I have an SQLite database and I want to dump and read individual statements from the dump. The problem I am encountering is that the individual statements can span multiple lines. So, I can't just read the dump file line-by-line. Is there a way to change the default line separator for .dump/.output command?
The .dump command always use a new-line as separator.
Any combination of characters (except a single ') is valid inside a string, and semicolons are valid inside a trigger body. To be able to read individual statements, you'd have to implement an SQL parser.
Related
I guess that it's valid for MySQL, however, I cannot find anything about SQLite.
Basically, I have a table which is named 'CUSTOMER'.
So I create an attribute like this:
.. Image BLOB .. after that my insert statement looks like this:
INSERT INTO CUSTOMER(1,LOAD_FILE(D:/Project/Images/X.jpg));
However, the LOAD_FILE tag is not working and I don't know how to insert an image or if we can do that.
If you're using the sqlite3 shell, the relevant function is readfile().
If you're doing this from your own program, you have to read the file into a byte array and bind it as a blob to the desired column in an insert. The exact details vary depending on language and sqlite bindings, but you shouldn't ever have to convert it to a blob literal string and embed that directly into a statement.
You can store an image as a BLOB, but you'd have to insert it as a a series of bytes using something like :-
INSERT INTO CUSTOMER (image_column, other_column) VALUES(x'0001020304........','data for the first other column');
So you'd need to convert the file into a hex string to save it.
However, it's not really recommended to store images but to rather store the path to the image and then retrieve the file when you want to display/use the image.
Saying that, SQLite can, for smaller images (say 100K), actually be more efficient 35% Faster Than The Filesystem.
You must use the cmd command line (windows) to insert the attachment. The sqllitespy (version 1.9.13) does not support de command from the program command line.
You should acess you database first with the CMD and after that;
update (your table) set (column) = readfile ('dir where the files are stored'||num||ยด.jpg);
On my website I want to display lines of code from a database.
When trying to introduce the CSS into the database I get a syntax error, although this statement works perfectly fine with HTML. Of course before inserting the HTML into the database I had to escape the < > tags. Do I also have to escape characters in the CSS?
INSERT INTO table (foreignk,language,content)
VALUES
(1,'CSS','cssplaceholder');
You don't have to escape your HTML, you need to escape your data. That means any and all values. Remember to escape for the context you're writing to. For SQL that means the escaping appropriate for your SQL dialect (e.g. MySQL), but HTML, JSON and CSS, for example, are different.
The < character is meaningless to MySQL inside a string. Don't escape it. Keep your values as "raw" as possible. The idea is to escape them only for the context in which they're displayed, and to do that when they're displayed, not before.
If you HTML-escape your data, you'll have to unescape it when using it in an non-HTML context and then it gets ugly. This is why you often get emails with subjects containing the actual text & which is a sign someone's got it very wrong.
If you're doing this programmatically look at using prepared statements with placeholder values.
I am creating a C++ program which will output a series of SQL statements (create, insert, etc) and write them to a file. This file will be used to create and populate a SQLite3 database.
I need to ensure that and values inserted are properly escaped so they can fit within the double quoted string (in the insert statement). Since there is no SQLite database available (this program just writes to a text file), I cannot use prepare. Can someone tell me which characters need to be escaped and how?
So far I've only found that the ' character needs to be escaped with another '
Inside a string, the only character to be escaped is the quote ' itself.
As for table/column names, you need to quote them if they conflict with SQL keywords.
I'm using SQLite, and I'm unable to find a way to locate the index of the last occurrence of a character. For example, the records that I need to parse are:
test123.contoso.txt
testABC.contoso.atlanta.docx
another.test.vb
I would appreciate if anybody can point me in the direction how I can parse the file extensions (txt, docx, vb) from these records through a SQLite query. I've tried using the REVERSE function, but unfortunately SQLite doesn't include this in it's toolbox.
You can adapt the solution in How to get the last index of a substring in SQLite? to extract the extension.
select distinct replace(file, rtrim(file, replace(file, '.', '')), '') from files;
If you want to check whether a file name has a specific extension, you can use LIKE:
... WHERE FileName LIKE '%.txt'
However, it is not possible with the built-in functions to extract the file extension.
If you need to handle the file extension separately, you should store it separately in the database, too.
Does anybody have any tips on utilities that can be used to bulk load data that is stored in delimited text files into an SQLite database?
Ideally something that can be called as a stand-alone program from a script etc.
A group I work with has an Oracle Database that's going to dump a bunch of data out to file and then load that data into an SQLite database for use on a mobile device and are looking for the easiest way to implement that sort of scenario.
Check out the sqite .import command - it does exacty this.
You can set the separator with the .separator command
sqlite3 myDatabase
create table myTable (a, b, c);
.separator ','
.import myFile myTable
Why do you want a text file?
Just use Java which does have easily available libraries for Oracle and SQLite access. Connect to both databases and just select from one db and insert into another with no additional complexity of CSV, which is not a very well defined format and will give you problems with character encoding, quotes, comas/tabs or semicolons, newlines etc. in your data.