I develop a desktop application on PYQT5 with integration of posgtresql. I stumbled over the situation that the table does not display the values:
source code:
def createTable(self):
self.tableWidget = QTableWidget()
conn = psycopg2.connect('host=localhost port=5432 dbname=postgres user=postgres password=12345678')
cursor = conn.cursor()
query = cursor.execute("SELECT * FROM wave_params")
result = cursor.fetchall()
for i in result:
print(i)
rows = len(result)
columns = len(result[0])
self.tableWidget.setColumnCount(columns)
self.tableWidget.setRowCount(rows)
index = 0
while query != None:
self.tableWidget.setItem(index,0, QTableWidgetItem(query.result[0]))
# self.tableWidget.setItem(index, 1, QTableWidgetItem(str(query.value(1))))
# self.tableWidget.setItem(index, 2, QTableWidgetItem(str(query.value(2))))
index = index + 1
# table selection change
self.tableWidget.doubleClicked.connect(self.on_click)
#pyqtSlot()
def on_click(self):
print("\n")
for currentQTableWidgetItem in self.tableWidget.selectedItems():
print(currentQTableWidgetItem.row(), currentQTableWidgetItem.column(), currentQTableWidgetItem.text())
I can not understand. what is the problem?
Thanks!
the cursor object has no attribute result.
in your code result is a list of tuples containing the return value of cursor.fetchall() and query is the return value of cursor.execute(). cursor.execute() returns always None
(see documentation). You only need to loop over result, here 2 examples:
def createTable(self):
self.tableWidget = QTableWidget(self)
psycopg2.connect('host=localhost port=5432 dbname=postgres user=postgres password=12345678')
cursor = conn.cursor()
query = cursor.execute("SELECT * FROM ladestelle")
result = cursor.fetchall()
rows = len(result)
columns = len(result[0])
self.tableWidget.setColumnCount(columns)
self.tableWidget.setRowCount(rows)
for i, r in enumerate(result):
self.tableWidget.setItem(i, 0, QTableWidgetItem(r[0]))
self.tableWidget.setItem(i, 1, QTableWidgetItem(str(r[1])))
self.tableWidget.setItem(i, 2, QTableWidgetItem(str(r[2])))
'''
# or simpler
for r in range(rows):
for c in range(columns):
self.tableWidget.setItem(r, c, QTableWidgetItem(str(result[r][c])))
'''
self.tableWidget.doubleClicked.connect(self.on_click)
Related
I have a huge data in elastic search and i want to write a script to create a table corresponding to a particular index and transfer all the data to postgres.
Nevermind, I got my answer. What i did was to
create a connection with postgres and elastic search
create table in postgresql
store data in chunks of 10k in a list of dictionary.
transfer data from that list of dictionary in the postgresql and then empty the list for next iteration.
import psycopg2
from elasticsearch import Elasticsearch
from elasticsearch_dsl import Search
from collections import defaultdict
dict = defaultdict(list)
t_host = "localhost"
t_port = "9200"
t_dbname_ES = "companydatabase" #index
t_user = "elastic"
t_pw = "changeme"
client_ES = Elasticsearch([t_host],http_auth=(t_user, t_pw),port=t_port)
t_host = "localhost"
t_port = "5999"
t_dbname = "postgres"
t_user = "postgres"
t_pw = "postgres"
db_conn = psycopg2.connect(host=t_host, port=t_port, dbname=t_dbname, user=t_user, password=t_pw)
db_cursor = db_conn.cursor()
column_name_list = ["Address","Age","DateOfJoining","Designation","FirstName","Gender","Interests","LastName","MaritalStatus","Salary"]
column_type_list = ["text not null","integer","date","text","text","text","text","text","text","text","text","text","integer"]
table_name = 'sample_table2' #table name to insert data into
column_names = ', '.join(column_name_list)
column_types = ", ".join(column_type_list)
#table creation
create_table_query = "CREATE TABLE {} (".format(table_name)
for i in range(len(column_name_list)):
create_table_query += column_name_list[i]
create_table_query += " "
create_table_query += column_type_list[i]
if i != len(column_name_list) - 1:
create_table_query += ", "
create_table_query += ");"
try:
db_cursor.execute(create_table_query)
db_conn.commit()
except psycopg2.Error as e:
t_message = "Database error: " + e
#data insertion
s = Search(index=t_dbname_ES).using(client_ES).query("match_all")
total_documents = s.count() #total count of records in the index
count=0
for hit in s.scan(): #looping over all records one at a time
count+=1
total_documents -=1
for i in range(len(column_name_list)): #appending the data fethed from document in a list of dictionary.
