looping through recordset in stored procedure - sql

Question

I have created a tbl having SELECT statement as value (fieldname sqltxt).
Now want to read rows one by one and execute all the select statement stored in this table.
If it does not return any row i.e. zero row
insert a new record in DMSResults with value of DOCID from DMSRec
For that I use following script
set nocount on
use TESTDB
declare #sqlTXT as varchar(max);
DECLARE #DocID nvarchar(30);
drop table DMSResults
CREATE TABLE DMSResults (DOCID nvarchar(30) );`
drop table DMSRec
SELECT .....intoDMSRec FROM tbl....
Above syntax is a Big SQl script to create a recordset.
For my conveyance I insert all the records into new tbl.
Its returns more than 10,00,000 records
Now want to loop in tbl DMSREC, read the value of field sqltxt
Execute that statement.
If it doesn't return a record
Insert a record in DMSResults with value of DOCID field.
I also tried with following commands, but do not know how to loop in sql for next rec until eof and exit
Since DMSRec is a temporary table, once a row is processed then we can remove record from DMSRec.
declare #rc as bigint
Select #rc = Row_Count
From sys.dm_db_partition_stats
Where Object_Name(Object_Id) = 'DMSRec'
WHILE #rc <1
BEGIN
exec(select sqltxt from dmsrec where row=1)
-- here check record is exist or not then
-- if it is not exist or returning zero
-- add record in dmsresult with docid value
-- delete dmsrec where row=1
-- loop for next
END
Considering the huge size of database SQL-Server 2008r2 please guide me any optimize solution.
DMSRec TBL recordset.
DOCID         SQLTXT
A01/17-18     SELECT VRNO FROM TBL_LET WHERE VRNO='A01/17-18'

Answer 1

I can't address the actual problem here, but I can elaborate on the question of how to loop through all records. BTW< loops are terrible for performance and thus are avoided at all costs in SQL Server.
--get the row count of the table
declare #rc as bigint
Select #rc = (select count(*) from DMSRec)
--variables for incrementing rows and storing SQL
declare #i bigint = 1
declare #sql varchar(max)
WHILE #i <= #rc
BEGIN
--get the SQL Statement from the table
set #sql = (select sqltxt from dmsrec where row=#i)
--If no value was returned, insert into DSMResults
if (#sql is null) or (ltrim(rtrim(#sql)) = '')
begin
insert into DMSResults
select DOCID from dmsrec
end
--If a value was returned, execute that statement
else
begin
exec(#sql)
end
--increment the row number
set #i = #i + 1
END