What common syntax errors can occur when writing PHP code for database operations like INSERT statements?

One common syntax error when writing PHP code for database operations like INSERT statements is forgetting to properly concatenate variables into the query string. This can result in a syntax error or unexpected behavior when executing the query. To solve this issue, make sure to properly concatenate variables using the dot (.) operator within the query string.

// Incorrect way without proper concatenation
$query = "INSERT INTO table_name (column1, column2) VALUES ($value1, $value2)";

// Correct way with proper concatenation
$query = "INSERT INTO table_name (column1, column2) VALUES ('" . $value1 . "', '" . $value2 . "')";