I have a table with two columns:
1) id SERIAL PRIMARY KEY 2) BYTEA
I am trying to fetch all the rows using PGresult * res = PQexecParams(conn, "select * from table",0,NULL,NULL,NULL,NULL,1); ==> The last argument = 1 specify results to be in binary format.
Due to the last argument, I am able to fetch BYTEA column properly but the "id" column is also returned in a format that I can't understand(probably in BYTEA format). Is there a way to convert the "id" value returned by the above mentioned PQexecParams to integer? I am using PQgetvalue API to fetch results.
Related
I have table with a Varchar field. See structure.
IMAGE_KEY VARCHAR2(32 BYTE)
DOC_TYPE VARCHAR2(8 BYTE)
DOC_KEY VARCHAR2(256 BYTE)
LAST_UPDT DATE
UPDT_USER VARCHAR2(6 BYTE)
BLK_HANDLE VARCHAR2(16 BYTE)
DOC_KEY_ID NUMBER(15,0)
FE_ID NUMBER(15,0)
I want to create a view and convert the field Doc_Type which is varchar to a Number field in the view using the sql scripts.
SELECT IMAGE_KEY,
DOC_TYPE,
cast(DOC_KEY as NUMBER(15)) as DOC_KEY ,
LAST_UPDT,
UPDT_USER,
BLK_HANDLE,
DOC_KEY_ID,
FE_ID
FROM rdo
and
SELECT IMAGE_KEY,
DOC_TYPE,
TO_NUMBER (TRIM (DOC_KEY)) as DOC_KEY ,
LAST_UPDT,
UPDT_USER,
BLK_HANDLE,
DOC_KEY_ID,
FE_ID
FROM rdo
I get the following error when I extract data from the views created by any of the scripts above.
An error was encountered performing the requested operation:
ORA-01722: invalid number
01722. 00000 - "invalid number"
*Cause: The specified number was invalid.
*Action: Specify a valid number.
Vendor code 1722
How do I successfully convert the varchar field to a Number field using a create view statement.
I am trying to update a JSONB field in one table with data from another table. For example,
update ms
set data = data || '{"COMMERCIAL": 3.4, "PCT" : medi_percent}'
from mix
where mix.id = mss.data_id
and data_id = 6000
and set_id = 20
This is giving me the following error -
Invalid input syntax for type json
DETAIL: Token "medi_percent" is invalid.
When I change medi_percent to a number, I don't get this error.
{"COMMERCIAL": 3.4, "PCT" : medi_percent} is not a valid JSON text. Notice there is no string interpolation happening here. You might be looking for
json_build_object('COMMERCIAL', 3.4, 'PCT', medi_percent)
instead where medi_percent is now an expression (that will presumably refer to your mix column).
Using Postgres 11.2.9 (ubuntu),
In my database, I have a jsonb field containing values that look like this :
[1618171589133, 1618171589245, 1618171589689]
I'd like to retrieve rows where the first element is lower than a specific value. I've tried this :
SELECT * FROM user.times WHERE time ->> 0 < 1618171589133
but I get the following error : ERROR: operator does not exist: text = bigint
Should I somehow cast the time value to numeric value ? I've tried time ->> 0::numeric but I actually don't know what to do.
The ->> operator returns the element at given position as text, which you can then convert to integer (or as it seems in this case, bigint), as you would normally do in postgres, using the :: as suffix.
SELECT * FROM user.times WHERE ((time ->> 0)::bigint) < 1618171589133
I have a table with a uuid column, and some of the rows are missing the data. I need to insert data into this uuid column. The data is entered manually, so we are suffixing with other column data to differentiate, but it gives me an error.
UPDATE schema.table
SET uuid_column = CONCAT ('f7949f56-8840-5afa-8c6d-3b0f6e7f93e9', '-', id_column)
WHERE id_column = '1234';
Error: [42804] ERROR: column "uuid_column" is of type uuid but expression is of type text
Hint: You will need to rewrite or cast the expression.
Position: 45
I also tried
UPDATE schema.table
SET uuid_column = CONCAT ('f7949f56-8840-5afa-8c6d-3b0f6e7f93e9', '-', id_column)::uuid
WHERE id_column = '1234';
Error: [22P02] ERROR: invalid input syntax for uuid: "f7949f56-8840-5afa-8c6d-3b0f6e7f93e9-1234"
An UUID consists of 16 bytes, which you see displayed in hexadecimal notation.
You cannot have a UUID with fewer or more bytes.
I recommend using the type bytea if you really need to do such a thing.
In MongoDB you can retrieve the date from an ObjectId using the getTimestamp() function. How can I retrieve the date from a MongoDB ObjectId using Postgresql (e.g., in the case where such an ObjectId is stored in a Postgres database)?
Example input:
507c7f79bcf86cd7994f6c0e
Wanted output:
2012-10-15T21:26:17Z
In Mongodb documentation the Objectid is formed with a timestamp as the first 4 bytes, but this is represented in hexidecimal. Assuming that hexidecimal value is stored as a string in PostgreSQL, then the following query will extract just the first 8 characters of that objectid, convert that to an integer (which is seconds from 1970-01-01) then convert that integer to a timestamp. For example:
SELECT TO_TIMESTAMP(int_val) ts_val
FROM (
SELECT ('x' || lpad(left(objectid,8), 8, '0'))::bit(32)::int AS int_val
FROM (
VALUES ('507c7f79bcf86cd7994f6c0e')
) AS t1(objectid)
) AS t2
;
Converting a hexadecimal string to integer is discussed here:
Convert hex in text representation to decimal number
The first answer is quite excellent. This one expands the answer by making a reusable function out of it.
create function extractMongoTimestamp(text) RETURNS TIMESTAMP WITH TIME ZONE
as
'SELECT TO_TIMESTAMP(int_val) ts_val
FROM (
SELECT (''x'' || lpad(left(objectid,8), 8, ''0''))::bit(32)::int AS int_val
FROM (
VALUES ($1)
) AS t1(objectid)
) AS t2'
language sql
immutable
RETURNS null on null input;
Use it in your query:
select extractMongoTimestamp('507c7f79bcf86cd7994f6c0e');