SQL Server String ASCII() Function

SQL Server ASCII() Function

The SQL Server ASCII() function is used to return the ASCII code of the first character in a string. This function is useful for data processing and manipulation tasks where you need to work with ASCII values.

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Syntax

SELECT ASCII(string_expression);

The ASCII() function takes a single argument:

• string_expression: The string from which to retrieve the ASCII code of the first character.

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Example SQL Server ASCII() Function Queries

Let's look at some examples of SQL Server ASCII() function queries:

1. Basic ASCII() Example

SELECT ASCII('A') AS ascii_value;

This query returns the ASCII code of the character 'A'. The result will be:

ascii_value
------------
65

2. ASCII() with a String

SELECT ASCII('Hello') AS ascii_value;

This query returns the ASCII code of the first character in the string 'Hello'. The result will be:

ascii_value
------------
72

3. ASCII() with a Variable

DECLARE @myString VARCHAR(50);
SET @myString = 'SQL Server';
SELECT ASCII(@myString) AS ascii_value;

This query uses a variable to store a string and then retrieves the ASCII code of the first character in the string 'SQL Server'. The result will be:

ascii_value
------------
83

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Full Example

Let's go through a complete example that includes creating a table, inserting data, and using the ASCII() function.

Step 1: Creating a Table

This step involves creating a new table named example_table to store some sample data.

CREATE TABLE example_table (
    id INT PRIMARY KEY,
    description VARCHAR(50)
);

In this example, we create a table named example_table with columns for id and description.

Step 2: Inserting Data into the Table

This step involves inserting some sample data into the example_table.

INSERT INTO example_table (id, description) VALUES (1, 'Apple');
INSERT INTO example_table (id, description) VALUES (2, 'Banana');
INSERT INTO example_table (id, description) VALUES (3, 'Cherry');

Here, we insert data into the example_table.

Step 3: Using the ASCII() Function

This step involves using the ASCII() function to retrieve the ASCII code of the first character in the description column.

SELECT id, description, ASCII(description) AS ascii_value
FROM example_table;

This query retrieves the id, description, and the ASCII code of the first character in the description column for each row in the example_table. The result will be:

id  description  ascii_value
--- ------------ ------------
1   Apple        65
2   Banana       66
3   Cherry       67

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Conclusion

The SQL Server ASCII() function is a powerful tool for retrieving the ASCII code of the first character in a string. Understanding how to use the ASCII() function and its syntax is essential for effective data processing and manipulation in SQL Server.