I am trying to select a particular value in the OSM polygon data using DB Manager in QGIS that is connected to the PostGIS database. When I type
SELECT *
FROM planet_osm_polygon
WHERE landuse is not null
This SQL statement works. It gives me all the rows that has the landuse values.
However, if I replace landuse with natural (which is another column name) it gives me an error message. I used another column name for example, leisure. I get the query result.
I am not sure why I can't use natural column heading name. Any clue to solve this error will be appreciated.
natural is a reserved keyword, so you need to enclose it is double quotes:
SELECT * FROM osm_polygons WHERE "natural" is not null;
PS: the same is true if you have a semicolon in the column name:
SELECT * FROM osm_polygons WHERE "addr:housenumber" is not null;
Related
I'm trying to extract data from a bytea column which stores JSON data in Postgres 11.9 version.
However, the my code is throwing an error:
ERROR: invalid input syntax for type json
DETAIL: Token "" is invalid.
CONTEXT: JSON data, line 1: ...
Here is the sample data:
create table EMPLOYEE (PAYMENT bytea,NAME character varying);
insert into EMPLOYEE
values ('[{"totalCode":{"code":"EMPLOYER_TAXES"},"totalValue":{"amount":122.5,"currencyCode":"USD"}},{"totalCode":{"code":"OTHER_PAYMENTS"},"totalValue":{"amount":0.0,"currencyCode":"USD"}},{"totalCode":{"code":"GROSS_PAY"},"totalValue":{"amount":1000.0,"currencyCode":"USD"}},{"totalCode":{"code":"TOTAL_HOURS"},"totalValue":{"amount":40.0}}]'::bytea,'Tom')
;
Here is my query:
SELECT *
FROM EMPLOYEE left outer join lateral
jsonb_array_elements(PAYMENT::text::jsonb) element1 on true ;
Please help me in accessing data from this array. Data is always JSON in format.
There was a restriction to use bytea for this column.
You are making your life unnecessary hard by storing JSON values in a bytea column. Just because this is the recommended way in Oracle, doesn't mean this is a good choice for Postgres.
The correct solution is to change that column to jsonb. You will have to have a DBMS specific layer in your application anyway as the actual functions and operators you are using are very different.
Having said that, you can get away with this awful choice by using the convert_from() method:
select e.name, element1.*
from employee e
left join lateral jsonb_array_elements(convert_from(PAYMENT, 'UTF-8')::jsonb) element1 on true;
I also think you should change your INSERT statement to do an explicit conversion from text to bytea so that you can be sure the correct encoding is used:
insert into employee (payment, name)
values (convert_to('[{...}]', 'UTF-8'),'Tom');
But again: the only correct solution is to change that column to jsonb (or least json)
I have a trigger that takes a line, grabs its ST_StartPoint and ST_EndPoint and then grabs the nearest point to those endpoints, and assigns a node_id to a column. This Fiddle shows the trigger as well as some example data. When running this trigger, I am getting an error on QGIS stating the following:
Could not commit changes to layer pipes
Errors: ERROR: 1 feature(s) not added.
Provider errors:
PostGIS error while adding features: ERROR: Operation on mixed SRID geometries
CONTEXT: SQL statement "SELECT
j.node_id,
i.node_id
FROM ST_Dump(ST_SetSRID(NEW.geom,2346)) dump_line,
LATERAL (SELECT s.node_id,(ST_SetSRID(s.geom,2346))
FROM structures s
ORDER BY ST_EndPoint((dump_line).geom)<->s.geom
LIMIT 1) j (node_id,geom_closest_downstream),
LATERAL (SELECT s.node_id,(ST_SetSRID(s.geom,2346))
FROM structures s
ORDER BY ST_StartPoint((dump_line).geom)<->s.geom
LIMIT 1) i (node_id,geom_closest_upstream)"
PL/pgSQL function sewers."Up_Str"() line 3 at SQL statement
I have attempted to resolve the issue by editing the trigger to this but this has not fixed the problem. Any ideas would be greatly appreciated.
