How to fix ERROR 1065: Query was empty in MySQL

$query = "SELECT * FROM users WHERE id = " . $userId;
error_log("About to execute: " . $query);
$result = mysqli_query($connection, $query);

const query = "SELECT * FROM users WHERE id = " . userId;
console.log("Query:", query);
db.query(query, (err, results) => { /* ... */ });

query = f"SELECT * FROM users WHERE id = {user_id}"
print(f"Executing query: {query}")
cursor.execute(query)

$query = buildQuery();
if (empty(trim($query))) {
  throw new Exception("Query cannot be empty");
}
mysqli_query($connection, $query);

const query = buildQuery();
if (!query || query.trim().length === 0) {
  throw new Error("Query cannot be empty");
}
db.query(query);

query = build_query()
if not query or not query.strip():
  raise ValueError("Query cannot be empty")
cursor.execute(query)

// Bad: might result in empty WHERE clause
let query = "SELECT * FROM users";
if (hasFilter) {
  query += " WHERE " + filterCondition;
}
// If hasFilter is false, query is fine
// But if filterCondition is empty, you get "SELECT * FROM users WHERE "

// Good: only add WHERE if condition exists
let query = "SELECT * FROM users";
if (hasFilter && filterCondition) {
  query += " WHERE " + filterCondition;
}

CREATE TABLE users (id INT);;
CREATE TABLE posts (id INT);

CREATE TABLE users (id INT);
CREATE TABLE posts (id INT);

query = """
  -- SELECT * FROM users
  -- WHERE active = 1
"""
# If using comment-stripping, this becomes empty!

$stmt = $connection->prepare("SELECT * FROM users WHERE id = ?");
if (!$stmt) {
  throw new Exception("Prepare failed: " . $connection->error);
}
$stmt->bind_param("i", $userId);
if (!$stmt->execute()) {
  throw new Exception("Execute failed: " . $stmt->error);
}

$user = User::find($userId);
// ORM handles query construction and validation