I have a VARCHAR(1000) column of prices with dollar signs (e.g. $100) and I have created a new NUMERIC(15,2) column, which I'd like to set equal to the prices in the VARCHAR column.
This is what worked for me in MySQL:
UPDATE product_table
SET cost = REPLACE(REPLACE(price, '$', ''), ',','');
but in PostgreSQL it throws an error:
ERROR: column "cost" is of type numeric but expression is of type character
LINE 2: SET cost = REPLACE(REPLACE(price, '$', ''), ',','');
^
HINT: You will need to rewrite or cast the expression.
I tried to follow the hint and tried some Google searches for examples, but my small brain hasn't been able to figure it out.
In PostgreSQL you can do this in one swoop, rather than replacing '$' and ',' s in separate calls:
UPDATE product_table
SET cost = regexp_replace(price, '[$,]', '', 'g')::numeric(15,2);
In regexp_replace the pattern [$,] means to replace either of '$' or ',' with the replace string (the empty string '' in this case), and the 'g' flag indicates that all such patterns need to be replaced.
Then you need to cast the resulting string to a numeric(15,2) value.
Simply cast the result of REPLACE with cast .. as numeric.
Try this:
UPDATE product_table
SET cost = CAST(REPLACE(REPLACE(price, '$', ''), ',','') AS NUMERIC);
I wouldn't suggest having this table structure though, because it can lead to anomalies (cost value doesn't reflect the price value).
Related
I hava data in my database and i need to select all data where 1 column number is between 1-100.
Im having problems, because i cant use - between 1 and 100; Because that column is character varying, not integer. But all data are numbers (i cant change it to integer).
Code;
dst_db1.eachRow("Select length_to_fault from diags where length_to_fault between 1 AND 100")
Error - operator does not exist: character varying >= integer
Since your column supposed to contain numeric values but is defined as text (or version of text) there will be times when it does not i.e. You need 2 validations: that the column actually contains numeric data and that it falls into your value restriction. So add the following predicates to your query.
and length_to_fault ~ '^\+?\d+(\.\d*)?$'
and length_to_fault::numeric <# ('[1.0,100.0]')::numrange;
The first builds a regexp that insures the column is a valid floating point value. The second insures the numeric value fall within the specified numeric range. See fiddle.
I understand you cannot change the database, but this looks like a good place for a check constraint esp. if n/a is the only non-numeric are allowed. You may want to talk with your DBA ans see about the following constraint.
alter table diags
add constraint length_to_fault_check
check ( lower(length_to_fault) = 'n/a'
or ( length_to_fault ~ '^\+?\d+(\.\d*)?$'
and length_to_fault::numeric <# ('[1.0,100.0]')::numrange
)
);
Then your query need only check that:
lower(lenth_to_fault) != 'n/a'
The below PostgreSQL query will work
SELECT length_to_fault FROM diags WHERE regexp_replace(length_to_fault, '[\s+]', '', 'g')::numeric BETWEEN 1 AND 100;
I have field that has up to 9 comma separated values each of which have a string value and a numeric value separated by colon. After parsing them all some of the values between 0 and 1 are being set to an integer rather than a numeric as cast. The problem is obviously related to data type but I am unsure what is causing it or how to fix it. The problem only exists in the case statement, the split_part function seems to be working perfect.
Things I have tried:
nvl(split_part(one,':',2),0) = COALESCE types text and integer cannot be matched
nvl(split_part(one,':',2)::numeric,0) => Invalid input syntax for type numeric
numerous other cast/convert variations
(CASE WHEN split_part(one,':',2) = '' THEN 0::numeric ELSE split_part(one,':',2)::numeric END)::numeric => runs but get int value of 0
When using the split_part function outside of case statement it does work correctly. However, I need the result to be zero for null values.
split_part(one,':',2) => 0.02068278096187390979 (expected result)
When running the code above I get zero but expect 0.02068278096187390979
Field "one" has the following value 'xyz: 0.02068278096187390979' before the split_part function.
EXAMPLE:
create table test(one varchar);
insert into test values('XYZ: 0.50000000000000000000')
select
one ,split_part(one,':',2) as correct_value_for_those_that_are_not_null ,
case
when split_part(one,':',2) = '' then null
else split_part(one,':',2)::numeric
end::numeric as this_one_is_the_problem
from test
However, I need the result to be zero for null values.
