In my java servlet application!
i am getting the checkbox selected values
as in the form of String[] by using the
String[] skills = request.getParameterValues("skills");
Now i have to store this string[] skillset values into oracle db!
I got 2 small solutions
1) i will take that string array into 1 string by appending (,) or (/).
then i will store that in db (skill VARCHAR(1000))column.
taking size like this in db column is not such a good practise.
2) I have a plan!
I will take all checkbox names as columns in db like(C Boolean, C++ boolean, Java boolean.....).
then at the time of creating table i will make all their default value as false.
when the perticuler checkbox is checked then i will insert the value true as in db for example if user select checkbox java only then i will insert in db true as it's value.
"This seems very complex process"
from my perspective these 2 options are just tricky, but not an enterprise standard use!
Is there any way to store the String array in db other than like these stuppid tricks???
Is there any data type usage in db that takes our String[]
and gives back our string[] ??
if any?
please provide me with detailed steps!!
Thanks in advance!
Recently i find one solution: VARRAY in oracle db =>
SQL> CREATE OR REPLACE TYPE smoketype IS VARRAY(3) OF VARCHAR(30)
2 /
Type created.
SQL> CREATE TABLE register (fname VARCHAR(30), lname VARCHAR(30), gender VARCHAR
(1), smoke SMOKETYPE);
Table created.
SQL> INSERT INTO register VALUES
2 (
3 'omkar','t','m',
4 smoketype('no')
5 );
1 row created.
SQL> INSERT INTO register VALUES
2 (
3 'om','T','m',
4 smoketype('no','not at all')
5 );
1 row created.
SQL> INSERT INTO register VALUES
2 (
3 'onky','T','m',
4 smoketype('no','never','not at all')
5 );
1 row created.
with the above .. i created a type that takes multiple values just like an array.
but in my servlet when i create a statement and execute a selec * from register
query then i will get
the ResultSet obj!
but how could i retrieve that smoketype array into String[] back?
how could i retrieve the string[] values?
please someone help me?
Is every value in the string array an actual string, or just a flag of some sort? true/false etc
If it's just a flag you can store it as a mask with each bit corresponding to some specific checkbox,
For example, if you have 3 checkboxes x,y,z with values true/false, you can have the mask be 3 bits, such as 101 (deonoting x = 1, y = 0, z = 1).
It's not the most descriptive way to store it as you have to keep track of actually your mask means, but it saves more space than just concatenating every value of you array
Related
How can i write a insert query in my aspx page like following???
insert into tablname(field1 ,field2, field3)values(#field1,#field2,#field1-#field2)
Here I have made field3 a computed column in database as well which is field1 -field2 in database. Values inserted in fields are in textbox so i want at runtime to calculate difference two textboxes and then insert that value in database. How can i achieve this??
No need to include field 3 in your insert.
From MSDN: Unless otherwise specified, computed columns are virtual columns that are not physically stored in the table
So you can display the computed value on your form but when you do the actual insert into the database just insert the 2 values. The value for field3 will be computed when you query the table.
There are many ways but I would suggest you to create a stored procedure with two parameters #field1 and #field2 and perform the insert statement from there, like you can create a local variable within the stored procedure which will compute the value #field3 = #field1 - #field2 and submit the values (#field1, #field2, #field3)
create table test22(field1 int, field2 int, field3 int)
create proc inserttest22
#field1 int,
#field2 int
as
declare #field3 int
set #field3 = #field1 - #field2
insert into test22 values (#field1, #field2, #field3)
go
Ok, so I have a basic table called "ledger", it contains fields of various types, integers, varchar, etc.
In my program, I used to use a query with no "from" predicate to collect all of the rows, which of course works fine. But... I changed my code to allow selecting one row at a time using "where acctno = x" (where X is the account number I want to select at the time).
I thought this must be a bug in the client library for my programming language, so I tested it in the SQLite command-line client - and it still doesn't work!
I am relatively new to SQLite, but I have been using Oracle, MS SQL Server, etc. for years and never seen this type of issue before.
Other things I can tell you:
* Queries using other integer fields also don't work
* Queries on char fields work
* Querying it as a string (with the account number on quotes) still doesn't work. (I thought maybe the numbers were stored as a string inadvertently).
* Accessing rows by rowid works fine - which is why I can edit the database with GUI tools with no noticeable problem.
