I have this python3 code :
conn = psycopg2.connect( ... )
curr = conn.cursor()
curr.execute(code)
rows = curr.fetchall()
where 'code' has the select query statement
After executing this, 'rows' list will have lists of only the selected row values. How do I run 'curr.execute' in such a way that I also get the respective col headers too?
Meaning if I have say
Select col1, col2 from table Where some_condition;
I want my 'rows' list to have something like [['col1', 'col2'], [some_val_for_col1, some_val_for_col2] ....]. Any other ways of getting these col headers are also fine, but the select query in 'code' shouldn't change.
you have to execute 2 commands
curr.execute("Select * FROM people LIMIT 0")
colnames = [desc[0] for desc in curs.description]
curr.execute(code)
you can follow steps mentioned in https://kb.objectrocket.com/postgresql/get-the-column-names-from-a-postgresql-table-with-the-psycopg2-python-adapter-756
Related
I'm working in a bank so I had to adjust the column names and information in the query to fit the external web, so if there're any weird mistakes know it is somewhat fine.
I'm trying to use the CASE clause to display data from a different table, I know this is a workaround but due to certain circumstances I'm obligated to use it, plus it is becoming interesting to figure out if there's an actual solution.
The error I'm receiving for the following query is:
"ERROR [21000] [IBM][CLI Driver][DB2] SQL0811N The result of a scalar
fullselect, SELECT INTO statement, or VALUES INTO statement is more
than one row."
select bank_num, branch_num, account_num, client_id,
CASE
WHEN exists(
select *
from bank.services BS
where ACCS.client_id= BS.sifrur_lakoach
)
THEN (select username from bank.services BS where BS.client_id = ACCS.client_id)
ELSE 'NONE'
END username_new
from bank.accounts accs
where bank_num = 431 and branch_num = 170
EDIT:
AFAIK we're using DB2 v9.7:
DSN11015 - DB21085I Instance "DB2" uses "64" bits and DB2 code release "SQL09075" with
level identifier "08060107".
Informational tokens are "DB2 v9.7.500.702", "s111017", "IP23287", and Fix Pack "5".
Use listagg function to include all results.
select bank_num, branch_num, account_num, client_id,
CASE
WHEN exists(
select *
from bank.services BS
where ACCS.client_id= BS.sifrur_lakoach
)
THEN (select LISTAGG(username, ', ') from bank.services BS
where BS.client_id = ACCS.client_id)
ELSE 'NONE'
END username_new
from bank.accounts accs
where bank_num = 431 and branch_num = 170
I am trying to update data in Table: local.import_payments from Table: local.payments based on update and Inner Join queries. The query I used:
Update local.import_payments
Set local.import_payments.client_id = local.payments.payment_for_client__record_id,
local.import_payments.client_name = local.payments.payment_for_client__company_name,
local.import_payments.customer_id = local.payments.customer__record_id,
local.import_payments.customer_name = local.payment_from_customer,
local.import_payments.payment_id = local.payments.payment_id
From local.import_payments
Inner Join local.payments
Where local.payments.copy_to_imported_payments = 'true'
The client_id, client_name, customer_id, customer_name in the local.import_payments need to get updated with the values from the table local.payments based on the condition that the field copy_to_imported_payments is checked.
I am getting a syntax error while executing the query. I tried a couple of things, but they did not work. Can anyone look over the queries and let me know where the issue is
Try the following
UPDATE local.import_payments
Set local.import_payments.client_id =
local.payments.payment_for_client__record_id,
local.import_payments.client_name =
local.payments.payment_for_client__company_name,
local.import_payments.customer_id = local.payments.customer__record_id,
local.import_payments.customer_name = local.payment_from_customer,
local.import_payments.payment_id = local.payments.payment_id
FROM local.payments as lpay
WHERE lpay.<<field>> = local.import_payments.<<field>>
AND local.payments.copy_to_imported_payments = 'true'
You shouldn't to specify the schema/table for updated columns, only column names:
Do not include the table's name in the specification of a target column — for example, UPDATE table_name SET table_name.col = 1 is invalid.
from the doc
You shouldn't to use the updating table in the from clause except of the case of self-join.
