Database Essentials - Predefined Functions - String Replacement

This article covers essential string manipulation functions in SQL, including case conversion, length retrieval, data extraction, trimming, padding, reversing strings, concatenating strings, position identification, and string replacement. The key concepts are explained in simple language with code examples for each function.

Explanation for the video:
This article is based on a video tutorial available on YouTube. The embedded video provides a visual demonstration of how to perform string manipulation functions in SQL. Watching the video complements the text by offering a practical demonstration of the concepts discussed.

Key Concepts Explanation

Case Conversion and Length

String manipulation functions like lower, upper, initcap, and length are explored in this section. Case conversion and length retrieval examples are provided with code snippets.

Extracting Data - substr and split_part

The usage of substr, substring, and split_part functions to retrieve specific data from strings is demonstrated. Code examples show how to extract substrings and split strings based on delimiters.

Using position or strpos

Functions like position and strpos are introduced to find the position of a substring within a main string. Examples show how to identify substrings like email ids in strings.

Trimming and Padding Functions

The functions ltrim, rtrim, trim, lpad, and rpad are explained for removing spaces and padding strings. Code examples illustrate trimming leading/trailing spaces and padding strings with characters.

Reverse and Concatenating multiple strings

The reverse, concat, and concat_ws functions are covered in this section for reversing strings and concatenating multiple strings. Examples showcase how to reverse strings and concatenate strings with specific separators.

String Replacement

String replacement functions like replace and translate are discussed for replacing characters in strings. Code examples demonstrate replacing specific characters and overlaying characters in strings.

Hands-On Tasks

  1. Perform case conversion on a sample string using lower and upper functions.
  2. Extract specific data from a string using substr and split_part functions.
  3. Identify the positions of characters within a string using position or strpos functions.
  4. Trim leading and trailing spaces in a string using ltrim and rtrim functions.
  5. Pad numbers with zeros in strings using lpad function.
  6. Reverse a sample string using the reverse function.
  7. Concatenate multiple strings with and without separators using concat and concat_ws functions.
  8. Replace specific characters in a string using the replace function.
  9. Translate characters in a string to replace them with specific values using the translate function.


This article delves into the world of string manipulation functions in SQL, providing a comprehensive understanding of how to manipulate strings efficiently. By practicing the hands-on tasks and exploring the examples, readers can enhance their SQL skills and apply these concepts to real-world scenarios for data transformation and analysis. Remember to engage with the community for further learning and share your experiences with string manipulation functions in SQL.

Watch the video tutorial here