Examples:
Query with no WHERE (works fine):
1|0|0|JPY|8|Paid-In Capital|C|X|0|X|0|0||||0|0|0|
0|0|0|JPY|11|Root Account|P|X|0|X|0|0|SYSTEM|20121209|150000|0|0|0|
3|0|0|JPY|13|Mitsubishi Bank Futsuu|A|X|0|X|0|0|SYSTEM|20121209|150000|0|0|0|
4|0|0|JPY|14|Japan Post Bank|A|X|0|X|0|0|SYSTEM|20121209|150000|0|0|0|
...
Query with WHERE clause: (no results)
sqlite> select * from ledger where acctno=1;
sqlite>
putting quotes around the 1 above changes nothing.
Interestingly enough, "select * from ledger where acctno > 1" returns results! However since it returns ALL results, it's not terrible useful.
I'm sure someone will ask about the table structure, so here goes:
sqlite> .schema ledger
CREATE TABLE "LEDGER" (
"ACCTNO" integer(10,0) NOT NULL,
"drbal" integer(20,0) NOT NULL,
"crbal" integer(20,0) NOT NULL,
"CURRKEY" char(3,0) NOT NULL,
"TEXTKEY" integer(10,0),
"TEXT" VARCHAR(64,0),
"ACCTYPECD" CHAR(1,0) NOT NULL,
"ACCSTCD" CHAR(1,0),
"PACCTNO" number(10,0) NOT NULL,
"CATCD" number(10,0),
"TRANSNO" number(10,0) NOT NULL,
"extrefno" number(10,0),
"UPDATEUSER" VARCHAR(32,0),
"UPDATEDATE" text(8,0),
"UPDATETIME" TEXT(6,0),
"PAYEECD" number(10,0) NOT NULL,
"drbal2" number(10,0) NOT NULL,
"crbal2" number(10,0) NOT NULL,
"delind" boolean,
PRIMARY KEY("ACCTNO"),
CONSTRAINT "fk_curr" FOREIGN KEY ("CURRKEY") REFERENCES "CURRENCY" ("CUR
RKEY") ON DELETE RESTRICT ON UPDATE CASCADE
);
The strangest thing is that I have other similar tables where this works fine!
sqlite> select * from journalhdr where transno=13;
13|Test transaction ATM Withdrawel 20130213|20130223||20130223||
TransNo in that table is also integer (10,0) NOT NULL - this is what makes me thing it is something to do with the values.
Another clue is that the sort order seems to be based on ascii, not numeric:
sqlite> select * from ledger order by acctno;
0|0|0|JPY|11|Root Account|P|X|0|X|0|0|SYSTEM|20121209|150000|0|0|0|
1|0|0|JPY|8|Paid-In Capital|C|X|0|X|0|0||||0|0|0|
10|0|0|USD|20|Sallie Mae|L|X|0|X|0|0|SYSTEM|20121209|153900|0|0|0|
21|0|0|USD|21|Skrill|A|X|0|X|0|0|SYSTEM|20121209|154000|0|0|0|
22|0|0|USD|22|AES|L|X|0|X|0|0|SYSTEM|20121209|154200|0|0|0|
23|0|0|JPY|23|Marui|L|X|0|X|0|0|SYSTEM|20121209|154400|0|0|0|
24|0|0|JPY|24|Amex JP|L|X|0|X|0|0|SYSTEM|20121209|154500|0|0|0|
3|0|0|JPY|13|Mitsubishi Bank Futsuu|A|X|0|X|0|0|SYSTEM|20121209|150000|0|0|0|
Of course the sort order on journalhdr (where the select works properly) is numeric.
Solved! (sort-of)
The data can be fixed like this:
sqlite> update ledger set acctno = 23 where rowid = 13;
sqlite> select * from ledger where acctno = 25;
25|0|0|JPY|0|Test|L|X|0|X|0|0|SYSTEM|20130224|132500|0|0|0|
Still, if it was stored as strings, then that leave a few questions:
1. Why couldn't I select it as a string using the quotes?
2. How did it get stored as a string since it is a valid integer?
3. How would you go about detecting this problem normally besides noticing bizzarre symptoms?
Although the data would normally be entered by my program, some of it was created by hand using Navicat, so I assume the problem must lie there.
You are victim of SQLite dynamic typing.
Even though SQLite defines system of type affinity, which sets some rules on how input strings or numbers will be converted to actual internal values, but it does NOT prevent software that is using prepared statements to explicitly set any type (and data value) for the column (and this can be different per row!).
