How Can I Efficiently Left-Pad a VARCHAR in T-SQL?

Optimizing Left-Padding of VARCHARs in T-SQL

Standard T-SQL left-padding techniques often rely on functions like REPLICATE and LEN, resulting in suboptimal performance. A more efficient alternative is:

<code class="language-sql">RIGHT('XXXXXXXXXXXX' + RTRIM(@str), @n)</code>

Here:

• 'X' represents the padding character.
• @n specifies the final padded string length.
• @str is the input string.

This approach efficiently pads @str to the desired length using 'X'. However, it's crucial to minimize database-level padding operations due to potential performance bottlenecks. The best practice is to handle padding within the application layer, thereby enhancing overall SQL query efficiency.

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