The line ORDER BY ST_EndPoint((dump_line).geom)<->s.geom (and the similar one for the start point) is likely the faulty one.
You could, again, declare the CRS of s.geom. Note that by doing this any spatial index on structures would not be used, it would have to be created on ST_SetSRID(geom,2346)
The clean way would be to set the CRS at the column level on the structures table
alter table structures alter column geom TYPE geometry(point,2346) using st_setSRID(geom,2346);
Query:
Select x classifier from tabx x
returns rows with one column named 'classifier' with list of values from the row.
Does anybody know where such features are documented? Is it the only usage of the keyword? I tried to google it but I've found only list of postgresql reserved keywords without explanation.
Example
It works like String_agg with ',' delimiter, but for a row.
It's called a column alias.
For columns it's documented here and for tables it's documented here
The name of the alias is irrelevant and bears no special meaning (including the word "classifier"). It just has to be a valid SQL identifier. Using an alias won't change anything in the resulting data.
If you use the (optional) AS keyword, it might be a bit more obvious:
select some_column as something_else
from some_table as another_name;
The reference x refers to the table alias specified in the FROM clause and refers to the complete row/record. It's not the column alias ("classifier") that does this, it's the reference to the table.
This behaviour is documented here in the manual
Edit after a new query was shown.
select a classifier, a.classifier
from t_attribute a;
The part a classifier still gives an alias to the record column (as explained above). a.classifier simply accesses a column from the table t_attribute.
It could also have been written as:
select a as the_complete_row, a.classifier as classifier
from t_attribute a;
We are seeing issue in table value which are populated from DB2 (source) to Postgres (Target).
I have including here all the job details for each component.
Based on the above approach and once the data has been populated, when we run the below query in the Postgres DB.
SELECT * FROM VMRCTTA1.VMRRCUST_SUMM where cust_gssn_cd='XY03666699' ;
SELECT * FROM VMRCTTA1.VMRRCUST_SUMM where cust_cntry_cd='847' ;
There will be no records were returned however, when we run the same query with Trim as below it works.
SELECT * FROM VMRCTTA1.VMRRCUST_SUMM where trim(cust_gssn_cd)='XY03666699' ;
SELECT * FROM VMRCTTA1.VMRRCUST_SUMM where trim(cust_cntry_cd)='847' ;
Below are the ways we have tried to overcome this but no luck.
Used tmap between source and target component.
Used trim in source component under Advanced setting.
Change the datatype in Postgres DB of cust_cntry_cd from char(5) to Character varying, this will allow value without any length restriction.
Please suggest what is missing as we have this issue in almost all the table where we have character/varchar columns.
We are using TOS.
The data type is probably character(5) in DB2.
That means that the trailing spaces are part of the column and will be migrated. You have to compare with
cust_cntry_cd = '847 '
or cast the right argument to character(5):
cust_cntry_cd = CAST ('847' AS character(5))
Maybe you could delete all spaces in the advanced settings of the tDB2Input component.
Like the screen :
I wonder if someone could have an idea what is going wrong with this simple query on a hstore column in PostgreSQL 9.2
The queries are runned in pgAdmin
select attributeValue->"CODE_MUN" from shapefile_feature
returns: « attributevalue » column does not exists
when doing:
select * from shapefile_feature;
all the columns are returned including attributeValue, the hstore column
what is the problem?
PostgreSQL distinguish between "identifiers" and 'literal'. Identifiers are schema, table, column's, .. names, literals are others. A attribute in hstore are not SQL identifiers. So you have to pass their names as literals. Operator "->" is only shortcut for function "fetchval(hstore, text)" with possibility be indexed.
select attributeValue->'CODE_MUN' from shapefile_feature
is internally transformed to (don't do this transformation by self!)
select fetchval(attributeValue, 'CODE_MUN') from shapefile_feature
on buggy example in transformed form, you can better understand to error message:
select fetchval(attributeValue, "CODE_MUN") from shapefile_feature
PostgreSQL tries to find column "CODE_MUN" in shapefile_feature, bacause used double quotes means identifiers (in case sensitive notation).