This can be shown by this simple example:
CREATE TABLE ledger (acctno INTEGER, name VARCHAR(16));
INSERT INTO ledger VALUES(1, 'John'); -- INTEGER '1'
INSERT INTO ledger VALUES(2 || X'00', 'Zack'); -- BLOB '2\0'
I have inserted second row not as INTEGER, but as binary string containing embedded zero byte. This reproduces your issue exactly, see this SQLFiddle, step by step. You can also execute these commands in sqlite3, you will get the same result.
Below is Perl script that also reproduces this issue
This script creates just 2 rows with acctno having values of integer 1 for first, and "2\0" for second row. "2\0" means string consisting of 2 bytes: first is digit 2, and second is 0 (zero) byte.
Of course, it is very difficult to visually tell "2\0" from just "2", but this is what script below demonstrates:
#!/usr/bin/perl -w
use strict;
use warnings;
use DBI qw(:sql_types);
my $dbh = DBI->connect("dbi:SQLite:test.db") or die DBI::errstr();
$dbh->do("DROP TABLE IF EXISTS ledger");
$dbh->do("CREATE TABLE ledger (acctno INTEGER, name VARCHAR(16))");
my $sth = $dbh->prepare(
"INSERT INTO ledger (acctno, name) VALUES (?, ?)");
$sth->bind_param(1, "1", SQL_INTEGER);
$sth->bind_param(2, "John");
$sth->execute();
$sth->bind_param(1, "2\0", SQL_BLOB);
$sth->bind_param(2, "Zack");
$sth->execute();
$sth = $dbh->prepare(
"SELECT count(*) FROM ledger WHERE acctno = ?");
$sth->bind_param(1, "1");
$sth->execute();
my ($num1) = $sth->fetchrow_array();
print "Number of rows matching id '1' is $num1\n";
$sth->bind_param(1, "2");
$sth->execute();
my ($num2) = $sth->fetchrow_array();
print "Number of rows matching id '2' is $num2\n";
$sth->bind_param(1, "2\0", SQL_BLOB);
$sth->execute();
my ($num3) = $sth->fetchrow_array();
print "Number of rows matching id '2<0>' is $num3\n";
Output of this script is:
Number of rows matching id '1' is 1
Number of rows matching id '2' is 0
Number of rows matching id '2<0>' is 1
If you were to look at resultant table using any SQLite tool (including sqlite3), it will print 2 for second row - they all get confused by trailing 0 inside a BLOB when it gets coerced to string or number.
Note that I had to use custom param binding to coerce type to BLOB and permit null bytes stored:
$sth->bind_param(1, "2\0", SQL_BLOB);
Long story short, it is either some of your client programs, or some of client tools like Navicat which screwed it up.
I am using asp.net2008 and MY SQL.
I want to auto-generate the value for the field username with the format as
"SISI001", "SISI002",
etc. in SQL whenever the new record is going to inserted.
How can i do it?
What can be the SQL query ?
Thanks.
Add a column with auto increment integer data type
Then get the maximum value of that column in the table using "Max()" function and assign the value to a integer variable (let the variable be 'x').
After that
string userid = "SISI";
x=x+1;
string count = new string('0',6-x.ToString().length);
userid=userid+count+x.ToString();
Use userid as your username
Hope It Helps. Good Luck.
PLAN A>
You need to keep a table (keys) that contains the last numeric ID generated for various entities. This case the entity is "user". So the table will contain two cols viz. entity varchar(100) and lastid int.
You can then have a function written that will receive the entity name and return the incremented ID. Use this ID concatenated with the string component "SISI" to be passed to MySQL for insertion to the database.
Following is the MySQL Table tblkeys:
CREATE TABLE `tblkeys` (
`entity` varchar(100) NOT NULL,
`lastid` int(11) NOT NULL,
PRIMARY KEY (`entity`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
The MySQL Function:
DELIMITER $$
CREATE FUNCTION `getkey`( ps_entity VARCHAR(100)) RETURNS INT(11)
BEGIN
DECLARE ll_lastid INT;
UPDATE tblkeys SET lastid = lastid+1 WHERE tblkeys.entity = ps_entity;
SELECT tblkeys.lastid INTO ll_lastid FROM tblkeys WHERE tblkeys.entity = ps_entity;
RETURN ll_lastid;
END$$
DELIMITER ;
The sample function call:
SELECT getkey('user')
Sample Insert command:
insert into users(username, password) values ('SISI'+getkey('user'), '$password')
Plan B>
This way the ID will be a bit larger but will not require any extra table. Use the following SQL to get a new unique ID:
SELECT ROUND(NOW() + 0)
You can pass it as part of the insert command and concatenate it with the string component of "SISI".
