Like Statement in PostgreSQL | Using LIKE to find Patterns

2026-06-16 · Source: Alex The Analyst · Field: Technology & Digital — Software Development & Engineering, Data Science & Analytics · Depth: Novice, medium

Summary

The PostgreSQL "LIKE" statement enables powerful pattern searching within data using two primary wildcards: the percent sign ("%") for any sequence of zero or more characters, and the underscore ("_") for any single character. This functionality is demonstrated for finding character names that start with, contain, or end with specific letters, emphasizing the case-sensitive nature of "LIKE" operations. For instance, "L%" finds names starting with "L" (e.g., Luke, Leia), while "%l%" (lowercase) finds names containing "l" (e.g., Padme Amidala, Han Solo, Darth Maul). The article also illustrates an advanced technique: type casting date columns to text (e.g., "birth_date::text") to apply "LIKE" for pattern matching on dates, such as finding entries from "1977", which is otherwise not directly supported on date types.

Key takeaway

For data analysts or engineers needing flexible data retrieval in PostgreSQL, master the "LIKE" operator with its "%" and "_" wildcards. This allows you to efficiently find patterns like names starting with "L" ("L%") or specific date ranges by type casting (e.g., "birth_date::text LIKE '1977%'"). Be mindful of "LIKE"'s case sensitivity; plan for string functions in advanced scenarios to normalize text for consistent results.

Key insights

The PostgreSQL "LIKE" operator, with "%" and "_" wildcards, enables flexible pattern matching for data retrieval.

Principles

• "LIKE" operations are case-sensitive.
• Type casting extends "LIKE" to non-string data.

Method

Apply WHERE column LIKE 'pattern' using '%' for multi-character and '_' for single-character wildcards. For date columns, cast to text (e.g., column::text) before applying "LIKE" for pattern matching.

In practice

• Use "L%" to find strings starting with "L".
• Apply "column::text LIKE 'YYYY%'" for date range filtering.

Topics

• PostgreSQL
• SQL LIKE Operator
• Pattern Matching
• SQL Wildcards
• Data Querying
• Type Casting

Best for: Data Scientist, Data Engineer, Data Analyst

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Editorial summary, takeaway, and curation by AIssential. Original article published by Alex The Analyst.