Programming Forums > Application Development > Delphi

wernervt · Mar 23rd, 2006, 4:12 AM

I have this table and its got a field name called value.
I would like to add up all the values and then purge it from the database.
any suggestions?
Thank you
werner

Ooble · Mar 24th, 2006, 5:39 PM

Using SQL:

(Toggle Plain Text)

SELECT SUM(value) FROM table
DELETE FROM table

(assuming "purge it" means "purge everything")

Silvanus · Mar 24th, 2006, 6:48 PM

TRUNCATE can also be used (at least in mysql) to remove all rows; it also resets auto-incrementing fields.

wernervt · Mar 27th, 2006, 12:24 AM

Thank you for your help! Im not using SQL though. ive just got an .dbf database. I just want to add all the records in a certian field and then purge them to a backup database.
Thank you for your swift response!
I really appreciate your help
Werner

Ooble · Mar 28th, 2006, 4:57 PM

The extension "DBF" is apparently used by a number of different database applications. Which one are you using?

wernervt · Mar 30th, 2006, 4:27 AM

dbaseIV

Ooble · Mar 31st, 2006, 9:13 AM

That's roughly fifteen years old, and uses its own proprietary query language, as opposed to the industry standard, SQL. I suggest a more recent DB application - MySQL or PostgreQL, perhaps? Of course, if you're tied in to this specific database software, you'll need to learn the query language. I couldn't find much on it myself - good luck.

wernervt · Apr 3rd, 2006, 12:59 AM

thanks for your help. I think i should start using SQL. is there any forums i can join to find out about how to construct an sql database and where to find a free sql program. how do you start in sql? i dont know anything about sql.

Thank you for all your help thus far

Ooble · Apr 3rd, 2006, 6:05 PM

OK, let's start from the beginning. SQL stands for Structured Query Language, and is the language you need to know when working with databases. Most database software understands SQL.

There are two main things you need to do with databases: retrieve and manipulate information. SQL provides ways to do both. To retrieve information:

(Toggle Plain Text)

SELECT forename, surname FROM people WHERE person_id > 10 ORDER BY surname;

That's a typical SQL statement, and it does a lot. It looks up the people table, and gets the forename and surname of every person with an ID number greater than 10. It then returns the list of people ordered by surname. As you can see, it's a very powerful language.

Now imagine we have a table with three columns: person_id, forename and surname. How would we put something in there?

(Toggle Plain Text)

INSERT INTO people VALUES (4, "John", "Smith");

Easy, no?

I suggest you pick up a book on SQL to find out all the different things you can do with it. To use it, you'll obviously need some database software. As I mentioned earlier, MySQL and PostgreSQL are two of the best. Download one of them and install it, and if you have any problems, let us know.

wernervt · Apr 4th, 2006, 2:51 AM

I was on the net reading up on sql language and i think it is a very powerfull language. i love building programs in delphi using databases. but i do not know waht database to use since dbase and bde is no longer supported and the growth limit is only 2GB wich is small. I would like to know what database structure to use and what opensource program can i use to construct the database. also can i use acess to make one or is the database desktop in delphi sufficient and if so wich database format. can you see my predicament. thank you for your advice. i am going to buy a book on sql but i dunno how to integrate it with a delphi program ect. i am still a novice.

Thank you very much!
Werner

Mar 23rd, 2006, 4:12 AM	#1
wernervt Newbie Join Date: Mar 2006 Posts: 10 Rep Power: 0	Add all fields in table I have this table and its got a field name called value. I would like to add up all the values and then purge it from the database. any suggestions? Thank you werner

Mar 24th, 2006, 5:39 PM	#2
Ooble I eat cake for breakfast. Join Date: Jul 2004 Location: In my box. Posts: 4,434 Rep Power: 9	Using SQL: (Toggle Plain Text) SELECT SUM(value) FROM table DELETE FROM table SELECT SUM(value) FROM table DELETE FROM table (assuming "purge it" means "purge everything") __________________ Me :: You :: Them

