I'm trying to get a name by calling a stored procedure.
sql code:
create procedure GetName
#ID int,
#name nvarchar(32) output
as
select #name=name from SalesInfo where ID=#ID
c code
...
SQLRETURN rc;
SQLLEN cbParam = SQL_NTS;
int ID = 1;
wchar_t name[32];
rc = SQLBindParameter(hstmt, 1, SQL_PARAM_INPUT, SQL_C_SLONG, SQL_INTEGER, 0, 0, &ID, 0, NULL);
rc = SQLBindParameter(hstmt, 2, SQL_PARAM_INPUT_OUTPUT, SQL_C_WCHAR, SQL_WCHAR, SQL_DESC_LENGTH, 0, name, sizeof(name), &cbParam);
rc = SQLExecDirect(hstmt, TEXT("{call GetName(?,?)}"), SQL_NTS);
I received a string, but there was an error message, 'string data, right truncation'
The string was padded with blanks, like "name "
you need to increase the size of your nvarchar() so that it doesn't truncate the strings that are larger than 32
increase the size of wchar_t name[N];and #name nvarchar(N) output
Well to get rid of the trim simply use RTRIM(col) AS [col], to determin what length of char vars you need then LEN(Originalcol) or DATALENGTH(Originalcol) http://msdn.microsoft.com/en-us/library/ms173486.aspx in your case to create a proc to see waht actual length you are getting and what you need to define. As its a single var, you wont get much a hit by using NVARCHAR(MAX)
Related
I have a table. There is data in this table and there is a checkbox next to each data. Multiple selection is possible. After the user makes a selection, the id numbers of the selected columns are come in the array. I convert the array to string and send it to the stored procedure and I run the following stored procedure:
Example value for #ResultsIds: 65, 66, 67, 68, 125
#ResultsIds nvarchar(250)
UPDATE MyTable SET [IsVerified] = 1 WHERE Id IN (#ResultsIds)
And I got this error:
Conversion failed when converting the nvarchar value '65, 66, 67, 68, 125' to data type int. Because [Id] column is int data type.
I tried CAST and CONVERT functions of SQL but it didn't work.
SQL Server doesn't do that automatically. Assuming you're on a recent version, you can do this:
declare #ResultsIds nvarchar(250) = '65,66,67,68,125'
UPDATE MyTable
SET [IsVerified] = 1
WHERE Id IN (
select [value]
from string_split(#ResultIDs, ',')
)
declare #ResultsIds nvarchar(250)='65,66,67,68,125'
UPDATE MyTable SET [IsVerified] = 1 WHERE cast(Id as varchar) IN (#ResultsIds)
I solved problem using foreach. I separated the numbers in the string from commas and transferred each number to the array. Then I updated the array one by one by running foreach loop.
public void Verify(DB db, string rows)
{
int[] nums = Array.ConvertAll(rows.Split(','), int.Parse);
foreach (int value in nums)
{
DbCommand cmd = db.GetStoredProcCommand("VerifyProcess");
db.AddInParameter(cmd, "#ResultId", DbType.Int32, value);
db.ExecuteNonQuery(cmd);
}
}
I have a stored procedure:
ALTER PROCEDURE [dbo].[spUpdateOrInsertNotification]
#ContentJsonHash BINARY(32)
AS
DECLARE #NotificationId INT;
SET #NotificationId = (SELECT #NotificationId
FROM dbo.tblNotifications n
WHERE n.ContentJsonHash = #ContentJsonHash);
IF #NotificationId IS NOT NULL
BEGIN
-- Increment Count
END
ELSE
BEGIN
-- Insert new row.
END
It's supposed to check if the Hash already exists and if it does, increment the count for the row, otherwise insert the row. However, it never finds the Hash and the corresponding NotificationId. NotificationId is always null.
If I run it twice, passing it the same data (a C# array byte[32]). It never finds the same NotificationId and I end up with duplicate entries being put in.
e.g.
NotificationId | ContentJsonHash
9 0xB966C33517993003D789EDF78DA20C4C491617F8F42F76F48E572ACF8EDFAC2A
10 0xB966C33517993003D789EDF78DA20C4C491617F8F42F76F48E572ACF8EDFAC2A
Can I not do comparisons on Binary(n) fields like this WHERE n.ContentJsonHash = #ContentJsonhash ?
