Technique for Managing Escape Characters in Data

This article will discuss a technique for managing escape characters in data, with a specific emphasis on the double quote character ("). The expression provided is designed to replace these escaped characters with their original forms, improving the clarity and understand the data. By removing escape characters, we enhance the readability and usability of the data, making it easier to work with and analyze.

The REPLACE() function replaces all occurrences of a substring with a new one in a string.

Syntax

REPLACE(source, from_text, to_text);

Explanation:

• The REPLACE() function accepts three arguments:
  • source: This is the input string that you wish to substitute.
  • from_text: This is the specific substring that you wish to search for and replace. In the event that the from_text is present multiple times within the source string, the function will replace all instances.
  • to_text: This is the new substring that you wish to substitute in place of the from_text.

Data includes Escape Characters:

Below is a sample of data that includes escape characters.
Example: 1

    "Hello, \"World\"!"
    "Escape characters: $$\"$$ and \$$\"$$

Output:
The output shows the result after using the given expression to eliminate escape characters.

Hello, "World"!
Escape characters: "$" and "$"

Example: 2

replace (replace (replace (data_with_escape::text, '\"', '"'), $$"\$$, '"'),'\n','')

• data_with_escape::text: This converts the value of data_with_escape to text data type.
• data_with_escape is a variable or column in a database table.
• The first replace function is replacing occurrences of " with ". As mentioned earlier, " is commonly used to represent a double quote character that’s escaped within a string.
• The second replace function is replacing occurrences of $$"$$ with ". In dollar-quoting, the dollar signs ($$) are used to delimit string literals. So $$"$$ represents a dollar-sign-enclosed double quote character, indicating an escaped double quote.

Additional References

• Configuring Expression Columns