dict[column_name_list[i]].append(hit[column_name_list[i]])
if count==10000 or total_documents==0: #appending data in postgres 10k records at a time
insert_query = "INSERT INTO "+table_name+" (" + column_names + ")"+" VALUES"
for i in range(min(10000,count)):
insert_query += "("
for j in range(len(column_name_list)):
if j!=0:
insert_query+=', '+ "'"+str(dict[column_name_list[j]][i])+"'"
else:
insert_query+="'"+str(dict[column_name_list[j]][i])+"'"
insert_query += "),"
insert_query= insert_query[:-1]
insert_query += ";"
for i in range(len(column_name_list)): #making the list empty for next iteration of 10k records
dict[column_name_list[i]]=[]
try:
db_cursor.execute(insert_query)
db_conn.commit()
count=0
except psycopg2.Error as e:
t_message = "Database error: " + e
db_cursor.close()
db_conn.close()
I am trying to update if exists or insert into if not exists in same table in DB2 (v 9.7).
I have one table "V_OPORNAC" (scheme is SQLDBA) which contains three columns with two primary keys: IDESTE (PK), IDEPOZ (PK), OPONAR
My case is, if data (OPONAR) where IDESTE = 123456 AND IDEPOZ = 0 not exits then insert new row, if exits then update (OPONAR). I have tried this:
MERGE INTO SQLDBA.V_OPONAROC AS O1
USING (SELECT IDESTE, IDEPOZ, OPONAR FROM SQLDBA.V_OPONAROC WHERE IDESTE = 123456 AND IDEPOZ = 0) AS O2
ON (O1.IDESTE = O2.IDESTE)
WHEN MATCHED THEN
UPDATE SET
OPONAR = 'test text'
WHEN NOT MATCHED THEN
INSERT
(IDESTE, IDEPOZ, OPONAR)
VALUES (123456, 0, 'test new text')
Executing code above I am getting this error:
Query 1 of 1, Rows read: 0, Elapsed time (seconds) - Total: 0,013, SQL query: 0,013, Reading results: 0
Query 1 of 1, Rows read: 3, Elapsed time (seconds) - Total: 0,002, SQL query: 0,001, Reading results: 0,001
Warning: DB2 SQL Warning: SQLCODE=100, SQLSTATE=02000, SQLERRMC=null, DRIVER=4.21.29
SQLState: 02000
ErrorCode: 100
I figured out, by using "SYSIBM.SYSDUMMY1"
MERGE INTO SQLDBA.V_OPONAROC AS O1
USING (SELECT 1 AS IDESTE, 2 AS IDEPOZ, 3 AS OPONAR FROM SYSIBM.SYSDUMMY1) AS O2
ON (O1.IDESTE = 123456 AND O1.IDEPOZ = 0)
WHEN MATCHED THEN
UPDATE SET
O1.OPONAR = 'test text'
WHEN NOT MATCHED THEN
INSERT
(O1.IDESTE, O1.IDEPOZ, O1.OPONAR)
VALUES (123456, 0, 'test new text')
I'm trying to pass a variable number of arguments to db.Query() in Go. I'm doing something like:
var values []interface{}
query := []string{"SELECT * FROM table"}
sep := "WHERE"
if ... {
values = append(values, something)
query = append(query, fmt.Sprintf(` %s field_a=$%d`, sep, len(values))
sep = "AND"
}
if ... {
values = append(values, something)
query = append(query, fmt.Sprintf(` %s field_b=$%d`, sep, len(values))
sep = "AND"
}
// Add an arbitrary number of conditional arguments...
rows, err := db.Query(strings.Join(query, " "), values...)
