com.mysql.jdbc.exceptions.MySQLSyntaxErrorException when using PreparedStatement

I am trying to execute a query that returns a student whose name and last name concatenated equal the search key parameter.

For that I am doing this in my class that manages anything related to the database for my Student class.

Student

When the query is executed I am getting the error that follows:

com.mysql.jdbc.exceptions.MySQLSyntaxErrorException:

com.mysql.jdbc.exceptions.MySQLSyntaxErrorException:

What's wrong? I have checked that's the correct way to use concat.

concat

name and lastName are VARCHAR in the mysql database.

name

lastName

VARCHAR

public static Student findStudent(String key)
if (key == null) return null;

PreparedStatement preparedStatement = null;
ResultSet rs = null;

String selectSQL = "select * from project.students where concat(name, lastName) = ? ;";

try
dbConnection = getDBConnection();

preparedStatement = dbConnection.prepareStatement(selectSQL);
preparedStatement.setString(1, key);

Student student = null;
rs = preparedStatement.executeQuery(selectSQL);
if (rs.next())
StudentDB.setStudentAttributes(student, rs);


return student;
catch(SQLException e)
e.printStackTrace();
finally
close();
try
if (preparedStatement != null) preparedStatement.close();
if (rs != null) rs.close();
catch(SQLException e)
e.printStackTrace();


return null;



throw new RuntimeException(e);

.executeUpdate()

StudentDB

.setStudentAttributes

1 Answer
1

Your problem is that you prepare the statement with

preparedStatement = dbConnection.prepareStatement(selectSQL);


which is correct, but then when you try to execute the PreparedStatement you supply the selectSQL string again:

selectSQL

rs = preparedStatement.executeQuery(selectSQL);


That is incorrect. You've already prepared the statement, so when the time comes to execute it you just do

rs = preparedStatement.executeQuery();


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