Comment in beggining of SQL statement returns empty recordSet. In clickhouse-client works OK. #233
Description
When we provide Sql statement with comment in clickhouse-client it works. - no matter if comment is at the begining or at the end of sql statement.
docker run --rm yandex/clickhouse-client -h ch8.local -q "select * from system.numbers limit 3 /*comment*/"
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uporabnik@lju1135:~$ ^C
uporabnik@lju1135:~$ docker run --rm yandex/clickhouse-client -h ch8.local -q "/*comment*/select * from system.numbers limit 3"
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When running clickhouse-jdbc and we use comment at the beggining it FAILS
@Test
public void clickhouseJdbcFailsBecauseOfCommentInStart() throws Exception {
Connection connection = DriverManager.getConnection("jdbc:clickhouse://ch8:8123/test4ssp?dataTransferTimeout=600&connection_timeout=5000");
String sqlStatement = "/*comment*/ select * from system.numbers limit 3";
try (Statement statement2 = connection.createStatement()) {
try (ResultSet resultSet2 = statement2.executeQuery(sqlStatement)) {
if (resultSet2 == null) {
Assert.assertTrue(false);
throw new Exception("resultset was null");
} else {
while (resultSet2.next()) {
System.out.println(resultSet2.getString(1));
}
Assert.assertTrue(true);
}
}
}
}
and if we supply comment at the end of statement if works
@Test
public void clickhouseJdbcPassOkBecauseOfNoCommentInStart() throws Exception {
Connection connection = DriverManager.getConnection("jdbc:clickhouse://ch8/test4ssp?dataTransferTimeout=600&connection_timeout=5000");
String sqlStatement = "select * from system.numbers limit 3 /*comment*/";
try (Statement statement2 = connection.createStatement()) {
try (ResultSet resultSet2 = statement2.executeQuery(sqlStatement)) {
if (resultSet2 == null) {
Assert.assertTrue(false);
throw new Exception("resultset was null");
} else {
while (resultSet2.next()) {
System.out.println(resultSet2.getString(1));
}
Assert.assertTrue(true);
}
}
}
}
Why is this a problem? We normally add some small comments above sql statements in order to describe statement.