How to Safely Use Variables in Python SQL Statements?

Using Variables in SQL Statements in Python

When working with database operations in Python, it's often necessary to incorporate variables into SQL statements. However, if these variables are directly embedded into the query text, Python will interpret them as part of the query, which can lead to unexpected results.

To avoid this issue, variables should be passed as parameters to the SQL statement. The preferred method for achieving this is to use placeholders in the query and pass the values as a tuple:

cursor.execute("INSERT INTO table VALUES (%s, %s, %s)", (var1, var2, var3))

In this example:

• The query text contains placeholders (%s) to represent where the variable values should be inserted.
• The values (var1, var2, var3) are passed as a tuple to the execute() method.

The database API handles the proper escaping and quoting of the values, ensuring their safe insertion into the database.

It's important to note that using string formatting operators like (%) to insert variables is not recommended as it doesn't provide proper escaping, which can lead to security vulnerabilities like SQL injection attacks.

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