I want to modify a generator value in Delphi with Firebird 2.5. The Statement is:
ALTER SEQUENCE GEN_NAME RESTART WITH value . What I want is that the value not to be a number but a variable or a parameter like:
ALTER SEQUENCE GEN_TELAGENT_ID RESTART WITH val; where val get a different integer value I don't know yet.
I hope I made myself understood. Sorry for my not so good English.
Thanks for the answers.
use a parameter, with your preferred components it should work.
myQuery.SQL.Text := 'alter sequence gen_telagent_id restart with :val';
myQuery.Params.ParamByName('val').AsInteger := val;
myQuery.ExecSQL();
Actual syntaxis may vary depending on the components you use to connect to Firebird.
Related
I'm trying to update a column named value in a dbf-file. Since value is a reserved word I need to add the tablename to the query. So this works:
UPDATE "C:\TEMP\TEST_PARAM.DBF" SET TEST_PARAM.value='new value' WHERE Id='Some ID';
But now I have the problem that many of my dbf-files start with numbers in the filenames and following does not work:
UPDATE "C:\TEMP\0016_PARAM.DBF" SET 0016_PARAM.value='new value' WHERE Id='Some ID';
I've tried enclosing the table_name in single quotes, double quotes, [,... but nothing of that works. Is there something else I could try?
You don't say what language you're doing this in, but here we go in C#. The same approach should work in any language.
You need to open the DBF under an alias, and you need to be able to send multiple commands through OLEDB.
This should work.
* -- Open the dbf in the first available work area under the alias 'param'.
* -- Now you don't have to worry about the zeroes.
OleDbCommand myCommand = new OleDbCommand(#"execscript([use 'C:\TEMP\0016_PARAM.DBF' in 0 alias param])", myConnection);
var result = myExecuteNonQuery();
* -- Now do the update, referring to the alias, not the DBF filename.
myCommand = new OleDbCommand(#"execscript([update param set param.value='new' where id='some id'])", myConnection);
result = myCommand.ExecuteNonQuery();
Regarding the square brackets, Visual FoxPro has three default string delimiters, namely the usual single and double quotes, but also square brackets.
So we're using the double quotes for the C# string. The Visual Foxpro command we're running via ExecScript needs quotes too, around 'new' and 'some id', so that's using single quotes. But we need to pass that command to Execscript as a string, so that string is using the brackets.
I am a newcomer to coding in general and I want to learn basic Lua scripting for my own hobby.
After working on a Lua script, the syntax all seems to be without error but I have come across one issue that I don't understand, I broke it down to this basic function:
{$lua}
ID1 = "10"
ID2 = "0"
if (ID1 ~= nil and ID1 == "10") then
writeInteger(ID2,"25")
end
print(ID2)
The issue is that the writeInteger does not seem to work at all, ID2 remains at value "0" while it should become "25".
Any help would be greatly appreciated.
This is not valid Lua, or at least it isn't valid vanilla (out-of-the-box) Lua, and since you have not specified anything else, there is not much we can do to help. I will assume writeInteger is a valid function (since your interpreter isn't complaining about a call to a nil value), but I don't think it works as you expect.
If you want to set the ID2 variable to 25, simply write:
ID2 = 25
Lua will convert the string type to an integer type automatically. You can run print(type(ID2)) to confirm this
If you are using cheat engine (as a quick google search suggests) the writeInteger function requires an address and a value.
function writeInteger(Address, Value): Boolean - Returns true on success.
I am not sure if ID2, a Lua variable, is a valid address, but I am sure that "25" is not an integer. You should remove the quotation marks to start, and since the function returns a boolean you can see if the function was successful by doing:
print(writeInteger(ID2, 25))
Lua uses pass by value for primitive types like numbers, booleans and strings. So if you pass a number to a function like writeInteger, it creates a local copy within the function. The function can alter this copy but it will have no effect on caller (of writeInteger in this case). I don't know how writeInteger is supposed to work but if you want to call a function which alters its argument you can create a table and pass that. Tables are still passed by value but the "value" of a table is its memory address (so in effect tables are passed by reference and you can alter the contents of a table by passing it to a function).
See more here
Function/variable scope (pass by value or reference?)
I need to add days to date in HANA stored procedure, but I am getting error message
ERROR WHILE parsing DATE/ TIME
I use this statement where p_end_date is parameter of my stored procedure.
v_end_date_plus := add_days (TO_DATE(' || p_end_date || ' , 'YYYY-MM-DD' ), 90)
Is there is any other way or what I am doing wrong in it ?
Even though you didn't post what error you receive, I guess that the problem in your code is the way you referenced your input variable.
v_end_date_plus := add_days ( :p_end_date , 90);
With the colon (:) in front of the parameter you should be able to use it without having to cast it into a different data type.