I am not an asp.net developer but i can help you
You can do something like this...
create a sequence in your mysql database as-
CREATE SEQUENCE "Database_name"."SEQUENCE1" MINVALUE 1 MAXVALUE 9999999999999999999999999999 INCREMENT BY 001 START WITH 21 CACHE 20 NOORDER NOCYCLE ;
and then while inserting use this query-----
insert into testing (userName) values(concat('SISI', sequence1.nextval))
may it help you in your doubt...
Try this:
CREATE TABLE Users (
IDs int NOT NULL IDENTITY (1, 1),
USERNAME AS 'SISI' + RIGHT('000000000' + CAST(IDs as varchar(10)), 4), --//getting uniqueness of IDs field
Address varchar(150)
)
(not tested)
I am saving documents to database, each document has to have an id with the format YYYY-00000:
the first 4 characters are the current year
the second five characters are numbers. They start with 1 each year and then increment.
For example I could have these documents in my database: 2011-00001, 2011-00002, 2011-00003, 2012-00001, 2012-00002, ...
I am thinking something like this:
add two columns to table Documents (Year and Number)
Year is computed column, something like year(getdate())
Number is computed column, which gets value from a function GetNextNumberForCurrentYear
GetNextNumberForCurrentYear returns next number for the current year (for example select max(Number) + 1 from Documents where Year = year(getdate()), and some isnull checking)
But i fear, that two users could want to save the document at the same time and that they would receive the same Number. Is this possible? Any better ideas?
It is a ASP.NET C# web application, .NET 4.0, MSSQL 2005, I have the control over all the parts of the application.
PS: after insert I would like to return the Id of the new document to the user, so I would probably have to do something like: select Id from Documents where SomeId = scope_identity(), so I guess there should be an identity column somewhere...?
Edit (final solution): I get the next number from stored procedure, build the Id of the document (in format YYYY-00001) in .NET, save the whole document to the database (using TransactionScope for whole process) and then return the Id to the user.
create table DocumentNumbers ([Year] int not null, Number int not null default 1)
insert into DocumentNumbers ([Year], Number)
select 2012, 1 -- and more...
create procedure GetNextDocumentNumber
#year int
as
begin
declare #myResult table (nextNumber int)
update DocumentNumbers
set Number = isnull(Number, 0) + 1
output inserted.Number into #myResult
where [Year] = #year
select top 1 nextNumber from #myResult
end
You could create a table NumberSeries, which contains a column Year and a column CurrentNo and a function that returns the next number from it like the following:
DECLARE #myResult TABLE (nextNumber INT)
UPDATE NumberSeries
OUTPUT INSERTED.NextNo INTO #myResult
SET
CurrentNo = ISNULL(CurrentNo, 0) + 1
WHERE
Year = Year(GetDate())
DECLARE #result INT
#result = (SELECT TOP 1 nextNumber FROM #myResult)
RETURN #result
This updates the NumberSeries table atomically and inserts the new value into the #myResult table variable. After that, it returns the first (and only) value from the #myResult table variable.
Everything else, like SCOPE_IDENTITY() and such may cause errors when using triggers or in other cases - the solution using the OUTPUT clause is safe.
EDIT
As for returning the ID of the inserted document: this is basically the same thing.
DECLARE #myDocId TABLE (yr int, no int)
INSERT INTO Documents
OUTPUT INSERTED.Year , INSERTED.YearID INTO #myDocID
...
SELECT TOP 1
CAST(yr AS NVARCHAR) +
'_' +
RIGHT(REPLICATE('0', 5) + CAST(no AS NVARCHAR), 5) AS NewID
This is my table where i want my PNRNo to be generated as 'PNRRES001' for the first entry, and consecutive entries with 'PNRRES002','PNRRES002' so on.
So while creating table only i called that column to function which will generate the PNR no, User just has to enter the CustomerNo from the front end, and data wit PNR & Customer No will updated to the PNRDetails table.
