Converting Varchar(10) to Integer in MS SQL without Schema Change скачать в хорошем качестве

Converting Varchar(10) to Integer in MS SQL without Schema Change

Learn how to efficiently convert a `Varchar(10)` formatted user identifier to an integer in MS SQL Server while avoiding schema changes. --- This video is based on the question https://stackoverflow.com/q/68986665/ asked by the user 'Jason' ( https://stackoverflow.com/u/16788833/ ) and on the answer https://stackoverflow.com/a/68987829/ provided by the user 'allmhuran' ( https://stackoverflow.com/u/7165279/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions. Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: MS SQL Obfuscation of Varchar(10) to Integer and back? Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l... The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license. If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com. --- Converting Varchar(10) to Integer in MS SQL Server When working with databases, it's common to encounter the need to convert data types for various purposes. If you're using MS SQL Server and find yourself needing to convert a Varchar(10) identifier formatted as 'AA111X' into an integer, you may face some unique challenges, especially if the existing means of acquiring the corresponding integer values have been discontinued. In this guide, we will explore how to effectively convert a Varchar(10) to an integer without requiring changes to the database schema. Understanding the Problem The need to convert the Varchar(10) involves a format consisting of: The first two characters as letters (alpha) The next three characters as digits (numeric) The last character is alphanumeric For example, the identifier 'AA111X' includes: AA (2 alpha characters) 111 (3 numeric characters) X (alphanumeric character) The Goal The primary goal is to: Create a unique integer representation of this Varchar(10) format Ensure that the integer can be converted back to the original Varchar(10) value, if needed Possible Solutions Requirements Clarification Before diving into the solution, it’s essential to clarify what you require: Unique Integer: Do we only need any unique representation, or do we need specific conditions on the conversion such as case sensitivity or treating characters as values in different bases (e.g., base 26 for letters and base 36 for alphanumeric)? Reversibility: Should the conversion be reversible? If the latter option is true and the existing values are treated as case insensitive (i.e., AA is equivalent to aa), we can create a simple solution that fits well into a 4-byte integer. The Conversion Process Here’s a step-by-step breakdown of converting your Varchar(10) to an integer: Extract Character Values: Use the SQL Server ASCII function to get values of the first two characters. Combine with Numeric Values: Concatenate these values with the numeric part of your Varchar(10) identifier. Add the Last Character: Finally, incorporate the last character using the same ASCII function to complete the concatenation. SQL Code Example Here is a simple SQL code snippet to achieve this conversion: [[See Video to Reveal this Text or Code Snippet]] Explanation of SQL Code: Declare a Variable: -val contains our initial Varchar(10). Select Statement: This creates a new integer by casting and concatenating the ASCII values of the first two characters and the substring of numeric values, plus the ASCII value of the last character. Upper Function: This ensures character case insensitivity by converting the input to uppercase. Conclusion While converting a Varchar(10) to an integer in MS SQL Server may seem daunting due to formatting complexities, using the approach outlined above will allow you to create a unique integer representation efficiently and without the need for a schema change. This method ensures that the data remains manipulatable and corresponds back to its original format should that be necessary in the future. By understanding both the problem and solution, you can effectively navigate the challenges of data type conversions in your SQL Server environment. Remember, the key phrase is: Create a unique integer representation without schema change!