#LarsBr. is correct that you need a colon (:) to reference the variable, and that if it is really a DATE type, you don't need to convert TO_DATE again.
But additionally, in your example you have some mixup with quotes and concatenation that makes me think that you actually want to construct some character string using p_end_date. This would need conversion to a date first:
p_end_date := '2016-05-03'; -- for example
v_end_date_plus := add_days(TO_DATE( :p_end_date , 'YYYY-MM-DD' ), 90);
The part ' || p_end_date || ' in your example also looks a bit like the whole code was actually part of string to be used in EXEC or similar. If that's the case, you need to have escaped single-quotes for both parameters, e.g.
exec 'v_end_date_plus := add_days(TO_DATE(''' || :p_end_date || ''', ''YYYY-MM-DD'' ), 90)';
p_end_date should be a varchar field, or the appropriate string literal used in your technology. It should not be enclosed in quotes.
v_end_date_plus := add_days (TO_DATE(p_end_date , 'YYYY-MM-DD' ), 90)
EXPLANATION USING ORACLE AS REFERENCE :
In Oracle database, the default date format is dd-MON-RR or dd-MON-YYYY.
So, if I use correct date format to p_end_date variable, I am able obtain output.
However, if I diverge from this default format,my attempt would error out.
So, if I want the flexibility to redefine p_end_date in format of my choice, and not as per default settings, it should be a String literal.(varchar in Oracle ).
EDIT:
The essence of this answer was just to suggest that the variable should be passed as a varchar. Borrowing from Lars Br's suggestion below to modify the p_end_date variable's syntax:
v_end_date_plus := add_days (TO_DATE(:p_end_date , 'YYYY-MM-DD' ), 90)
As I remembered 'tick' from FIG-Forth, it could be used without abortion when a word wasn't in the wordlist:
' the_word
gave a reference to the word if it was in the word-list and gave 'false' otherwise.
Is it possible to construct something like that in ANS Forth to be used with [if], [then] and [else]?
I guess something like this:
: tick ( a u -- xt|f ) bl word find 0= if drop 0 then ;
The FIG-Forth document says:
Leaves the parameter field address of dictionary word nnnn. As a
compiler directive, executes in a colon-definition to compile the
address as a literal. If the word is not found after a search of
CONTEXT and CURRENT, an appropriate error message is given.
Although it is entirely possible the version of FIG-Forth you where using did not abide by the standard, and returned false.
A user will enter a string value for a date. StrToDate will be used to convert the string value to a DateTime. If the user enter's a date with a 2 digit year the date may be parsed as the current century (20xx) or the previous century (19xx).
To clear up any ambiguity, how do require the user enter a 4 digit year?
if isFourDigitYear(txbDate.Text) then
date := StrToDate(txbDate.Text)
else
ShowMessage('enter date with 4 digit year');
I think that the best choice would be to use TDateTimePicker
http://docwiki.embarcadero.com/Libraries/XE6/en/Vcl.ComCtrls.TDateTimePicker
If you are using older Delphi than Delphi 2009 with update pack 3 then you would wanna read next article to fix a bug found in TDateTimePicker.
http://www.tmssoftware.com/site/blog.asp?post=117
This bug has been fixed in newer versions.
Now if you are using FireMonkey take care about using TDateTimePicker as in Delphi XE3 it has a bug which srews up the date when entered through keyboard (can still be picked fine by mouse). I'm not sure if this was already fixed in later versions of Delphi or not.
If using of TDateTimePicker is out of the question then definitly use TMaskedEdit instead of regular TEdit since the chosen mask forces user to enter in text in proper format.
http://docwiki.embarcadero.com/CodeExamples/XE6/en/EditMask_(Delphi)
EDIT: The best advantage of using TDateTimePicker is that it automatically uses Date Time format that has been set on that specific system.
This means that date time format used will be the one user is used to. So there will be no mistakes in case if user local settings use dd/mm/yy format instead of mm/dd/yy.
One possibility is this:
FUNCTION IsFourDigitYear(DateStr : STRING ; DateSep : CHAR = '/') : BOOLEAN;
VAR
P : Cardinal;
BEGIN
DateStr:=DateStr+DateSep; Result:=TRUE;
REPEAT
P:=POS(DateSep,DateStr);
IF P=5 THEN EXIT;
DELETE(DateStr,1,P)
UNTIL DateStr='';
Result:=FALSE
END;
It will check that there is a part of the given string that has 4 characters.
It currently won't check if that part is numerical (ie. only contains digits). And it will require you to pass in the seperator character used if you want it to be truly international - there are some countries that use '-' as a date seperator, and most other countries in the world doesn't use the strange M/D/Y format, but either D/M/Y or Y/M/D format (where "/" may be "-" in some countries).
If you want a truly international function that also checks if the four-digit part is actually in the year part of the currently valid date format, then it'll need a much more complex parser. The above may get you started, however...