The query looks fine, and the values are all there, but I'm not getting anything back from the query. Some of the values are integers, some strings. When I manually try the exact same query (copy/paste) in psql, I substituting the actual values for $1, $2, etc, I get correct results. What am I missing?
Edit
Here's an example of what the final query (the result of strings.Join()) should look like:
SELECT
table1.field1, table1.field2, table1.field3,
table2.field4, table2.field6, table2.field6
FROM table1, table2
WHERE
table1.field2=$1 AND
table2.field3 IN ($2, $3)
When I try:
SELECT
table1.field1, table1.field2, table1.field3,
table2.field4, table2.field6, table2.field6
FROM table1, table2
WHERE
table1.field2='something' AND
table2.field3 IN (40, 50)
from psql, it works fine. When I call:
var values []interface{}
values = append(values, "something")
values = append(values, 40)
values = append(values, 50)
db.Query(`SELECT
table1.field1, table1.field2, table1.field3,
table2.field4, table2.field6, table2.field6
FROM table1, table2
WHERE
table1.field2=$1 AND
table2.field3 IN ($2, $3)`, values...)
from Go, I get a Rows object that returns false the first time rows.Next() is called, and a nil error.
I am trying to use postgresql in Python.The query is against a numeric field value in the where condition. The result set is not fetching and giving error ("psycopg2.ProgrammingError: no results to fetch").There are records in the database with agent_id (integer field) > 1.
import psycopg2
# Try to connect
try:
conn=psycopg2.connect("dbname='postgres' host ='localhost')
except:
print "Error connect to the database."
cur = conn.cursor()
agentid = 10000
try:
sql = 'SELECT * from agent where agent_id > %s::integer;'
data = agentid
cur.execute(sql,data)
except:
print "Select error"
rows = cur.fetchall()
print "\nRows: \n"`
for row in rows:``
print " ", row[9]
Perhaps try these things in your code:
conn=psycopg2.connect("dbname=postgres host=localhost user=user_here password=password_here port=port_num_here")
sql = 'SELECT * from agent where agent_id > %s;'
data = (agentid,) # A single element tuple.
then use
cur.execute(sql,data)
Also, I am confused here to what you want to do with this code
for row in rows:``
print " ", row[9]
Do you want to print each row in rows or just the 8th index of rows, from
rows = cur.fetchall()
If you wanted that index, you could
print rows[9]
My SQL query looks like this:
product = 'Huggies Little Movers Diaper Pants for Boys Size 5 (60 Count)'
retailer = 'Target'
query = """SELECT * FROM product_info WHERE product_name = %s AND retailer = %s""" % (product, retailer)
conn = psycopg2.connect("dbname='test1' user='postgres' host='localhost' password='123'")
cur = conn.cursor(cursor_factory = psycopg2.extras.RealDictCursor)
cur.execute(query)
When i execute that i get a error saying:
psycopg2.ProgrammingError: syntax error at or near "Basic"
I am not sure why my syntax is wrong
Your statement;
query = """SELECT * FROM product_info WHERE product_name = %s AND retailer = %s""" % (product, retailer)
...builds a complete string from the query and parameters without any quoting around your strings, which makes the entire string invalid SQL which fails at execute;
SELECT * FROM product_info
WHERE product_name = Huggies Little Movers Diaper Pants for Boys Size 5 (60 Count)
AND retailer = Target
What you're probably trying to do is parameterizing your query which is instead done in execute by passing the parameters in a tuple;
query = """SELECT * FROM product_info WHERE product_name = %s AND retailer = %s"""
...
cur.execute(query, (product, retailer))