I have one partitioned table 'table1' and I'm able to run select clause on this table in Athena and it gives result as well.
However, when I try to run the query on this Table 'table1' using Lambda Function, it gives me the following Error
'SYNTAX_ERROR: line 1:8: SELECT * not allowed from relation that has no columns'
Below is the python script of Lambda
client = boto3.client('athena')
#Setup and Perform query
response = client.start_query_execution(
QueryString = 'Select * FROM table1',
QueryExecutionContext = {
'Database' : 'test'
},
ResultConfiguration = {
'OutputLocation': 's3://test/'
}
)
Related
we are connecting to our Postgresql (RDS) server from our django backend as well as lambda, sometimes django backend queries time out and I run the following query to see the locks:
SELECT
pg_stat_activity.client_addr,
pg_stat_activity.query
FROM pg_class
JOIN
pg_locks ON pg_locks.relation = pg_class.oid
JOIN
pg_stat_activity ON pg_locks.pid =
pg_stat_activity.pid
WHERE
pg_locks.granted='t' AND
pg_class.relname='accounts_user'
This gives me 30 rows of simple select queries executed from lambda like this:
SELECT first_name, picture, username FROM accounts_user WHERE id = $1
why does this query hold a lock? should I be worried?
I'm using pg8000 library to connect from Lambda
with pgsql.cursor() as cursor:
cursor.execute(
"""
SELECT first_name, picture, username
FROM accounts_user
WHERE id = %s
""",
(author_user_id,),
)
row = cursor.fetchone()
# use the row ..
I opened an issue at Github maybe it's because I'm using the library wrong. https://github.com/tlocke/pg8000/issues/16
You can also try to reuse the database connection, see https://docs.djangoproject.com/en/2.2/ref/settings/#conn-max-age
DATABASES = {
'default': {
...
'CONN_MAX_AGE': 600, # reuse database connection
}
}
I have a query which contains two part. First part call function which creates a temporary table, second part select data from this table.
SELECT create_data_slice(15962, NULL, ARRAY[[15726]]);
SELECT
AK."15962_15726" as AK_NAME
FROM
t15962 AK
GROUP BY
AK."15962_15726;"
If I execute this query in PgAdmin, it turns right result with data. But if I execute it in Qt:
QSqlDatabase db = store->get_db();
QSqlQuery query(db);
query.exec(sql);
it executes only the first part (create temporary table), but do not execute second part and do not return data.
You can use a transaction like this:
QSqlDatabase::database().transaction();
QSqlQuery query;
query.exec("SELECT create_data_slice(15962, NULL, ARRAY[[15726]]);");
if (query.next())
{
int employeeId = query.value(0).toInt();
query.exec("SELECT AK."15962_15726" as AK_NAME FROM t15962 AK GROUP BY AK."15962_15726;");
while(query.next())
{
qDebug() << query.value().toString(); ///or what you want to do with data
}
}
QSqlDatabase::database().commit();
I created a temporary table with sqlalchemy (with an underlying postgres database) that is going to be joined with a database table. However, in some cases when a value is empty '' then postgres throws the error:
failed to find conversion function from unknown to text
SqlAlchemy assembles everything to the following context
[SQL: 'WITH temp_table AS \n(SELECT %(param_1)s AS id, %(param_2)s AS email, %(param_3)s AS phone)\n SELECT campaigns_contact.id, campaigns_contact.email, campaigns_contact.phone \nFROM campaigns_contact JOIN temp_table ON temp_table.id = campaigns_contact.id AND temp_table.email = campaigns_contact.email AND temp_table.phone = campaigns_contact.phone'] [parameters: {'param_1': 83, 'param_2': '', 'param_3': '+1234567890'}]
I assemble the temporary table as follows
stmts = []
for row in import_data:
row_values = [literal(row[value]).label(value) for value in values]
stmts.append(select(row_values))
subquery = union_all(*stmts)
subquery = subquery.cte(name="temp_table")
The problem seems to be the part here
...%(param_2)s AS email...
which after replacing the param_2 results in
...'' AS email...
which will cause the error mentioned above.
One way to solve the issue is to perform a cast
...''::text AS email...
However, I don't know how to perform ::text cast with sqlalchemy!?
How to execute the following query
select * from table1 union select * from table2
in zend-framework2 where i am using tablegateway? In the documentation of zf2,they didn't give any details about union query.
Try -
$select1 = new Select('table1');
[.... rest of the code ....]
$select2 = new Select('table2');
[.... rest of the code ....]
$select1->combine($select2); //This will create the required SQL union statement.
To get count of the two tables you have to use a bit of SQL rather then tableGateway -
$sql = new Sql($this->tableGateway->adapter);
$select_string = $sql->getSqlStringForSqlObject($select1);
$sql_string = 'SELECT * FROM (' . $select_string . ') AS select_union';
$statement = $this->tableGateway->adapter->createStatement($sql_string);
$resultSet = $statement->execute();
$total_records = count($resultSet);
$resultSet gives data.
$total_records gives total no. of records.
I have a database in postgreSQL. I want to read some data from there, but I get an error (column anganridref does not exist) when I execute my command.
Here is my NpgsqlCommand:
cmd.CommandText = "select * from angebot,angebotstatus,anrede where anrid=anganridref and anstaid=anganstaidref";
and my 3 tables
the names of my columns are rights. So I don't understand why that error comes. Someone can explain me why it does crash? Its not the problem of large and lowercase.
You are not prefixing your column names in the where clause:
select *
from angebot,
angebotstatus,
anrede
where anrid = anganridref <-- missing tablenames for the columns
and anstaid = anganstaidre
It's also recommended to use an explicit JOIN instead of the old SQL 89 implicit join syntax:
select *
from angebot
join angebotstatus on angebot.aaaa = angebotstatus.bbbb
join anrede on angebot.aaaa = anrede.bbbb