The difference between SQL single quotes and double quotes
In SQL, single quotes are used to enclose strings to represent their literal values. Unlike many other programming languages that use double quotes, SQL generally does not recognize double quotes.
Main differences:
- Single quotes: is used to represent strings and is required.
- Double quotes: is not usually used by SQL.
Use of single quotes:
- Enclose string literals: 'This is a string'
- Column alias: SELECT column_name AS 'alias'
Example:
SELECT product_name AS '产品名称' FROM Products;
Other instructions:
- Some specific database implementations may support double quotes, but this is not standard usage.
- Single quotes are required when column aliases contain spaces, but this is not recommended.
- For consistency and best practice, it is recommended to always use single quotes around strings in SQL.
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