Part 101: String Functions: CONCAT, SUBSTRING, LENGTH, TRIM & CASE

Manipulating textual data directly inside queries.

1. Common String Functions

SELECT 
  -- Concatenation:
  CONCAT(first_name, ' ', last_name) AS full_name,
  first_name || ' ' || last_name AS full_name_pipe_syntax,

  -- Trimming whitespace:
  TRIM('  spaced text  ') AS clean_text,

  -- Case transformations:
  LOWER(email) AS normalized_email,
  UPPER(country_code) AS country_code,

  -- Substrings and Length:
  LENGTH(username) AS char_count,
  SUBSTRING(email FROM 1 FOR 5) AS prefix
FROM users;

Key Takeaways

• Clean, normalize, and concatenate strings within the database before returning to client apps.

In Part 102, we explore Advanced String Manipulation: REPLACE, LPAD, RPAD & STRPOS!