I create one sequence in postgres and fire one query which is mentioned below
SELECT M_PRODUCTSEQ.NEXTVAL from DUAL;
but it gives me the below error:
ERROR: relation "dual" does not exist.
Kindly help me out. How can i made the relation with dual?
PostgreSQL does NOT support the from DUAL syntax. It does however make the from portion of a query like this optional, so getting the next value (nextval) of a sequence you would do something like this:
SELECT nextval('m_productseq');
Related
I'm writing a Java application to automatically build and run SQL queries. For many tables my code works fine but on a certain table it gets stuck by throwing the following exception:
Exception in thread "main" org.postgresql.util.PSQLException: ERROR: column "continent" does not exist
Hint: Perhaps you meant to reference the column "countries.Continent".
Position: 8
The query that has been run is the following:
SELECT Continent
FROM network.countries
WHERE Continent IS NOT NULL
AND Continent <> ''
LIMIT 5
This essentially returns 5 non-empty values from the column.
I don't understand why I'm getting the "column does not exist" error when it clearly does in pgAdmin 4. I can see that there is a schema with the name Network which contains the table countries and that table has a column called Continent just as expected.
Since all column, schema and table names are retrieved by the application itself I don't think there has been a spelling or semantical error so why does PostgreSQL cause problems regardless? Running the query in pgAdmin4 nor using the suggested countries.Continent is working.
My PostgreSQL version is the newest as of now:
$ psql --version
psql (PostgreSQL) 9.6.1
How can I successfully run the query?
Try to take it into double quotes - like "Continent" in the query:
SELECT "Continent"
FROM network.countries
...
In working with SQLAlchemy environment, i have got this error with the SQL like this,
db.session.execute(
text('SELECT name,type,ST_Area(geom) FROM buildings WHERE type == "plaza" '))
ERROR: column "plaza" does not exist
Well, i changed == by = , Error still persists, then i interchanged the quotes, like follows. It worked. Weird!
....
text("SELECT name,type,ST_Area(geom) FROM buildings WHERE type = 'plaza' "))
This problem occurs in postgres because the table name is not tablename instead it is "tablename".
for eg.
If it shows user as table name,
than table name is "user".
See this:
Such an error can appear when you add a space in the name of a column by mistake (for example "users ").
QUICK FIX (TRICK)
If you have recently added a field which you have already deleted before and now trying to add the same field back then let me share you this simple trick! i did this and the problem was gone!!
so, now just delete the migration folder entirely on the app,then instead of adding that field you need to now add a field but with the name of which you have never declared on this app before, example if you are trying to add title field then create it by the name of heading and now do the migration process separately on the app and runserver, now go to admin page and look for that model and delete all the objects and come to models back and rename the field that you recently made and name it to which you were wishing it with earlier and do the migrations again and now your problem must have been gone!!
this occurs when the objects are there in the db but you added a field which wasn't there when the earlier objs were made, so by this we can delete those objs and make fresh ones again!
I got the same error when I do PIVOT in RedShift.
My code is similar to
SELECT *
INTO output_table
FROM (
SELECT name, year_month, sales
FROM input_table
)
PIVOT
(
SUM(sales)
FOR year_month IN ('nov_2020', 'dec_2020', 'jan_2021', 'feb_2021', 'mar_2021', 'apr_2021', 'may_2021', 'jun_2021', 'jul_2021', 'aug_2021',
'sep_2021', 'oct_2021', 'nov_2021', 'dec_2021', 'jan_2022', 'feb_2022', 'mar_2022', 'apr_2022', 'may_2022', 'jun_2022',
'jul_2022', 'aug_2022', 'sep_2022', 'oct_2022', 'nov_2022')
)
I tried year_month without any quote (got the error), year_month with double quote (got the error), and finally year_month with single quote (it works this time). This may help if someone in the same situation like my example.
I'm writing a Java application to automatically build and run SQL queries. For many tables my code works fine but on a certain table it gets stuck by throwing the following exception:
Exception in thread "main" org.postgresql.util.PSQLException: ERROR: column "continent" does not exist
Hint: Perhaps you meant to reference the column "countries.Continent".
Position: 8
The query that has been run is the following:
SELECT Continent
FROM network.countries
WHERE Continent IS NOT NULL
AND Continent <> ''
LIMIT 5
This essentially returns 5 non-empty values from the column.
I don't understand why I'm getting the "column does not exist" error when it clearly does in pgAdmin 4. I can see that there is a schema with the name Network which contains the table countries and that table has a column called Continent just as expected.
Since all column, schema and table names are retrieved by the application itself I don't think there has been a spelling or semantical error so why does PostgreSQL cause problems regardless? Running the query in pgAdmin4 nor using the suggested countries.Continent is working.
My PostgreSQL version is the newest as of now:
$ psql --version
psql (PostgreSQL) 9.6.1
How can I successfully run the query?
Try to take it into double quotes - like "Continent" in the query:
SELECT "Continent"
FROM network.countries
...
In working with SQLAlchemy environment, i have got this error with the SQL like this,
db.session.execute(
text('SELECT name,type,ST_Area(geom) FROM buildings WHERE type == "plaza" '))
ERROR: column "plaza" does not exist
Well, i changed == by = , Error still persists, then i interchanged the quotes, like follows. It worked. Weird!
....
text("SELECT name,type,ST_Area(geom) FROM buildings WHERE type = 'plaza' "))
This problem occurs in postgres because the table name is not tablename instead it is "tablename".
for eg.
If it shows user as table name,
than table name is "user".
