What is the Purpose of the 'N' Prefix in T-SQL INSERT Statements, and When Should It Be Used?

In-depth understanding of the meaning and usage of the 'N' prefix in T-SQL statements

In T-SQL INSERT statements, you often see the 'N' prefix, which raises a question: What is its purpose? When should it be used?

The role of the 'N' prefix:

The 'N' prefix indicates that the following string value will be stored in Unicode character type, that is, NCHAR, NVARCHAR or NTEXT. Unicode supports a wider character set, including non-Latin characters, special symbols and emoticons, ensuring accurate representation of data.

When to use the 'N' prefix:

It is crucial to use the 'N' prefix when inserting string values ​​that may contain:

• May contain non-Latin characters or special symbols that are incompatible with the default database code page.
• Needs to preserve precise character representation and prevent character conversion or truncation.
• Stored in a Unicode-enabled database column (e.g., NVARCHAR, NCHAR).

Example:

Consider the following T-SQL INSERT statement:

<code class="language-sql">INSERT INTO Personnel.Employees
VALUES(N'29730', N'Philippe', N'Horsford', 20.05, 1),</code>

The 'N' prefix ensures that the string values ​​of 'Philippe' and 'Horsford' are stored in Unicode characters, retaining their original representation and preventing potential character conversion issues.

Benefits of using the 'N' prefix:

• Enhance data integrity by accurately representing non-Latin characters.
• Prevent data loss due to character conversion or truncation.
• Ensure data consistency by using the universally recognized Unicode character set.

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