[sqlite] how to check the file is a sqlite database file?
Hello All, Is there any way to know whether a certain file is sqlite database file or not? I am using sqlite 2.8.16. My requirement is , I give user an option to select a file as a sqlite database file, so if user makes a mistake in selecting a proper sqlite database file,I want to prevent the further processing and prompt the user to select correct file. (I don't want to give any extension to the database file.) Is there any sqlite api /code snippet which tells me whether the file is of sqlite database type or not? Thanking you in advance.. Regards, Yogesh Joshi
[sqlite] checking the database status
hello, i am working on sqlite 2.8.16 and my requirement is when i use the sqlite_open function i want to display error message if the database is not present.I don't want a new database with the wrong name to be created each time i use the sqlite_open function. I checked for the error parameter in the sqlite_open function but each time it returns null. so what is the solution for the above requirement.? Thanks in advance Regards Yogesh
[sqlite] unable to install sqlite2.8.16 on mac os x 10.3
Hello all, I tried to install sqlite 2.8.16 on mac os x 10.3 . when i tried to install from .dmg file,a separate drive was crated and three files namely sqlite,sqlite.a and sqlite.h were created when i tried to execute the sqlite file i got the error saying that linncurses5.4.dylib is not there in the lib folder. so i tried to build sqlite from source code.but again there i got the erro gcc not installed. how to proceed further.
[sqlite] sqlite multithreading
Hi! Problem: 1 - I need some help using sqlite3 with multithreading. Here is an overview of present situation: - I am using sqlite 3.0.8 I have two threads (A B) working at the same time. Thread A is used to query database while thread B is being used for writing to the database. Everything works right if only thread B is running. But when thread A runs while thread B is still running an error occurs. The error is: #8220;library routine called out of sequence#8221;. But this error is not emitted always, 1 out of 3 times this operation completes successfully. No action is can be preformed on the database when the error occurs. It even not closes the database. Both threads are using same sqlite connection. I am using sources from sqlite-source-3_0_8.zip compiled (with #8211;DTHREADSAFE=1) as a sub-project inside my own project using kdevelop. (In the mean time I have come across the following in sqlite mailing list archive: - it could be the case that the same database connection is being used simultaneously by two or more threads. But I have seen some applications do this successfully with a single connection. ) Problem: 2 - I need some tips on how can I use sqlite inside my project using kdevelop (i.e. without using sqlite-source-3_0_8.zip). Thanks in advance Yogesh M Yahoo! India Matrimony: Find your life partner online Go to: http://yahoo.shaadi.com/india-matrimony
[sqlite] Problem creating TRIGGER
Hi! I am very new to sqlite. I am having problem creating a trigger. Here is the statement: - sqlite CREATE TRIGGER dat.on_master_insert INSERT ON dat.master_table FOR EACH ROW BEGIN INSERT INTO dat.url_stats(new.file_name, '0', '0', '1'); END; SQL error: near .: syntax error The problem is near new.file_name, as when I access the database through a C++ program while using master_table instead of dat.master_table, same error is emitted. What the statement intends to do is to insrt a record in url_stats table whenever a new row is added to master_table. I am using sqlite 3.0.8. Thanks in advance Yogesh M Chandigarh, India http://mylinuxapps.tripod.com
[sqlite] Problem creating TRIGGER
Hi! I am very new to sqlite. I am having problem creating a trigger. Here is the statement: - sqlite CREATE TRIGGER dat.on_master_insert INSERT ON dat.master_table FOR EACH ROW BEGIN INSERT INTO dat.url_stats(new.file_name, '0', '0', '1'); END; SQL error: near .: syntax error The problem is near new.file_name, as when I access the database through a C++ program while using master_table instead of dat.master_table, same error is emitted. What the statement intends to do is to insert a record in url_stats table whenever a new row is added to master_table. I am using sqlite 3.0.8. Thanks in advance Yogesh M Chandigarh, India http://mylinuxapps.tripod.com
[sqlite] A problem with the select statement
Hi! I am using sqlite 3.05 beta. I have created a table containing a field named 'title'. When I run the SQL Command : - select count(*) from master_table where title = title output is 885, i.e. count of all the rows in the table, whereas it should have returned the number of rows in which value of the field title is title (which is actually 10). Perhaps sqlite is comparing value of column named title with the column itself. Can somebody please help, Yogesh M Chandigarh, India http://mylinuxapps.tripod.com
