使用apache Derby的WHERE子句上的SQL语法错误

Question

For the following SQL select statement ; -

resultSet = statement.executeQuery("SELECT SS100.ORDERS.ORDER_ID, SS100.ORDERS.ORDER_NUMBER," +" SS100.ORDERS.PERSON_ID, SS100.PERSON.FIRST_NAME"+
"FROM  PERSON, ORDERS " +
"WHERE SS100.PERSON.PERSON_ID = SS100.ORDERS.PERSON_ID " );

I'm getting a syntax error on the WHERE keyword - dump as follows :-

 java.sql.SQLSyntaxErrorException: Syntax error: Encountered "WHERE" at line 1, column 126.
    at org.apache.derby.impl.jdbc.SQLExceptionFactory40.getSQLException(Unknown Source)
    at org.apache.derby.impl.jdbc.Util.generateCsSQLException(Unknown Source)
    at org.apache.derby.impl.jdbc.TransactionResourceImpl.wrapInSQLException(Unknown Source)
    at org.apache.derby.impl.jdbc.TransactionResourceImpl.handleException(Unknown Source)
    at org.apache.derby.impl.jdbc.EmbedConnection.handleException(Unknown Source)
    at org.apache.derby.impl.jdbc.ConnectionChild.handleException(Unknown Source)
    at org.apache.derby.impl.jdbc.EmbedStatement.execute(Unknown Source)
    at org.apache.derby.impl.jdbc.EmbedStatement.executeQuery(Unknown Source)
    at Database.orderQuery(Database.java:146)
    at MainApp.main(MainApp.java:19)

Caused by: java.sql.SQLException: Syntax error: Encountered "WHERE" at line 1, column 126.
at org.apache.derby.impl.jdbc.SQLExceptionFactory.getSQLException(Unknown Source)
at org.apache.derby.impl.jdbc.SQLExceptionFactory40.wrapArgsForTransportAcrossDRDA(Unknown Source)... 10 more

I've tried playing around with the alias statement, but then get an error on the '.' dot operator. I'm obviously doing something fundamentally wrong but I can't see it at the moment, can anyone help?

Answer 1

Look here:

resultSet = statement.executeQuery("SELECT ..." +... + " SS100.ORDERS.PERSON_ID, SS100.PERSON.FIRST_NAME"+
    "FROM  PERSON, ORDERS " +

There's no space between "SS100.PERSON.FIRST_NAME" and "FROM" .

This can be easily solved by always starting your parts with an space:

resultSet = statement.executeQuery("SELECT ..." +... + " SS100.ORDERS.PERSON_ID, SS100.PERSON.FIRST_NAME"+
    " FROM  PERSON, ORDERS " +
    " WHERE ..."

Answer 2

This concatenation of strings will turn into

"SELECT SS100.ORDERS.ORDER_ID, SS100.ORDERS.ORDER_NUMBER," +" SS100.ORDERS.PERSON_ID, SS100.PERSON.FIRST_NAME"+

"FROM PERSON, ORDERS " + "WHERE SS100.PERSON.PERSON_ID = SS100.ORDERS.PERSON_ID "

SELECT SS100.ORDERS.ORDER_ID, SS100.ORDERS.ORDER_NUMBER, SS100.ORDERS.PERSON_ID,
SS100.PERSON.FIRST_NAMEFROM  PERSON, ORDERS WHERE SS100.PERSON.PERSON_ID =
SS100.ORDERS.PERSON_ID

The issue is where FIRST_NAME and FROM join. Add a space after FIRST_NAME and the sql should run fine.

However, you should really be asking yourself why you are doing this. If you know the values to concatenate, why not have one string to start with.