See this:
Such an error can appear when you add a space in the name of a column by mistake (for example "users ").
QUICK FIX (TRICK)
If you have recently added a field which you have already deleted before and now trying to add the same field back then let me share you this simple trick! i did this and the problem was gone!!
so, now just delete the migration folder entirely on the app,then instead of adding that field you need to now add a field but with the name of which you have never declared on this app before, example if you are trying to add title field then create it by the name of heading and now do the migration process separately on the app and runserver, now go to admin page and look for that model and delete all the objects and come to models back and rename the field that you recently made and name it to which you were wishing it with earlier and do the migrations again and now your problem must have been gone!!
this occurs when the objects are there in the db but you added a field which wasn't there when the earlier objs were made, so by this we can delete those objs and make fresh ones again!
I got the same error when I do PIVOT in RedShift.
My code is similar to
SELECT *
INTO output_table
FROM (
SELECT name, year_month, sales
FROM input_table
)
PIVOT
(
SUM(sales)
FOR year_month IN ('nov_2020', 'dec_2020', 'jan_2021', 'feb_2021', 'mar_2021', 'apr_2021', 'may_2021', 'jun_2021', 'jul_2021', 'aug_2021',
'sep_2021', 'oct_2021', 'nov_2021', 'dec_2021', 'jan_2022', 'feb_2022', 'mar_2022', 'apr_2022', 'may_2022', 'jun_2022',
'jul_2022', 'aug_2022', 'sep_2022', 'oct_2022', 'nov_2022')
)
I tried year_month without any quote (got the error), year_month with double quote (got the error), and finally year_month with single quote (it works this time). This may help if someone in the same situation like my example.
I'm using Enterprise Postgres 9.5 with Oracle Compatibility. I have a problem with the EXECUTE IMMEDIATE command.
Say I have a table with few columns and one of them can accept NULLs. If I do
EXECUTE IMMEDIATE 'select null_col from '||table_name||' where col1=10' into x;
It sends the value to x, if null_col returns any.
When I given the condition col1=19, where 19 is not present in the table, then I get the error like this.
query returned no rows
and my execution stops. So how can I handle that. Oracle doesn't given any error for such statements, whereas EDB does. Please help.
I didn't find any EDB tags, so please tag if you think this is inappropriate question here. Thanks for understanding.
I'm trying to make an insert into postgres 8.4.13
insert into my_table (id, hour_memo) values (1,'17:30:00.000000 +01:00:00');
hour_memo is 'reltime datatype'
During the execution of the insert task i have this trouble:
ERROR: invalid input syntax for type reltime: "17:30:00.000000 +01:00:00"
I have absolutely no idea on how to do this?
The answer is that reltime doesn't support time zones, so the "+01..." thing is breaking it. Still - using reltime type is bad idea, and should be replaced by some normal type.
I have a PostGIS query where I really need to have nested queries inside PostGIS function calls:
UPDATE raw.geocoding
SET the_geom = ST_Centroid(
ST_Collect(
SELECT the_geom
FROM raw.geocoding
WHERE hash = ((E'0101000020090C000081610F9CC5DC3341EE672E6E723B3241')::varchar),
SELECT the_geom
FROM raw.geocoding
WHERE hash = ((E'0101000020090C00002CF887E0C5DC3341C9E5B2DF2A383241')::varchar)
)
)
WHERE hash = ((E'3e638a27c6c38f05026252f4a0b57b2e')::varchar)
Unfortunately, this doesn't work. I get a syntax error at the beginning of the nested query:
ERROR: syntax error at or near "SELECT"
LINE 4: SELECT the_geom
^
********** Error **********
ERROR: syntax error at or near "SELECT"
SQL state: 42601
Character: 86
Looks like I cannot have a nested query as a PostGIS function parameter?
I've perused through the PostGIS documentation and cannot find any clear guidance for dealing with this.
It appears Postgres has a way of doing variables in pgSQL, but it's unclear to me how this would be pulled off in a standard query. This is a query that will be run tens or hundreds of thousands of times from a C# program. That aside, I could do a pgSQL stored procedure if required; just wanted to make sure there wasn't a simpler alternative first.
In case you were wondering, the query looks messy because it's the result of a npgsql-generated parameterized query. I think it's fair to say that npgsql is being extra-cautious with redundant typing and escaping.
I am running PostGIS 2.0.1, Postgres 9.1.5, and npgsql 2.0.12.
It sounds like you want a scalar subquery, an expression written like (SELECT ....) (note enclosing parentheses) that contains a query returning either zero rows (NULL result) or one field from one row.
You were most of the way there, you just needed the parens:
UPDATE raw.geocoding
SET the_geom = ST_Centroid(
ST_Collect(
(SELECT the_geom
FROM raw.geocoding
WHERE hash = ((E'0101000020090C000081610F9CC5DC3341EE672E6E723B3241')::varchar)),
(SELECT the_geom
FROM raw.geocoding
WHERE hash = ((E'0101000020090C00002CF887E0C5DC3341C9E5B2DF2A383241')::varchar))
)
)
WHERE hash = ((E'3e638a27c6c38f05026252f4a0b57b2e')::varchar)
Note that subqueries can be used in other places too - table returning subqueries can appear in FROM, for example. The PostgreSQL manual teaches about all this, and is well worth a cover-to-cover read.
If you're doing a lot of these updates, you may find it more efficient to formulate the UPDATE as a join using the PostgreSQL extension UPDATE ... FROM ... WHERE rather than running lots of individual UPDATEs over and over. I just wanted to raise the possibility. See from-list in UPDATE