Is SQL Syntax Case-Sensitive: A Guide to Keywords, Tables, and Columns?

Case sensitivity of SQL syntax

The SQL standard states that keywords such as SELECT, FROM, and WHERE are not case-sensitive, although convention generally dictates that they be capitalized. However, this does not apply to all elements of SQL syntax.

Table name and column name

Table and column names are generally case-sensitive, but there are some exceptions.

• MySQL: Case sensitivity of table and column names is configurable. By default, it is case-insensitive on Windows and case-sensitive on Linux.
• SQL Server: Case sensitivity is determined by the database's collation settings and can be modified at creation time or later.

Example:

CREATE TABLE Employee (
   EmployeeId INT NOT NULL,
   LastName VARCHAR(50) NOT NULL,
   FirstName VARCHAR(50) NOT NULL
);

In SQL Server, if the database collation is set to case-sensitive, the following query will fail:

SELECT * FROM employee;

But the following query will succeed:

SELECT * FROM employee;

Influence

Understanding case sensitivity is critical for interacting with databases. Queries and database objects must respect defined case sensitivities to avoid errors or unexpected behavior.

The above is the detailed content of Is SQL Syntax Case-Sensitive: A Guide to Keywords, Tables, and Columns?. For more information, please follow other related articles on the PHP Chinese website!