Why doesn't this work (when parameter is set to 1) :
SELECT * FROM TABLE WHERE TIMESTAMPFIELD > (CURRENT_TIMESTAMP - ?)
But this works :
SELECT * FROM TABLE WHERE TIMESTAMPFIELD > (CURRENT_TIMESTAMP - 1)
I get error message: "conversion error from string "39723.991882951" "
I'm using Firebird 2.1
EDIT:
I found the answer myself with a little help:
SELECT * FROM TABLE WHERE TIMESTAMPFIELD > (CURRENT_TIMESTAMP - CAST(? as DECIMAL(18,9))
Works if the parameter is given as float value.
What do you want to do exactly? Maybe I can be more helpfull with more details.
SELECT * FROM TABLE WHERE TIMESTAMPFIELD > (CURRENT_TIMESTAMP - ?)
How do you set your parameter in your code? Which language do you use?
If you use Delphi, then your parameter should be passed as Float. Ie:
MyQuery.ParamByName('delta').asFloat := 0.1;
Try this and tell us if it's working
HTH
Related
SELECT_QUERY = `SELECT * FROM events WHERE c_id = ? AND start_time > ? and
end_time < ?`
query := sr.db.Raw(SELECT_QUERY, request.GetCId(), startTime, endTime)
var v = request.GetVIds()
if len(v) > 0 {
query = query.Where(` v_id IN (?) `, v)
} //Only this block introduces first ) after end_time
var c = request.GetStatus().String()
if len(c) > 0 {
query = query.Where( " status = ? ", c) // this introduces the other opening brace //after AND
}
Following is the query generated and found in logs
SELECT * FROM events WHERE c_id = 1 AND start_time > '2020-04-16 18:42:00' and
end_time < '2020-04-16 18:45:50' ) AND ( v_id IN (1,2)) AND ( status = 'STATUS_MIDDLE_CLASS' ORDER BY start_time DESC LIMIT 5 OFFSET 1
The other solution in stackoverflow and internet article doesn't help.
PS: Is it because I mix db.Raw( ) and query.Where() ?
Changing ? to $1 doesn't fix the issue.
Basically a few things fixed the issue.
1) Mixing Raw and query.Where was one issue.
After making the Raw query to sr.db.Where
2)
SELECT_QUERY = `SELECT * FROM events WHERE c_id = ? AND start_time > ? and
end_time < ?`
already has select * from. And then using query := sr.db.Raw(SELECT_QUERY, request.GetCId(), startTime, endTime) introduces nested select *.
So, changed SELECT_QUERY as follows
SELECT_QUERY = `events WHERE c_id = ? AND start_time > ? and
end_time < ?`
solved the issue.
I found a workaround to the error which I received when I tried to add a timestamp filed in Go/Gorm solution with PostgreSQL equivalent to default: now() which is default: time.Now().Format(time.RFC3339)
I received the error because I use AutoMigrate() to create the tables in PostgreSQL. The one problem I found is when trying to use the default value of a function instead of a string (which one can use for a fixed timestamp).
So I had to go into DataGrid (since I use JetBrains, but you can use any PostgreSQL admin tool like pgAdmin) and manually add the timestamp field with default of now() or merely update the existing field to add the default of now(). Then the error goes away when doing your next build in Go.
i have a starting table where there are some meteo data stored every 15 minutes, one field stores leaf wet at 1 minute sampling in a numeric array form, thus i have a 15 values array each row.
Now i want to create a 1 hour aggregation of this table, crating an array of 60 values for this field.
I tried array_cat at first place, but says
array_cat(numeric[]) not existing
the function obviuously exists, so i tought the format was not the one expected, i tried first unnesting and then aggregating, not working again.