[sqlite] Let us make SQLite more powerful
Hello everyone, This is espcially for Dr. Hipp. First I will try to highlite the reasons as to why I am raising this topic just to establish proper grounds for what I am going to Say and Suggest. I am a software developer using VB as my main development tool and an trying to learn Delphi but the process is very slow for me as learning Delphi does'nt come in my priority. I don't know C or C++ (in fact I left C/C++ behind when I saw VB version 2.0) and am not well versed with SQL scripting either. I also work as a freelance consultant for a few firms here in my region (Rajkot, Gujarat, INDIA). My areas of consultancy are computerising business operatins, helping my clients to convert their manual process to computer, help clients in purchasing the best computer harware/software appropriate to their business requirement, managing software development of clients and helping them develop their own software inhouse by their own inhouse comuter talents, suggest them which back end database to use for their requirements, etc.. etc... I have been following SQLite's progress for quite some time now. I have got a few IDEAS regarding enhancements to SQLite to make it even more powerfull and faster than what it is today. Before I go any further. Let me confess that I have never used SQLite in any commercial projects because I feel it requires more work to use SQLite in VB. And for people like me working in VB the question of SIZE is immaterial, what we people prefer the mose it ease of use. The features that I am suggesting here will not affect the current functionality of SQLite in any but it will just enhance it in multi folds. So here are my IDEAS: --- Storing Collections Of Values In A Single Column - Traditional relational databases restrict one to storing one value in each column. Let us add such a facility to SQLite to store collections of values in a single column. With collections, one would no longer need to create multiple columns (or separate tables) for multiple street addresses, phone numbers, status codes, and so on. Instead, one just define a column as a collection, and can store as many or as few values in that column as one wants. There should be no limit on the number of values a collection column can hold. I think Collection columns are well suited for situations where one has an unknown number of data items of the same type. Consider the case of the Phone column. Instead of allowing only one telephone number or perhaps a small, fixed number (Phone1, Phone2, and so on), one can define the Phone column as a collection. If some rows have a dozen phone numbers while most others have only one or two, a collection works well (I feel so). When multiple values are added to the collection, SQLite would (probably) delimits multiple values with a separator character. I think that in many cases, one can use collections to replace foreign tables and, thereby, eliminate joins that would have to be executed to retrive data. This can dramatically improve query performance. To query collections, SQLite can inmplement an ANY clause in the SELECT statement as an extension to ANSI SQL to conveniently access the collection values either individually or as a group. Storing User-Defined Structures In A Single Column -- SQLite can provide facility to allow the user to create and define structures, or groups of columns separately (kind of separate logical table), and store those structures in a single column in the main table. This grouping can make it easier to define tables that happen to contain the same kind of information. Structures should be allowed to include other structures, but should not be allowed to be defined recursively. As per previous suggestion just like normal columns, structures can be collections. In effect, this lets one nest an entire table in a single column. Moreover, because one can nest collections and structures to any depth, one can store even highly complex objects in a single column. At the SQL from just add an extensions that lets one access the entire structure as a single entity, or directly access specific components within the structure. For example, one might define an Address structure that contains Street, City, State, and ZipCode columns. Let us assume that this Address structure appears both in the Customers table and in the Employees table. Say when one's company goes multi-national and one need to redefine the Address structure to allow for international address formats generally one whould have to make changes in all such Tables which contain such informations so loking at the example one would have to make changes in teh Customer Table as well as in emplouees Table. Imagine how easy it can get as one will only have to make change in the schema in one place: the definition