Your example does not deal with NULL values at all, though. Only addressing the empty string ('').
To replace either with 0 reliably, efficiently and without casting issues:
SELECT part1, CASE WHEN part2 <> '' THEN part2::numeric ELSE numeric '0' END AS part2
FROM (
SELECT split_part(one, ':', 1) AS part1
, split_part(one, ':', 2) AS part2
FROM test
) sub;
See:
Best way to check for "empty or null value"
Also note that all SQL CASE branches must agree on a common data type. There have been minor adjustments in the logic that determines the resulting type in the past, so the version of Postgres may play a role in corner cases. Don't recall the details now.
nvl()is not a Postgres function. You probably meant COALESCE. The manual:
This SQL-standard function provides capabilities similar to NVL and IFNULL, which are used in some other database systems.
I am attempting to run a simple UPDATE script on an integer field, whereby the trailing 2 numbers are "kept", and the leading numbers are removed. For example, "0440" would be updated as "40." I can get the desired data in a SELECT statement, such as
SELECT RIGHT(field_name::varchar, 2)
FROM table_name;
However, I run into an error when I try to use this same functionality in an UPDATE script, such as:
UPDATE schema_name.table_name
SET field_name = RIGHT(field_name::varchar, 2);
The error I receive reads:
column . . . is of type integer but expression is of type text . . .
HINT: You will need to rewrite or cast the expression
You're casting the integer to varchar but you're not casting the result back to integer.
UPDATE schema_name.table_name
SET field_name = RIGHT(field_name::TEXT, 2)::INTEGER;
The error is quite straight forward - right returns textual data, which you cannot assign to an integer column. You could, however, explicitly cast it back:
UPDATE schema_name.table_name
SET field_name = RIGHT(field_name::varchar, 2)::int;
1 is a digit (or a number - or a string), '123' is a number (or a string).
Your example 0440 does not make sense for an integer value, since leading (insignificant) 0 are not stored.
Strictly speaking data type integer is no good to store the "trailing 2 numbers" - meaning digits - since 00 and 0 both result in the same integer value 0. But I don't think that's what you meant.
For operating on the numeric value, don't use string functions (which requires casting back and forth. The modulo operator % does what you need, exactly: field_name%100. So:
UPDATE schema_name.table_name
SET field_name = field_name%100
WHERE field_name > 99; -- to avoid empty updates
I'm using PostgreSQL 9.3.
I have a varchar column in a table that can be null and I want to update it depending of its value is null or not.
I didn't manage to do a function that takes a String as argument and updates the value like this:
If the column is null, the function concatenates the current string value, a comma and the string given as argument, else it just adds the string at the end of the current string value (without comma).
So how can I make a different Update depending of the column value to update?
You can use a case statement to conditionally update a column:
update the_table
set the_colum = case
when the column is null then 'foobar'
else the_column||', '||'foobar'
end
An another approach
UPDATE foo
SET bar = COALESCE(NULLIF(concat_ws(', ', NULLIF(bar, ''), NULLIF('a_string', '')), ''), 'a_string')
I want to convert a column of type "character varying" that has integers with commas to a regular integer column.
I want to support numbers from '1' to '10,000,000'.
I've tried to use: to_number(fieldname, '999G999G999'), but it only works if the format matches the exact length of the string.
Is there a way to do this that supports from '1' to '10,000,000'?
select replace(fieldname,',','')::numeric ;
To do it the way you originally attempted, which is not advised:
select to_number( fieldname,
regexp_replace( replace(fieldname,',','G') , '[0-9]' ,'9','g')
);
The inner replace changes commas to G. The outer replace changes numbers to 9. This does not factor in decimal or negative numbers.
You can just strip out the commas with the REPLACE() function:
CREATE TABLE Foo
(
Test NUMERIC
);
insert into Foo VALUES (REPLACE('1,234,567', ',', '')::numeric);
select * from Foo; -- Will show 1234567
You can replace the commas by an empty string as suggested, or you could use to_number with the FM prefix, so the query would look like this:
SELECT to_number(my_column, 'FM99G999G999')
There are things to take note:
When using function REPLACE("fieldName", ',', '') on a table, if there are VIEW using the TABLE, that function will not work properly. You must drop the view to use it.