You can to make your query shorter using "column-list syntax".
update local.import_payments as target
set (
client_id,
client_name,
customer_id,
customer_name,
payment_id) = (
source.payment_for_client__record_id,
source.payment_for_client__company_name,
source.customer__record_id,
source.payment_from_customer,
source.payment_id)
from local.payments as source
where
<join condition> and
source.copy_to_imported_payments = 'true'
I have this issue where if there is no record in copy_on_write.id then the UPDATE listings SET images = (SELECT images FROM new_vals) runs and wipes out listings.images with nothing.
So, I am trying to use a condition to only run the UPDATE listings if copy_on_write.images exist.
right now I get:
psql:queries/copy-to-source.sh:20: ERROR: syntax error at or near "CASE"
LINE 10: CASE WHEN images <>
WITH
new_vals AS (
SELECT *
FROM copy_on_write
WHERE copy_on_write.posted_by = 102550922::text
AND copy_on_write.id = 4
),
updates AS (
SELECT images FROM new_vals,
CASE WHEN images <> ''
THEN UPDATE listings SET images = (SELECT images FROM new_vals)
END
)
SELECT internal_id FROM new_vals
You can use updates CTE like this:
...
updates AS (
UPDATE listings SET
images = new_vals.images
FROM new_vals
WHERE new_vals.images <> ''
)
....
Note, that:
Your new_vals CTE should always return maximum one record, otherwise this won't works correct.
Also this not updates listings table, if new_vals returns images column, but it is empty string (or null). If in such cases you need run update anyway, then remove WHERE new_vals.images <> '' at all.
And also, this statement will update all listings.images records. Do you really want this?
I have imported one shapefile named tc_bf25 using qgis, and the following is my python script typed in pyscripter,
import sys
import psycopg2
conn = psycopg2.connect("dbname = 'routing_template' user = 'postgres' host = 'localhost' password = '****'")
cur = conn.cursor()
query = """
ALTER TABLE tc_bf25 ADD COLUMN source integer;
ALTER TABLE tc_bf25 ADD COLUMN target integer;
SELECT assign_vertex_id('tc_bf25', 0.0001, 'the_geom', 'gid')
;"""
cur.execute(query)
query = """
CREATE OR REPLACE VIEW tc_bf25_ext AS
SELECT *, startpoint(the_geom), endpoint(the_geom)
FROM tc_bf25
;"""
cur.execute(query)
query = """
CREATE TABLE node1 AS
SELECT row_number() OVER (ORDER BY foo.p)::integer AS id,
foo.p AS the_geom
FROM (
SELECT DISTINCT tc_bf25_ext.startpoint AS p FROM tc_bf25_ext
UNION
SELECT DISTINCT tc_bf25_ext.endpoint AS p FROM tc_bf25_ext
) foo
GROUP BY foo.p
;"""
cur.execute(query)
query = """
CREATE TABLE network1 AS
SELECT a.*, b.id as start_id, c.id as end_id
FROM tc_bf25_ext AS a
JOIN node AS b ON a.startpoint = b.the_geom
JOIN node AS c ON a.endpoint = c.the_geom
;"""
cur.execute(query)
query = """
ALTER TABLE network1 ADD COLUMN shape_leng double precision;
UPDATE network1 SET shape_leng = length(the_geom)
;"""
cur.execute(query)
I got the error at the second cur.execute(query),
But I go to pgAdmin to check result, even though no error occurs, the first cur.execute(query) didn't add new columns in my table.
What mistake did I make？ And how to fix it？
I am working with postgresql 8.4, python 2.7.6 under Windows 8.1 x64.
When using psycopg2, autocommit is set to False by default. The first two statements both refer to table tc_bf25, but the first statement makes an uncommitted change to the table. So try running conn.commit() between statements to see if this resolves the issue
You should run each statement individually. Do not combine multiple statements into a semicolon separated series and run them all at one. It makes error handling and fetching of results much harder.
If you still have the problem once you've made that change, show the exact statement you're having the problem with.
Just to add to #Talvalin you can enable auto-commit by adding
psycopg2.connect("dbname='mydb',user='postgres',host ='localhost',password = '****'")
conn.autocommit = True
after you connect to your database using psycopg2
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