Mar 24th, 2006, 6:48 PM	#3
Silvanus Hobbyist Programmer Join Date: Aug 2005 Location: Hiding from... them... Posts: 110 Rep Power: 4	TRUNCATE can also be used (at least in mysql) to remove all rows; it also resets auto-incrementing fields. __________________ :wq

Mar 28th, 2006, 4:57 PM	#5
Ooble I eat cake for breakfast. Join Date: Jul 2004 Location: In my box. Posts: 4,434 Rep Power: 9	The extension "DBF" is apparently used by a number of different database applications. Which one are you using? __________________ Me :: You :: Them

Mar 31st, 2006, 9:13 AM	#7
Ooble I eat cake for breakfast. Join Date: Jul 2004 Location: In my box. Posts: 4,434 Rep Power: 9	That's roughly fifteen years old, and uses its own proprietary query language, as opposed to the industry standard, SQL. I suggest a more recent DB application - MySQL or PostgreQL, perhaps? Of course, if you're tied in to this specific database software, you'll need to learn the query language. I couldn't find much on it myself - good luck. __________________ Me :: You :: Them

Mar 27th, 2006, 12:24 AM	#4
wernervt Newbie Join Date: Mar 2006 Posts: 10 Rep Power: 0	Thank you for your help! Im not using SQL though. ive just got an .dbf database. I just want to add all the records in a certian field and then purge them to a backup database. Thank you for your swift response! I really appreciate your help Werner

Mar 30th, 2006, 4:27 AM	#6
wernervt Newbie Join Date: Mar 2006 Posts: 10 Rep Power: 0	dbaseIV

Apr 3rd, 2006, 12:59 AM	#8
wernervt Newbie Join Date: Mar 2006 Posts: 10 Rep Power: 0	thanks for your help. I think i should start using SQL. is there any forums i can join to find out about how to construct an sql database and where to find a free sql program. how do you start in sql? i dont know anything about sql. Thank you for all your help thus far

Apr 3rd, 2006, 6:05 PM	#9
Ooble I eat cake for breakfast. Join Date: Jul 2004 Location: In my box. Posts: 4,434 Rep Power: 9	OK, let's start from the beginning. SQL stands for Structured Query Language, and is the language you need to know when working with databases. Most database software understands SQL. There are two main things you need to do with databases: retrieve and manipulate information. SQL provides ways to do both. To retrieve information: (Toggle Plain Text) SELECT forename, surname FROM people WHERE person_id > 10 ORDER BY surname; SELECT forename, surname FROM people WHERE person_id > 10 ORDER BY surname; That's a typical SQL statement, and it does a lot. It looks up the people table, and gets the forename and surname of every person with an ID number greater than 10. It then returns the list of people ordered by surname. As you can see, it's a very powerful language. Now imagine we have a table with three columns: person_id, forename and surname. How would we put something in there? (Toggle Plain Text) INSERT INTO people VALUES (4, "John", "Smith"); INSERT INTO people VALUES (4, "John", "Smith"); Easy, no? I suggest you pick up a book on SQL to find out all the different things you can do with it. To use it, you'll obviously need some database software. As I mentioned earlier, MySQL and PostgreSQL are two of the best. Download one of them and install it, and if you have any problems, let us know. __________________ Me :: You :: Them

Apr 4th, 2006, 2:51 AM	#10
wernervt Newbie Join Date: Mar 2006 Posts: 10 Rep Power: 0	I was on the net reading up on sql language and i think it is a very powerfull language. i love building programs in delphi using databases. but i do not know waht database to use since dbase and bde is no longer supported and the growth limit is only 2GB wich is small. I would like to know what database structure to use and what opensource program can i use to construct the database. also can i use acess to make one or is the database desktop in delphi sufficient and if so wich database format. can you see my predicament. thank you for your advice. i am going to buy a book on sql but i dunno how to integrate it with a delphi program ect. i am still a novice. Thank you very much! Werner

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Programming Forums > Application Development > Delphi

Add all fields in table