The C# code:
using (var conn = new SqlConnection(Sql.ConnectionString))
{
await conn.OpenAsync();
using (var cmd = new SqlCommand(Sql.SqlUpdateOrInsertNotification, conn))
{
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.AddWithValue("#Source", notificationMessage.Source);
cmd.Parameters.AddWithValue("#Sender", notificationMessage.Sender);
cmd.Parameters.AddWithValue("#NotificationType", notificationMessage.NotificationType);
cmd.Parameters.AddWithValue("#ReceivedTimestamp", notificationMessage.Timestamp);
cmd.Parameters.AddWithValue("#ContentJSon", notificationMessage.NotificationContent);
cmd.Parameters.AddWithValue("#ContentJsonHash", notificationMessage.ContentHashBytes);
await cmd.ExecuteNonQueryAsync();
}
}
I've also tried calling the stored procedure from SQL like this:
exec dbo.spUpdateOrInsertNotification 'foo', 'bar', 0,
'2017-12-05 15:23:41.207', '{}',
0xB966C33517993003D789EDF78DA20C4C491617F8F42F76F48E572ACF8EDFAC2A
Calling this twice returns 2 rows :(
I can do this, which works, hard coding the binary field I want to check
select *
from dbo.tblNotifications
where ContentJsonhash = 0xB966C33517993003D789EDF78DA20C4C491617F8F42F76F48E572ACF8EDFAC2A
Binary comparisons can be tricky. If you are using a true binary column, I believe length also comes into play. So even if those bytes are the same, and the lengths differ, the comparison would be false. An easy way is to convert these to strings:
alter procedure [dbo].[spUpdateOrInsertNotification]
#ContentJsonHash BINARY(32)
AS
DECLARE #NotificationId INT;
SET #NotificationId = (SELECT NotificationId
FROM dbo.tblNotifications n
WHERE convert(varchar(32), n.ContentJsonHash, 2) = convert(varchar(32), #ContentJsonHash, 2));
IF #NotificationId IS NOT NULL
BEGIN
-- Increment Count
END
ELSE
BEGIN
-- Insert new row.
END
I had an # where I shouldn't have had an ampersand.
SET #NotificationId = (SELECT #NotificationId
FROM dbo.tblNotifications n
WHERE convert(varchar(32), n.ContentJsonHash, 2) = convert(varchar(32), #ContentJsonHash, 2));
Should be
SET #NotificationId = (SELECT NotificationId
FROM dbo.tblNotifications n
WHERE convert(varchar(32), n.ContentJsonHash, 2) = convert(varchar(32), #ContentJsonHash, 2));
I feel so stupid for not noticing this sooner :(
We are trying to insert a large string into a table column and getting an error "length can't exceed maximum length(8388607 bytes)". (0x7F FFFF). The input data field length exceeds 10MB.
HANA version SPS 9 (Rev 97)
Data type of variable and table column is CLOB
Using INSERT in a SQLSCRIPT Stored Procedure
The HANA data types documentation say that maximum length of any LOB object is 2GB (0x7FFF FFFF). Our string length is well within this limit. So this is very confounding. Will appreciate any hints to resolve this.
Thanks a lot.
---------- CODE
CREATE PROCEDURE XXX_SCHEMA.PROC_INSERT_INTO_CLOB
( IN DATA_CLOB CLOB, )
BEGIN
LANGUAGE SQLSCRIPT SQL SECURITY INVOKER default schema XXX_SCHEMA AS
INSERT INTO "XXX_SCHEMA"."XXX::DB_YY_CLOB"
(
'ABC' ,
CURRENT_TIMESTAMP ,
DATA_CLOB
)
SELECT F1,
F2,
:DATA_CLOB
FROM DUMMY ;
END;
-- Table Defintion
table.schemaName = "XXX_SCHEMA";
table.tableType = ROWSTORE;
table.columns = [
{name = "F1";sqlType = NVARCHAR;nullable = false; length = 3;},
{name = "F2";sqlType = TIMESTAMP;nullable = true;},
{name = "DATA_CLOB";sqlType = CLOB;nullable = true;}];
The reason for the error is that you seem to use string methods to deal with the CLOB data.
When I tried simple things like inserting a really long value generated via
update rclob set data_clob = lpad ('X', 2000000000, 'Y');
I also received the error message
Could not execute 'update rclob set data_clob = lpad ('X', 2000000000, 'Y')'
SAP DBTech JDBC: [384]: string is too long: length can't exceed maximum length(8388607bytes) at function lpad() (at pos 29)
Since LPAD produces a string before it gets entered into the CLOB, the error message is thrown before the CLOB column is actually touched.
Generally LOB columns can only be inserted by binding the data to a parameter in the insert statement.
In DB2 9.7 I am looking for a way to reverse a string in a SQL query.
I am familiar with SQL Server where the query would be like
SELECT
REVERSE(LEFT_TO_REIGHT) AS RIGHT_TO_LEFT
FROM
TABLE1;
I couldn't find a similar function in DB2. is there a simple way to reverse a string?
Creating a REVERSE(..) function is unnecessary.
DB2 has something called RIGHT(string-expression, length):
The RIGHT function returns the rightmost string of string-expression
of length length, expressed in the specified string unit. If
string-expression is a character string, the result is a character
string. If string-expression is a graphic string, the result is a
graphic string
So if you're interested in the last 8 characters, you can pretty trivially do this via:
SELECT RIGHT(left_to_right, 8) AS right_to_left
FROM Table1
(I'm actually still concerned about the fact that you're splitting off 8 characters consistently, as it implies you have a multi-part key of some sort).
Try something like:
SELECT STRIP(CAST( TRANSLATE('87654321',LEFT_TO_REIGHT, '12345678') AS VARCHAR(8) ))
FROM TABLE1;
Due to the original question this is the first webpage that comes up when one searches for 'How to reverse a string in DB2'.
