public void test_1() throws Exception {
String sql = "(select * from a) union select * from b";
PGSQLStatementParser parser = new PGSQLStatementParser(sql);
List<SQLStatement> statementList = parser.parseStatementList();
SQLStatement statemen = statementList.get(0);
// print(statementList);
Assert.assertEquals(1, statementList.size());
assertTrue(statemen instanceof PGSelectStatement);
PGSelectStatement select = (PGSelectStatement) statemen;
assertTrue(select.getSelect().getQuery() instanceof SQLUnionQuery);
SQLUnionQuery unionQuery = (SQLUnionQuery) select.getSelect().getQuery();
assertTrue(unionQuery.getLeft() instanceof SQLSelectQueryBlock);
assertTrue(unionQuery.getRight() instanceof SQLSelectQueryBlock);
SQLSelectQueryBlock leftQueryBlock = (SQLSelectQueryBlock) unionQuery.getLeft();
assertTrue(leftQueryBlock.isParenthesized());
}
public SQLSelectQuery queryRest(SQLSelectQuery selectQuery) {
if (lexer.token() == (Token.UNION)) {
SQLUnionQuery union = new SQLUnionQuery();
union.setLeft(selectQuery);
lexer.nextToken();
if (lexer.token() == (Token.ALL)) {
union.setOperator(SQLUnionOperator.UNION_ALL);
lexer.nextToken();
}
SQLSelectQuery right = query();
union.setRight(right);
return queryRest(union);
}
if (lexer.token() == Token.INTERSECT) {
lexer.nextToken();
SQLUnionQuery union = new SQLUnionQuery();
union.setLeft(selectQuery);
union.setOperator(SQLUnionOperator.INTERSECT);
SQLSelectQuery right = this.query();
union.setRight(right);
return union;
}
if (lexer.token() == Token.MINUS) {
lexer.nextToken();
SQLUnionQuery union = new SQLUnionQuery();
union.setLeft(selectQuery);
union.setOperator(SQLUnionOperator.MINUS);
SQLSelectQuery right = this.query();
union.setRight(right);
return union;
}
return selectQuery;
}