String Functions (UPPER, LOWER, TRIM, SUBSTRING, REPLACE)

SQL provides built-in string functions to manipulate text data easily.

Common String Functions

• UPPER(text) — Converts all letters to uppercase
• LOWER(text) — Converts all letters to lowercase
• TRIM(text) — Removes leading and trailing spaces
• SUBSTRING(text, start, length) — Extracts a portion of a string
• REPLACE(text, old, new) — Replaces occurrences of a substring with another

Example: Clean and Format Names

To display student names in uppercase and remove extra spaces:

SELECT UPPER(TRIM(name)) FROM students;

You can combine functions to format or clean data for reports and analysis.

Try using these functions to manipulate text fields in your queries!

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