Why does "column does not exist" appear when I use double quotes?

Because double quotes mean "identifier," not "string," in PostgreSQL, SQLite, and SQL Server. When you write WHERE name = "John", the database looks for a column named John instead of comparing against the text John. Switch the value to single quotes ('John') and the error goes away.

Can I use double quotes for strings in MySQL?

Yes, by default MySQL accepts double quotes as string delimiters, so "text" and 'text' both work. But it's not portable — the same query fails in PostgreSQL. If you enable ANSI_QUOTES mode, MySQL treats double quotes as identifiers like the standard. Use single quotes for strings to stay portable.

How do I escape a single quote inside a SQL string?

Double it. To store O'Brien, write 'O''Brien' — two single quotes in a row represent one literal apostrophe. This is the SQL-standard escape and works in every major database. Avoid backslash escaping, which is non-standard and depends on database settings.

What are backticks and square brackets for in SQL?

They're alternative identifier delimiters. MySQL and BigQuery use backticks (`table_name`) to quote identifiers, while SQL Server uses square brackets ([table name]). They serve the same purpose as standard double-quoted identifiers: wrapping a name that contains spaces, special characters, or a reserved keyword.

SQL Dialects

Single vs Double Quotes in SQL: When to Use Each

By Sharon Ben-Moshe · June 25, 2026 · 4 min read

Sharon Ben-Moshe is the founder of sqlfmt, a browser-based SQL formatter and validator with misspelled-keyword suggestions across PostgreSQL, MySQL, SQLite, SQL Server, and BigQuery.

Single quotes are for string values, double quotes are for identifiers — but MySQL, SQL Server, and BigQuery bend the rule. The full guide, with examples.

Quick answer

In standard SQL, single quotes ('text') delimit string and date literals, while double quotes ("name") delimit identifiers like column and table names. So use single quotes for values you're comparing or inserting, and double quotes only when an identifier needs special characters, spaces, or case sensitivity. MySQL is the exception — it treats double quotes as strings unless ANSI_QUOTES mode is on.

Single vs Double Quotes in SQL: When to Use Each

Quick answer

FAQs

Why does "column does not exist" appear when I use double quotes?

Can I use double quotes for strings in MySQL?

How do I escape a single quote inside a SQL string?

What are backticks and square brackets for in SQL?

SQL COALESCE vs ISNULL: Key Differences

SQL ROW_NUMBER(): How to Number Rows

SQL Date Difference: DATEDIFF by Database

What's the difference between single and double quotes in SQL?

Single quotes: string and date literals

Double quotes: identifiers that need protecting

Where the dialects disagree

The classic error: "column does not exist"

Checklist: getting SQL quotes right

Wrapping up

Quick answer

FAQs

Why does "column does not exist" appear when I use double quotes?

Can I use double quotes for strings in MySQL?

How do I escape a single quote inside a SQL string?

What are backticks and square brackets for in SQL?

Keep reading

SQL COALESCE vs ISNULL: Key Differences

SQL ROW_NUMBER(): How to Number Rows

SQL Date Difference: DATEDIFF by Database

What's the difference between single and double quotes in SQL?

Single quotes: string and date literals

Double quotes: identifiers that need protecting

Where the dialects disagree

The classic error: "column does not exist"

Checklist: getting SQL quotes right

Wrapping up