Here is an answer that doesn't require implementing it in C and shouldn't brake on non-pure-Engilsh strings regardless of their length.
Be warned though, the efficiency is 'meh' at best.
CREATE FUNCTION REVERSE_STRING(STR VARCHAR(100))
RETURNS VARCHAR(100)
LANGUAGE SQL
SPECIFIC REVERSE_STRING
DETERMINISTIC
REVERSE: BEGIN
DECLARE REVERSED_STRING VARCHAR(100);
DECLARE REVERSED_CHARACTERS_INDEX INTEGER;
SET REVERSED_STRING='';
SET REVERSED_CHARACTERS_INDEX=0;
WHILE (REVERSED_CHARACTERS_INDEX < CHARACTER_LENGTH(STR, CODEUNITS16))
DO
SET REVERSED_CHARACTERS_INDEX = REVERSED_CHARACTERS_INDEX + 1;
SET REVERSED_STRING = CONCAT(
REVERSED_STRING,
LEFT(RIGHT(STR, REVERSED_CHARACTERS_INDEX, CODEUNITS16), 1, CODEUNITS16));
END WHILE;
RETURN REVERSED_STRING;
END REVERSE#
The idea is to get a substring which starts from the n-th character from the right till the end of the string, then take the first element of this substring from the left and append it to a reversed string. This operation is conducted n times where n is the length of a string to be reversed.
You can use it like any other function.
SELECT FIRSTNME AS FIRSTNAME, REVERSE_STRING(FIRSTNME) AS REVERSED_FIRSTNAME
FROM SAMPLE.EMPLOYEE#
Example output
Answering the original question of reversing a string there's user defined functions published on the IBM site that will do it that you can find here. There's apparently no built in ability in DB2
https://www.ibm.com/developerworks/community/blogs/SQLTips4DB2LUW/entry/reverse?lang=en
Tortured SQL version:
CREATE OR REPLACE FUNCTION REVERSE(INSTR VARCHAR(4000))
RETURNS VARCHAR(4000) SPECIFIC REVERSE
DETERMINISTIC NO EXTERNAL ACTION CONTAINS SQL
RETURN WITH rec(pos, res) AS (VALUES (1, CAST('' AS VARCHAR(4000)))
UNION ALL
SELECT pos + 1, SUBSTR(INSTR, pos , 1) || res
FROM rec
WHERE pos <= LENGTH(INSTR)
AND pos < 5000)
SELECT res FROM rec WHERE pos > LENGTH(INSTR);
But then you have to do this as well, yuck:
CREATE BUFFERPOOL bp32 PAGESIZE 32K;
CREATE SYSTEM TEMPORARY TABLESPACE tsp32 PAGESIZE 32K BUFFERPOOL bp32;
A saner C implementation
#include <sqludf.h>
#ifdef __cplusplus
extern "C"
#endif
void SQL_API_FN ReverseSBCP(SQLUDF_VARCHAR *inVarchar,
SQLUDF_VARCHAR *outVarchar,
SQLUDF_SMALLINT *inVarcharNullInd,
SQLUDF_SMALLINT *outVarcharNullInd,
SQLUDF_TRAIL_ARGS)
{
int inLen, inPos, outPos;
if (*inVarcharNullInd == -1)
{
*outVarcharNullInd = -1;
}
else
{
inLen = strlen(inVarchar);
for (inPos = 0, outPos = inLen -1; inPos < inLen; inPos++, outPos--)
{
outVarchar[outPos] = inVarchar[inPos];
}
outVarchar[inLen] = '\0';
*outVarcharNullInd = 0;
}
return;
}
I have written following piece of code in C:
EXEC SQL begin declare section;
int A;
char B[5];
int C;
int D;
dtime_t E;
char F[13];
EXEC SQL END DECLARE SECTION;
char E_dt[16];
D=0;
memset(F, 0, sizeof(F));
EXEC SQL declare log3 cursor for select A, B, C, D, E, F from tbl WHERE C=123;
if(sqlca.sqlcode)
{
return;
}
EXEC SQL fetch log3
into
:A, :B, :C, :D, :E, :F,
if(sqlca.sqlcode)
{
if (sqlca.sqlcode != DB_NORECORDS)
{
return;
}
break;
}
When we run this piece of code, where the value of F is Null in the table tbl. It gives error code 1405. I have tried memset function for setting its default value as 0. But it did not work. And one more thing can i fetch more than 90 field at a time, when i was trying to do that it gives me Bus Error at the time of compilation. Thanks in advance please help me out.
You have 2 basic options:
Use an indicator to record the presence of the NULL. You probably should use this option when you want a specific action to be taken when a NULL arises.
Use the NVL function to convert the retrieved NULL to another value, such as zero or blank. This is the simplest solution.
Edit:
Example with NVL for log3 cursor. Choose whatever default values you want. In the example I have used ' ' for character fields, 0 for numeric fields and Jan 1st year 1 for dates.
EXEC SQL declare log3 cursor for select NVL(A, 0),
NVL(B, ' '),
NVL(C, 0),
NVL(D, 0),
NVL(E, to_date('0001', 'YYYY')),
NVL(F, ' ')
from tbl
WHERE C=123;