I have a table t that contains a column year. The following command returns
class t.Year
ans =
char
This is not just for the column year but for all columns in the table.
I need to convert the table to a cellstr so that I can do str2num function on it. I am unable to convert all the columns and rows to string type. I also need to remove '' from the column names when I do table2cell. After table2cell I need to convert to cellstr and I am unable to do so since all the values in the table(columns) are char.
Related
I have a column(field1) defined as varchar in snowflake. It is storing both string and numbers(ex values: US15876, 1.106336965E9). How can I convert the numeric values to display something like 1106336965, without losing the columns that is storing string values or null values. I am trying try_to_numeric(field1), but this is eliminating the record with string values and showing them as null. Any help is appreciated.
So try_to_number is the way to have numbers, and nulls for non-number without errors. But if you want to keep the strings, you actually have to convert your newly create number, back to text (or variant), otherwise it cannot be in the same column, so nothing is gained:
select column1
,try_to_number(column1) as_num
,nvl(as_num::text, column1) as why_not_both
from values
('US15876'),
('1.106336965E9'),
('1.106336965'),
('1106336965');
COLUMN1
AS_NUM
WHY_NOT_BOTH
US15876
null
US15876
1106336965
1,106,336,965
1106336965
1.106336965
1
1
1106336965
1,106,336,965
1106336965
How can I concatenate a string inside of a concatenated jsonb object in postgresql? In other words, I am using the JSONb concatenate operator as well as the text concatenate operator in the same query and running into trouble.
Or... if there is a totally different query I should be executing, I'd appreciate hearing suggestions. The goal is to update a row containing a jsonb column. We don't want to overwrite existing key value pairs in the jsonb column that are not provided in the query and we also want to update multiple rows at once.
My query:
update contacts as c set data = data || '{"geomatch": "MATCH","latitude":'||v.latitude||'}'
from (values (16247746,40.814140),
(16247747,20.900840),
(16247748,20.890570)) as v(contact_id,latitude) where c.contact_id = v.contact_id
The Error:
ERROR: invalid input syntax for type json
LINE 85: update contacts as c set data = data || '{"geomatch": "MATCH...
^
DETAIL: The input string ended unexpectedly.
CONTEXT: JSON data, line 1: {"geomatch": "MATCH","latitude":
SQL state: 22P02
Character: 4573
You might be looking for
SET data = data || ('{"geomatch": "MATCH","latitude":'||v.latitude||'}')::jsonb
-- ^^ jsonb ^^ text ^^ text
but that's not how one should build JSON objects - that v.latitude might not be a valid JSON literal, or even contain some injection like "", "otherKey": "oops". (Admittedly, in your example you control the values, and they're numbers so it might be fine, but it's still a bad practice). Instead, use jsonb_build_object:
SET data = data || jsonb_build_object('geomatch', 'MATCH', 'latitude', v.latitude)
There are two problems. The first is operator precedence preventing your concatenation of a jsonb object to what is read a text object. The second is that the concatenation of text pieces requires a cast to jsonb.
This should work:
update contacts as c
set data = data || ('{"geomatch": "MATCH","latitude":'||v.latitude||'}')::jsonb
from (values (16247746,40.814140),
(16247747,20.900840),
(16247748,20.890570)) as v(contact_id,latitude)
where c.contact_id = v.contact_id
;
I have two tables. I want to update the emodnet_code column values of the table named 2018_01 based on the column emodnet_type of another table named shiptype_emodnet and using the matching of values of two other columns: column aisshiptype from 2018_01 table and column aisshiptype from shyptype_emodnet table. Query returned successfully but 0 rows affected:
UPDATE "2018_01"
SET emodnet_code = shiptype_emodnet.emodnet_type
FROM "shiptype_emodnet"
WHERE '2018_01.aisshiptype' = 'shiptype_emodnet.aisshiptype';
You are comparing string constants in your WHERE clause, not columns. So your where clause:
WHERE '2018_01.aisshiptype' = 'shiptype_emodnet.aisshiptype';
is always false, because the string literal '2018_01.aisshiptype' is never the same as the string literal 'shiptype_emodnet.aisshiptype'. So your where condition is essentially the same as:
where false
Identifiers need to be quoted with double quotes ("). Single quotes (') are only for string literals.
UPDATE "2018_01"
SET emodnet_code = shiptype_emodnet.emodnet_type
FROM "shiptype_emodnet"
WHERE "2018_01".aisshiptype = shiptype_emodnet.aisshiptype;
And you only need the double quotes for columns or tables that use names that are illegal in SQL or were created using double quotes and mixed case.
