473,397 Members | 1,969 Online
Bytes | Software Development & Data Engineering Community
Post Job

Home Posts Topics Members FAQ

Join Bytes to post your question to a community of 473,397 software developers and data experts.

eval function?

-
i am using a regular expression in a select statement inside a function.
how do i dynamically insert a variable into the regexp?

eg. SELECT string ~ '\\d{X}'

where X is the dynamic variable.

I tried '\\d{' || X || '}'

obviously it didn't work.

is there an equivalent of javascript's eval() in postgresql?
Nov 23 '05 #1
2 10162
-
- wrote:
i am using a regular expression in a select statement inside a function.
how do i dynamically insert a variable into the regexp?

eg. SELECT string ~ '\\d{X}'

where X is the dynamic variable.

I tried '\\d{' || X || '}'

obviously it didn't work.

is there an equivalent of javascript's eval() in postgresql?


somebody......... help me out please..

i want to put a variable into a WHERE clause e.g

WHERE
columnname ~ X

(X is a variable).

how should i do it?

columnnane ~ '' || X ||'' doesn't work.
Nov 23 '05 #2
Stu
- wrote:
- wrote:
i am using a regular expression in a select statement inside a function.
how do i dynamically insert a variable into the regexp?

eg. SELECT string ~ '\\d{X}'

where X is the dynamic variable.

I tried '\\d{' || X || '}'

obviously it didn't work.

is there an equivalent of javascript's eval() in postgresql?


somebody......... help me out please..

i want to put a variable into a WHERE clause e.g

WHERE
columnname ~ X

(X is a variable).

how should i do it?

columnnane ~ '' || X ||'' doesn't work.


I'm not sure what you are asking. If you are talking about PL/pgSQL, and
you don't want to do something with the result set, then you can just build
the query in a varchar and run it using EXECUTE. Something like this:

CREATE OR REPLACE FUNCTION some_function(text) RETURNS BOOLEAN AS $$
DECLARE
my_query VARCHAR(100);
my_text AS ALIAS FOR $1;
BEGIN
my_query := 'SELECT * FROM some_table WHERE some_column = '
|| quote_literal(my_text) || ';';
EXECUTE my_query;
RETURN TRUE;
END;
$$ LANGUAGE plpgsql;
Stu

Nov 23 '05 #3

This thread has been closed and replies have been disabled. Please start a new discussion.

Similar topics

4
by: Jean-Sébastien Bolduc | last post by:
Hello, I would like to associate a local namespace with a lambda function. To be more specific, here is exactly what I would want: def foo(): a = 1 f = lambda x : a*x return f
9
by: HikksNotAtHome | last post by:
This is a very simplified example of an Intranet application. But, is there an easier (or more efficient) way of getting the decimal equivalent of a fraction? The actual function gets the select...
12
by: knocte | last post by:
Hello. I have always thought that the eval() function was very flexible and useful. If I use it, I can define functions at runtime!! However, I have found a case where eval() does not work...
18
by: Joe Fallon | last post by:
I have some complex logic which is fairly simply to build up into a string. I needed a way to Eval this string and return a Boolean result. This code works fine to achieve that goal. My...
3
by: Pauljh | last post by:
Hi All, I'm running some javascript over a server side generated web page and have multiple generated empty select statements, that I want to populate when the page is loaded. As HTML doesn't do...
7
by: Darko | last post by:
Hello, I have this particular problem with eval() when using Microsoft Internet Explorer, when trying to define an event handler. This is the code: function BigObject() { this.items = new...
6
by: vasudevram | last post by:
Hi group, Question: Do eval() and exec not accept a function definition? (like 'def foo: pass) ? I wrote a function to generate other functions using something like eval("def foo: ....") but...
2
by: Florian Loitsch | last post by:
hi, What should be the output of the following code-snippet? === var x = "global"; function f() { var x = 0; eval("function x() { return false; }"); delete x; alert(x); }
6
by: RandomElle | last post by:
Hi there I'm hoping someone can help me out with the use of the Eval function. I am using Access2003 under WinXP Pro. I can successfully use the Eval function and get it to call any function with...
10
by: Gordon | last post by:
I have a script that creates new objects based on the value of a form field. Basically, the code looks like this. eval ('new ' + objType.value + '(val1, val2, val3'); objType is a select with...
0
by: emmanuelkatto | last post by:
Hi All, I am Emmanuel katto from Uganda. I want to ask what challenges you've faced while migrating a website to cloud. Please let me know. Thanks! Emmanuel
0
BarryA
by: BarryA | last post by:
What are the essential steps and strategies outlined in the Data Structures and Algorithms (DSA) roadmap for aspiring data scientists? How can individuals effectively utilize this roadmap to progress...
1
by: nemocccc | last post by:
hello, everyone, I want to develop a software for my android phone for daily needs, any suggestions?
1
by: Sonnysonu | last post by:
This is the data of csv file 1 2 3 1 2 3 1 2 3 1 2 3 2 3 2 3 3 the lengths should be different i have to store the data by column-wise with in the specific length. suppose the i have to...
0
by: Hystou | last post by:
There are some requirements for setting up RAID: 1. The motherboard and BIOS support RAID configuration. 2. The motherboard has 2 or more available SATA protocol SSD/HDD slots (including MSATA, M.2...
0
jinu1996
by: jinu1996 | last post by:
In today's digital age, having a compelling online presence is paramount for businesses aiming to thrive in a competitive landscape. At the heart of this digital strategy lies an intricately woven...
0
tracyyun
by: tracyyun | last post by:
Dear forum friends, With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each...
0
agi2029
by: agi2029 | last post by:
Let's talk about the concept of autonomous AI software engineers and no-code agents. These AIs are designed to manage the entire lifecycle of a software development project—planning, coding, testing,...
0
isladogs
by: isladogs | last post by:
The next Access Europe User Group meeting will be on Wednesday 1 May 2024 starting at 18:00 UK time (6PM UTC+1) and finishing by 19:30 (7.30PM). In this session, we are pleased to welcome a new...

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.