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How to deal with SQL column names that look like SQL keywords?

sql
sql-keywords
sql-escaping
sql-design
Anton ShumikhinbyAnton Shumikhin·Oct 27, 2024
TLDR

Escape column names that clash with SQL keywords using delimiters. In MySQL, apply backticks (`), in PostgreSQL and SQL Server with QUOTED_IDENTIFIER, use double quotes ("), and for SQL Server without QUOTED_IDENTIFIER, square brackets ([ ]) work. Here's how to work around a column named order:

-- MySQL: Let's "order" some tacos! SELECT `order` FROM table_name; -- PostgreSQL or SQL Server with QUOTED_IDENTIFIER: Order, order in the court! SELECT "order" FROM table_name; -- SQL Server without QUOTED_IDENTIFIER: Bracketology 101. SELECT [order] FROM table_name;

Avoid using SQL keywords as column names when possible. If unavoidable, these delimiters offer a concrete solution for effective querying.

Practical usage: escaping SQL keywords

When designing databases, avoid naming clashes with SQL keywords. However, at times, clashes are unavoidable. Here, delimiters aid in distinguishing between SQL keywords and column names, keeping your queries concise and conflict-free.

Handling case sensitivity in SQL

PostgreSQL observes case sensitivity when identifiers are enclosed in double quotes. Without quotes, identifiers are forced to lowercase. Recognize and adjust accordingly to preserve the integrity of your queries.

Identifiers in multiple-table scenarios

In situations where your query pulls data from multiple tables with similar column names, confusion can occur. Avoid this by using brackets ([ ]) for SQL Server or double quotes (") for PostgreSQL to clearly identify each column and its related table.

Managing clashes across different SQL implementations

The different mechanisms to escape keywords is one of the challenges in dealing with diverse SQL dialects. PostgreSQL prefers double quotes, whereas SQL Server leans towards brackets. Understand these differences, adapt your strategy, and write compatible cross-platform queries.

In MySQL, your current SQL mode set affects the way reserved keywords are handled. Confirm the mode allows for escaping with backticks, maintaining separation between your identifiers and reserved keywords.

Dodging hidden gotchas: the less obvious SQL keywords

SQL landmines aren't limited to the usual suspects like SELECT, FROM, WHERE. Words like TIMESTAMP and PASSWORD are also classified as reserved. Keep an upto-date list of these reserved words to sidestep potential ambushes in your database designs and SQL queries.