CREATE TABLE PNRDetails(PNRNo AS (DBO.FuncIncPNR()) ,customerNo INT
--FUNCTION TO GENERATE THE PNR NUMBER
ALTER FUNCTION dbo.FuncIncPNR()
RETURNS VARCHAR(20)
AS
BEGIN
DECLARE #RR VARCHAR(20) SET #RR='PNRRESA001'
--here i have checked if no value is there then return the first value as 'PNRRESA001'
IF((SELECT COUNT(*)FROM PNRDetails)=0)
BEGIN
RETURN #RR
END
ELSE
-- if any value is there then take the last value and add 1 to it and update to the table
BEGIN
DECLARE #pnr VARCHAR(20),#S1 VARCHAR(20),#S2 INT
DECLARE PNRCursor CURSOR Static
FOR SELECT PNRNo FROM PNRDetails
OPEN PNRCursor
FETCH LAST FROM PNRNo INTO #pnr
SET #S1=SUBSTRING(#pnr,1,7)
SET #S2=RIGHT(#PNR,3)
SET #S2=#S2+1;
SET #pnr=#S1+#S2;
END
RETURN #pnr
END
--Here am inserting only customerNo as 5 and the PNR should be generated by my function
INSERT INTO PNRDetails VALUES(5)
--it shows 1 row updated :)
SELECT * FROM PNRDetails
-- but when i run select command it shows
--Maximum stored procedure, function, trigger, or view nesting level exceeded (limit 32). :(
U can run this.And pls do help if u find anything that could help me. any help will be appreciated...
Waiting for your kind response...
You could try to use a computed column and an identity column instead.
create table PNRDetails
(
ID int identity,
PNRNo as 'PNRRES'+right(1000+ID, 3),
customerNo int
)
I would suggest just using an IDENTITY instead as your id, let SQL Server handle the assignment of each id number with all it's built-in guards for concurrency, and leave the formatting up to the UI....or, create a computed column that defines the formatted version of the ID if you really do need it in the DB.
The risk you run with your intended approach is:
poor performance
concurrency issues - if loats of ids are being generate around the same time
If you are happy to change the table structure. Following will do the job.
CREATE TABLE [dbo].[PNRDetails](
[autoId] [int] IDENTITY(1,1) NOT NULL,
[prnNo] AS ('PNRRES'+right('000'+CONVERT([varchar](3),[dbo].[GetRowCount]([autoId]),(0)),(3))),
[customerNo] [int] NOT NULL,
CONSTRAINT [PK_Table1] PRIMARY KEY CLUSTERED
(
[autoId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
EDIT: to address identity issue for your requirement pls create following function and pass the [autoId] in as above (edited) in the computed column.
CREATE FUNCTION dbo.GetRowCount
(
#autoId INT
)
RETURNS INT
AS
BEGIN
DECLARE #RESULTS AS INT
SELECT #RESULTS = COUNT(autoId) FROM PNRDetails WHERE PNRDetails.autoId<#autoId
RETURN #RESULTS + 1
END
GO
--INSERT
INSERT INTO PNRDetails (customerNo) VALUES(5)
1) You can use an identity column in your database (INTEGER)
PROS: easy/No gaps in between generated ids
CONS: You have to select the inserted id & return via procedure/query
if you were to show it to end user
2) Define a database sequence
PROS: easy to implement/Can be stored/shown to user before the form is
even saved
CONS: Gaps in between if the certain id is once generated & not used
3). Select max(id) from column + 1
PROS: Useful where only single user inserts in a table
CONS: disastrous if you were in an environment where multiple users
were inserting in the same tablle (mismatched max ids)
4) Use a database trigger to autoincrement the column
PROS:automated
CONS: hard to debug (you have to make sure it don't breaks for some
reason otherwise insert fails)
Change the way your trigger works. Something like this
CREATE FUNCTION dbo.fn_FuncIncPNR(#ID int)
RETURNS varchar(20)
BEGIN
Declare #Retval varchar(20),
#No varchar(4)
Select #No = convert(varchar(4), #ID)
while Len(#No) < 4
Select #No = '0' + #No
Select #Retval = 'PNRRESA' + #No
RETURN #Retval
END
You will notice there is a parameter field
Change your table create to this
CREATE TABLE PNRDetails(PNRNo AS (dbo.fn_ShowPNRNo(wID)), wID int IDENTITY(1,1) NOT NULL, customerNo INT)
That should solve your problem