Backticks vs. Square Brackets in SQL: Which Identifier Quote Should I Use?

SQL Statement Markup: Backticks vs. Square Brackets

When defining field names or table names in SQL statements, developers often enclose them in characters to safeguard against reserved keywords or special characters. In MySQL, this is typically done with backticks (``), while in SQL Server or MS Access, square brackets ([]) are used.

Compatibility Differences

The primary distinction between backticks and square brackets lies in their database compatibility. Backticks are exclusive to MySQL, whereas square brackets are utilized by SQL Server/T-SQL and MS Access. Therefore, employing backticks in SQL Server may result in syntax errors.

Understanding Backticks in MySQL

In MySQL, backticks serve as the identifier quote character. They allow developers to enclose any table or field name that would otherwise conflict with a reserved keyword, casing sensitivity, or contain special characters.

Example:

SELECT * FROM `select` WHERE `select`.id > 100;

ANSI_QUOTES Consideration

MySQL also supports quoting identifiers within double quotation marks when the ANSI_QUOTES SQL mode is enabled.

Example:

SET sql_mode='ANSI_QUOTES';
CREATE TABLE "test" (col INT);

Conclusion

While backticks and square brackets both achieve the purpose of safeguarding field and table names, their use depends on the specific database technology being employed. For MySQL, backticks should be used exclusively, while for SQL Server or MS Access, square brackets are the appropriate choice.

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