Finally i was able to aggregate trough string conversion, but it's not what i wanted (i might in the future apply some numeric elaboration oh that 60-values array)
I paste the query for further investigations
SELECT dati1_v.id_stazione,
to_char(dati1_v.data_ora, 'YYYY-MM-DD HH24:00:00'::text) AS date_hour,
round(avg(dati1_v.temp1_media), 2) AS t_avg,
round(avg(dati1_v.ur1_media), 2) AS hum_avg,
sum(dati1_v.pioggia) AS rain_tot,
max(dati1_v.pioggia) AS rain_max,
round((avg((SELECT avg(lw.lw) AS avg FROM unnest(dati1_v.lw_top_array) lw(lw))) - lws.top_min) /
(lws.top_max - lws.top_min) * 100::numeric, 2) AS lw_top_avg,
array_agg((SELECT round((avg(lw.lw) - lws.top_min) / (lws.top_max - lws.top_min) * 100::numeric, 2) AS round
FROM unnest(dati1_v.lw_top_array) lw(lw))) AS lw_top_array,
array_cat(dati1_v.lw_top_array) AS lw_top_array_tot,
-- array_agg((select lw_top_array from unnest(dati1_v.lw_top_array))) AS lw_top_array_tot,
-- array_agg(array_to_string(dati1_v.lw_top_array, ',')) AS lw_top_array_tot,
round((avg((SELECT avg(lw.lw) AS avg FROM unnest(dati1_v.lw_bottom_array) lw(lw))) - lws.bottom_min) /
(lws.bottom_max - lws.bottom_min) * 100::numeric, 2) AS lw_bottom_avg,
array_agg((SELECT round((avg(lw.lw) - lws.bottom_min) / (lws.bottom_max - lws.bottom_min) * 100::numeric,
2) AS round
FROM unnest(dati1_v.lw_bottom_array) lw(lw))) AS lw_bottom_array
FROM dati1_v,
lw_settings lws
WHERE lws.id = 1
GROUP BY dati1_v.id_stazione, to_char(dati1_v.data_ora, 'YYYY-MM-DD HH24:00:00'::text), lws.top_min, lws.top_max,
lws.bottom_min, lws.bottom_max
ORDER BY dati1_v.id_stazione, to_char(dati1_v.data_ora, 'YYYY-MM-DD HH24:00:00'::text)
in particular, my tries were related to this specific block:
array_cat(dati1_v.lw_top_array) AS lw_top_array_tot,
-- array_agg((select lw_top_array from unnest(dati1_v.lw_top_array))) AS lw_top_array_tot,
-- array_agg(array_to_string(dati1_v.lw_top_array, ',')) AS lw_top_array_tot
Thanks
For me in similar case helped UNNEST in subquery and ARRAY_AGG of unnnested
SELECT
ARRAY_AGG(
DISTINCT lw_top
) as lw_top_array
FROM (
SELECT
UNNEST(lw_top_array) AS lw_top
FROM
dati1_v
) as tmp;
for me helped next query
SELECT
my_table.key,
array_agg(_unnested.item) as array_coll
from my_table
left join LATERAL (SELECT unnest(my_table.array_coll) as item) _unnested ON TRUE
GROUP by my_table.key
In PostgreSQL, the Group_concat function is not available but you can get similar result as string_agg and array_to_string.
string_agg(array_to_string(file_ids, ','), ',') filter ( where file_ids notnull ) AS file_ids_str
array_to_string and array_to_string works in next way
array_to_string([1, 2, 456], ',') => '1,2,456'
string_agg(['a', 'ab'], ',') => 'a,ab'
the only problem is that result is string with ',' as separator
I'm trying to use Npgsql and/or Dapper to query a table and I keep running into Npgsql.PostgresException 42601: syntax error at or near "$1".
Here is what I've got trying it with NpgsqlCommand:
using (var conn = new NpgsqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["postgres"].ConnectionString))
{
conn.Open();
using (NpgsqlCommand command = new NpgsqlCommand("select * from Logs.Logs where Log_Date > current_date - interval #days day;", conn))
{
command.Parameters.AddWithValue("#days", days);
var reader = command.ExecuteReader();
I've also tried it with Dapper(my preferred method) with:
using (var conn = new NpgsqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["postgres"].ConnectionString))
{
conn.Open();
var logs = conn.Query<Log>("select * from Logs.Logs where Log_Date > current_date - interval #days day;", new {days = days});
Either way I get the same Npgsql.PostgresException 42601: syntax error at or near "$1" error. The Statement in the Exception shows: select * from Logs.Logs where Log_Date > current_date - interval $1 day
Note, if I do the following it works fine, but it's not properly parameterized:
var logs = conn.Query<Log>("select * from Logs.Logs where Log_Date > current_date - interval '" + days + "' day;");
What am I doing wrong? I very much appreciate any feedback. Thank you.
PostgreSQL doesn't allow you to stick a parameter anywhere in a query. What you want can be achieved with the following:
var command = new NpgsqlCommand("select * from Logs.Logs where Log_Date > current_date - #days", conn))
command.Parameters.AddWithValue("#days", TimeSpan.FromDays(days));
This way you're passing the interval directly from Npgsql to PostgreSQL, rather than a part of the expression designed to create that interval.
i got this error using DapperExtensions
adding
DapperExtensions.DapperExtensions.SqlDialect = new PostgreSqlDialect();
DapperAsyncExtensions.SqlDialect = new PostgreSqlDialect();
before creating the connection fixed the issue
To subtract days from a date (assuming log_date is data type date), you can simplify:
"SELECT * FROM logs.logs WHERE log_date > CURRENT_DATE - #days;"
And provide #days as unquoted numeric literal (digits only) - which is taken to be an integer. This is even more efficient, since date - integer returns date, while date - interval returns timestamp.
The manual about interval input.
Okay I've confirmed this works explicitly with PHP.
