String Functions

SQL · Methods reference

SQL · Methods reference

📋 Overview

String manipulation — names vary slightly by dialect.

🔧 Methods

Standard / common

Function	Description
`CONCAT(a, b, …)` / `
`LENGTH` / `CHAR_LENGTH`	Character length
`LOWER` / `UPPER`	Case conversion
`TRIM` / `LTRIM` / `RTRIM`	Remove whitespace/chars
`SUBSTRING(str FROM start FOR len)`	Extract substring
`REPLACE(str, from, to)`	Replace occurrences
`POSITION(sub IN str)` / `INSTR`	Find substring index
`LPAD` / `RPAD`	Pad to length
`SPLIT_PART(str, delim, n)` (PG)	Nth split segment
`REGEXP_REPLACE` / `REGEXP_MATCHES` (PG)	Regex ops

💡 Examples

See parent topic notes for runnable snippets; this page is the complete method index.

⚠️ Pitfalls

Mutating methods return None in Python — do not chain sort() / reverse() expecting a new list.
Default JS sort() compares strings — pass (a,b) => a-b for numbers.
SQL function names differ by dialect — verify Postgres vs MySQL docs.
Django QuerySet.update() skips save() signals and auto auto_now fields on models.

Built-in functions

Date & Time Functions

SQL · Methods reference

Window Functions

SQL · Methods reference

On this page

📋 Overview 🔧 Methods Standard / common 💡 Examples ⚠️ Pitfalls 🔗 Related