Can you try:
UPDATE "2018_01" t
SET t.emodnet_code = (SELECT shiptype_emodnet.emodnet_type
FROM shiptype_emodnet
WHERE t.aisshiptype = shiptype_emodnet.aisshiptype
Limit 1);
You should add limit 1 for update each row
I have the below table "dates" , it has a sym column with symbols and a d column with list of strings and would like to save it into a regular CSV file. Couldn't find a good way to do it. Any suggestions?
q)dates
sym d
----------------------------------------------------------------------------
6AH0 "1970.03.16" "1980.03.17" "1990.03.19" "2010.03.15"
6AH6 "1976.03.15" "1986.03.17" "1996.03.18" "2016.03.14"
6AH7 "1977.03.14" "1987.03.16" "1997.03.17" "2017.03.13"
6AH8 "1978.03.13" "1988.03.14" "1998.03.16" "2018.03.19"
6AH9 "1979.03.19" "1989.03.13" "1999.03.15" "2019.03.18"
When I try to do the regular save the below error happens:
q)save `:dates.csv
k){$[t&77>t:#y;$y;x;-14!'y;y]}
'type
q))
The internal table->csv conversion function within Kdb+ is not able to handle nested lists in columns. The d column in your table is a list of list of chars. However, the conversion function is able to handle a simply nested column (depth of 1).
Therefore, you can convert the d column to a list of chars and then save to CSV using the internal function:
/ generate a table of dummy data
q)show dates:flip `sym`d!(`6AH0`6AH6`6AH7;string (3;0N)#12?.z.d)
sym d
--------------------------------------------------------
6AH0 "2008.02.04" "2015.01.02" "2003.07.05" "2005.02.25"
6AH6 "2012.10.25" "2008.08.28" "2017.01.25" "2007.12.27"
6AH7 "2004.02.01" "2005.06.06" "2013.02.11" "2010.12.20"
/ convert 'd' column to simple list - the (" " sv') is the conversion func here
q)#[`dates;`d;" " sv']
`dates
/ review what was done
q)show dates
sym d
--------------------------------------------------
6AH0 "2008.02.04 2015.01.02 2003.07.05 2005.02.25"
6AH6 "2012.10.25 2008.08.28 2017.01.25 2007.12.27"
6AH7 "2004.02.01 2005.06.06 2013.02.11 2010.12.20"
/ save to csv
q)save `:dates.csv
`:dates.csv
/ review saved csv
q)\cat dates.csv
"sym,d"
"6AH0,2008.02.04 2015.01.02 2003.07.05 2005.02.25"
"6AH6,2012.10.25 2008.08.28 2017.01.25 2007.12.27"
"6AH7,2004.02.01 2005.06.06 2013.02.11 2010.12.20"
As per the csv specification, you'll want to flatten the list out and separate each with a comma and double quote the list.
'save' is limited in that the file must be named the same as the global variable you are saving.
If I was tasked with your question I'd do it like so;
`:myFileNamedWhatever.csv 0: csv 0: select sym,csv sv'd from dates
Explanation;
csv 0: table /csv is a variable, literally defined as "," - its good for readability. csv 0: table converts the table to a comma separated list of strings
`:file 0: listOfStrings /this takes a LIST of strings and pushes them to the file handle. Each element of the list is a new line in the file
I'd prefer this approach as it is general and allows the saving of various types. You can use it within a function etc..
At a later date I decided that I wanted it saved as a pipe (or anything) separated file;
`:myNewFile.psv 0: "|" 0: select sym,"|"sv'd from table
I have a day column and a month column and would like to concatenate the year to it and store it in CHARARRAY format with the hyphens.
so I have: month:CHARARRAY, day:CHARARRAY
Meaning, for example, if the day column contains '03' and the month column contains '04', I would like to create a date column that contains: '2014-04-03'
This is my code:
CONCAT('2014-',month,'-',day) as date;
It doesn't work and I'm not quite sure how to concatenate additional text onto the column.
I would like to note that I'm not sure converting to date format is an option for me. I would prefer to keep it in CHARARRAY format since I would like to join with another file that has date stored in CHARARRAY format.
Assuming this is the data file called dateExample.csv:
Surender,02,03,1988
Raja,12,09,1998
Raj,05,10,1986
This is the script for pig:
A = LOAD 'dateExample.csv' USING PigStorage(',') AS(name:chararray,day:chararray,month:long,year:chararray);
X = FOREACH A GENERATE CONCAT((chararray)day,CONCAT('-',CONCAT((chararray)month,CONCAT('-',(chararray)year))));
dump X;
You will get the desired output:
(02-3-1988)
(12-9-1998)
(05-10-1986)
Explanation:
When we try to concat like this:
X = FOREACH A GENERATE CONCAT(day,CONCAT('-',CONCAT(month,CONCAT('-',year))));
We get following exception :
ERROR 1045:
<line 2, column 45> Could not infer the matching function for org.apache.pig.builtin.CONCAT as multiple or none of them fit. Please use an explicit cast.
So we need to explicitly cast the day,month and year values to chararray and it works!!