#99 Allow sub-queries in SQL FROM clause

[Simon Chenery]

Allow sub-queries in the FROM clause of SQL statements. For example,

SELECT ID FROM (SELECT ID FROM sample) AS X

CsvJdbc currently throws an SQLException for this SQL statement, without any helpful information in the error message.

java.sql.SQLException: Syntax error: Encountered " "FROM" "FROM "" at line 1, column 27.
Was expecting:
<EOF>

at org.relique.jdbc.csv.CsvStatement.executeQuery(CsvStatement.java:298)
at org.relique.jdbc.csv.Runner2.main(Runner2.java:64)

[Simon Chenery]

Originally reported in csvjdbc-develop forum topic message for queries on derived tables .

[Simon Chenery]

Provide readable "derived tables not supported" error message if derived table used in SQL SELECT statement.

Added unit test TestSubQuery.testDerivedTable.

Files changed:
src/main/java/org/relique/jdbc/csv/ParsedStatement.java
src/main/java/org/relique/jdbc/csv/ParsedTable.java
src/main/java/org/relique/jdbc/csv/SqlParser.java
src/main/javacc/org/relique/jdbc/csv/where.jj
src/main/resources/org/relique/jdbc/csv/messages.properties
src/test/java/org/relique/jdbc/csv/TestSubQuery.java