$ php --version
PHP 5.6.16 (cli) (built: Dec 30 2015 15:09:50) (DEBUG)
<pdo version>
pdo_pgsql
PDO Driver for PostgreSQL enabled
PostgreSQL(libpq) Version 9.4.0
Module version 1.0.2
Revision $Id: fe003f8ab9041c47e97784d215c2488c4bda724d $
I would like to recreate the following SQL in PHP using PDO:
UPDATE relationships SET status = 4 WHERE created > NOW() - interval '2 seconds';
This script is working:
<?php
$db = new PDO('pgsql:dbname=db;host=localhost;user=stevetauber');
$stmt = $db->prepare("UPDATE relationships SET status = 4 WHERE created > NOW() - interval '?'");
$stmt->execute(array("2 seconds"));
Here it is with named placeholders:
<?php
$db = new PDO('pgsql:dbname=db;host=localhost;user=stevetauber');
$stmt = $db->prepare("UPDATE relationships SET status = 4 WHERE created > NOW() - interval ':blah'");
$stmt->execute(array(":blah" => "2 seconds"));
Which gives this error:
Warning: PDOStatement::execute(): SQLSTATE[HY093]: Invalid parameter number: :blah in ... line 5
Now according to PHP documentation,
Example #6 Invalid use of placeholder:
<?php
$stmt = $dbh->prepare("SELECT * FROM REGISTRY where name LIKE '%?%'");
$stmt->execute(array($_GET['name']));
// placeholder must be used in the place of the whole value
$stmt = $dbh->prepare("SELECT * FROM REGISTRY where name LIKE ?");
$stmt->execute(array("%$_GET[name]%"));
?>
Here is the updated code:
<?php
$db = new PDO('pgsql:dbname=db;host=localhost;user=stevetauber');
$stmt = $db->prepare("UPDATE relationships SET status = 4 WHERE created > NOW() - :blah");
$stmt->execute(array(":blah" => "interval '2 seconds'"));
Which yields these DB errors (no script errors):
ERROR: operator does not exist: timestamp with time zone > interval at character 51
HINT: No operator matches the given name and argument type(s). You might need to add explicit type casts.
STATEMENT: UPDATE relationships SET status = 4 WHERE created > NOW() - $1
PDO is doing something weird here though because:
# select NOW() - interval '2 seconds' as a , pg_typeof(NOW() - interval '2 seconds') as b;
a | b
-------------------------------+--------------------------
2015-12-30 18:02:20.956453+00 | timestamp with time zone
(1 row)
So how do I use named placeholders with PostgreSQL and interval?
Placeholders are for pure values, not for values decorated with units (or with anything else).
To express interval '2 seconds' in a placeholder, there are two options:
in the query, write :secs * interval '1 second'
and bind :secs to a number in php
or write: cast(:mystring as interval), and bind :mystring to the string '2 seconds'. It will be interpreted dynamically through the explicit cast.
When experimenting with the psql command line client to compare with the PDO driver, use the PREPARE and EXECUTE SQL statements with postgres native $N placeholders, as opposed to having the parameters values already written literally in the query. This will match what the PHP driver is essentially doing when PDO::ATTR_EMULATE_PREPARES is set to false.
In the last part of you question, when trying this in psql (your query, just simplified to not need a table):
select now() > now() - interval '2 seconds';
it does work and returns 't' (true).
But if you tried that:
prepare p as select now() > now() - $1;
if would fail with
ERROR: operator does not exist: timestamp with time zone > interval
which is the same error as with PDO's prepare/execute.
On the other hand, this does work:
=> prepare p as select now() > now() - interval '1 second'*$1;
PREPARE
=> execute p(2);
?column?
----------
t
I'm using NHibernate with Mapping by Code and I have a property that is created by this formula.
Property(x => x.IsInOverdue,
mapper => mapper
.Formula("(SELECT (state_ <> 3 AND invoice_uniqueAlias.duedate_ < NOW()) " +
" FROM _invoice AS invoice_uniqueAlias "+
" WHERE invoice_uniqueAlias.invoice_id = issuedinvoice_key)"));
It works perfectly, this sql is inserted as subselect in all queries...
But I would need to add 1 day to invoice_uniqueAlias.duedate_ value. We are using PostgreSQL where the syntax for it is: invoice_uniqueAlias.duedate_ + interval '1 day'
But when I put it in mapper.Formula, NHibernate thinks that interval is a name of column and in all queries tries to add table prefix before interval keyword. The generated SQL then looks like:
... (SELECT (issuedinvo0_.state_ <> 3
AND (invoice_uniqueAlias.duedate_ + (issuedinvo0_.interval '1 day')) < NOW()) ...
I tried to put interval keyword in [, `, put statement interval + '1 day' to brackets, but it didn't help. Any suggestions how to handle it correctly in NHibernate or how it is possible to write it in Postgres without using + interval syntax?
In case, we need NHibernate to treat some words (key words) as part of the underlying DB engine dialect, we have to just extend it.
One way would be the create custom dialect:
public class CustomPostgreDialect : PostgreSQL82Dialect
{
public CustomPostgreDialect()
{
RegisterKeyword("interval");
}
}
And now just use it:
<property name="dialect">My.Namespace.CustomPostgreDialect,My.Data</property>
Some similar issue - Using SQL CONVERT function through nHibernate Criterion (with the similar solution in this answer)