regardless of any modification or operation that is performed. This is accomplished in part through the checking of the information prior to its insertion, which can be done by SQL Server, as shown in the following example.

ALTER TABLE tablename 
    ADD CONSTRAINT non_null_constraintname 
         NOT NULL (columnName);

The NOT NULL Constraints also guarantee the secure insertion of data in columns whenever certain specific parameters such as a certain data type or a format must be followed, which will also result in a decrease in errors due to the automatic discarding of invalid values.

In conclusion, relevant data management is of utmost importance, and the use of the NOT NULL Constraints is the best way to ensure that the parameters required are met, offering a greater guarantee of satisfaction in terms of data reliability and security. We will not only be executing less searches and inserting fewer invalid values, but above all we will be able to count on data that meets the requirements of the specified application or project.