Can Multiple SQL Statements Be Executed in a Single mysql_query() Call?

Multiple SQL Statements in a Single mysql_query()

Performing multiple SQL statements simultaneously using a single mysql_query() function call is not possible in the standard MySQL API. This is to prevent malicious users from executing arbitrary SQL statements and potentially compromising the database.

While this limitation may discourage some users, it's important to emphasize that it serves as a security measure against SQL injection attacks. By limiting the ability to execute multiple statements, the possibility of attackers exploiting vulnerabilities and gaining unauthorized access to sensitive data is reduced.

However, there are alternative approaches to execute multiple statements atomically. One method is to employ transactions. By enclosing multiple statements within a transaction block, you can ensure that all statements are executed successfully or none at all. This provides a level of atomicity and data integrity that is not possible with individual mysql_query() calls.

For example, to perform the two UPDATE statements mentioned in the question within a single transaction, you can use the following code:

mysql_query("BEGIN TRANSACTION");
mysql_query("UPDATE table SET name = 'bob' WHERE name = 'jim'");
mysql_query("UPDATE table SET age = 55 WHERE name = 'jim'");
mysql_query("COMMIT TRANSACTION");

By wrapping the statements within a transaction, you ensure that either both statements are executed successfully or neither is executed. This approach provides greater control and prevents partial updates or other undesirable outcomes.

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