Sql standard to escape column names?

Delving into the world of SQL identifier delimiters

Working with multiple SQL databases often means having to navigate their unique rules. Although the SQL:1999 standard dictates double quotes (") for escaping column names, typical usage varies across different databases.

Database-Specific Identifier Delimiters

• MySQL: Primarily uses backticks ( ), but can be configured to use double quotes via the ANSI_QUOTES mode.
• SQL Server: Favors square brackets ([ ]), but allows double quotes when QUOTED_IDENTIFIER is activated.
• SQLite: Fully compliant with the SQL standard, accepting double quotes without any extra settings.
• Oracle and PostgreSQL: Both adhere to the standard and use double quotes without any additional configuration.

Crafting Cross-Database Compatible Queries

In an environment with an intricate web of interconnected databases, cross-database compatibility can be daunting due to varying identifier delimiters. Understanding and using each database's identifier delimiters is paramount.

In-depth Information on SQL Identifier Delimiters

Being Literally Correct with Identifiers

Correctly utilizing escaping methods is crucial to avoid SQL errors and ensure format compatibility across databases when identifiers could be misconstrued by the SQL engine.

When Must You Escape?

1. Reserved Words: When identifiers coincide with SQL reserved keywords, e.g., "table" or "select". Escaping prevents misinterpretation.
2. Special Characters: If identifiers contain spaces, punctuation, or any other non-alphanumeric characters, then escaping is necessary.
3. Case Sensitivity: Some databases like PostgreSQL treat unquoted names as lowercase, hence "MyColumn" differs from "mycolumn".

Special Characters – Special Handling

Identifiers with special characters require escaping since characters like spaces or hyphens (-) would break the syntax.

Comparing identifier escaping practices across databases

Here are a few examples of how to appropriately escape identifiers in various SQL databases. Remember, SQL loves consistency!

• MySQL with ANSI_QUOTES enabled: // So SQL walks into a bar and sees two tables...

  SELECT "order", "user" FROM "data";  //and says "JOIN me!"
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• PostgreSQL & Oracle: // A SQL query walks into a bar...

  SELECT "order", "user" FROM "data";  //and says "Can I JOIN you?"
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• SQL Server: // What do you call a row in SQL that's moving around the room?

  SELECT [order], [user] FROM [data];  // A "cursor"
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Follow the right practices and ensure your SQL queries are maintainable and clear to anyone who encounters your code.