SQL - update field if greater than 500 - sql

I have the following procedure:
CREATE PROCEDURE alterFieldSize #column NVARCHAR(MAX), #table NVARCHAR(MAX), #prsColumnLen INT
AS
-- DECLARE VARIABLES
DECLARE #sql NVARCHAR(MAX)
DECLARE #fieldLen INT
DECLARE #columnLen INT
-- SET VARIABLES
SET #fieldLen = #prsColumnLen
SET #columnLen = (SELECT CHARACTER_MAXIMUM_LENGTH FROM INFORMATION_SCHEMA.COLUMNS WHERE COLUMN_NAME LIKE #column AND TABLE_NAME LIKE #table)
SET #fieldLen = CASE WHEN #columnLen > #fieldLen THEN #columnLen WHEN #fieldLen <=500 THEN #fieldLen ELSE 500 END
SET #sql = 'ALTER TABLE Client ALTER COLUMN '+ #column + ' NVARCHAR('+cast(#fieldLen as VARCHAR(20))+')'
-- Execution
EXEC(#sql)
Which is then called via:
SET #fieldLen = (SELECT MAX(LEN(s.StreetAddress)) FROM [DB1].dbo.Sites s)
EXEC alterFieldSize #column = 'ClientAddress', #table = 'Client', #prsColumnLen = #fieldLen
Ofcourse this runs into issues because if the field values are set to 500 then i cant insert the data accross due to the field being too small in size unless i do this manually on each insert statement. What i want is to take everything after the 500th character out if the field is set to 500 during that case.
Thanks in advance

Variant 1: create new persisted computed column with maximal lenght of 500
alter table add NewPersistedColumn as (left(YourColumn, 500) persisted
Variant 2: make instead of insert trigger with left function
create trigger trg_table on trg_table
instead of insert
as
insert into table (col, col2) select left(col, 500), col2 from inserted.*
Best solution is to avoid this string in your app. Your solution should depend on your purpose of longer and shorter field.

Related

View without null columns

Is there a way to create a view of a table without the columns that are null.
What i mean by that is that i want a view where there are only columns where at least one row has some data in that column and is not empty.
In this example, the result would be a view with columns A and C
I'm using Microsoft SQL and the data in db aren't going to be updated.
That is not possible via the view, because the view cannot handle the dynamic column set. It is possible only via the stored procedure returning the result set. I made not a very beautiful and not generic decision, but I think you can upgrade it if you can.
First, we need to create a function which returns the set of columns which have at least one non-null value:
create function getTheColumnList() returns nvarchar(max) as
begin
declare #columnlist nvarchar(max);
set #columnlist = ''
declare #totalrows int;
set #totalrows = (select
count(*)
from table_name)
if (select
count(*)
from table_name
where A is null) < #totalrows
set #columnlist = #columnlist + 'A, '
if (select
count(*)
from table_name
where B is null) < #totalrows
set #columnlist = #columnlist + 'B, '
if (select
count(*)
from table_name
where C is null) < #totalrows
set #columnlist = #columnlist + 'C, '
set #columnlist = replace(#columnlist + '%', ', %', '')
return #columnlist;
end
go
Then we need to use this function in a dynamic SQL to construct the needed query. It can be done inside the stored procedure:
create proc getNottNullFromTableName as
declare #SQL nvarchar(1000)
declare #columnist varchar(50)
set #columnist = dbo.getTheColumnList();
set #SQL = 'SELECT ' + #columnist + ' FROM table_name';
exec (#SQL)
go
Finally, invoke that procedure:

How to get table from EXEC sp_executesql in #TempTable, within a stored procedure

I need some help
My goal:
I have a #query in a stored procedure which is working perfectly. Now I have to perform more operation on the returning table from #query execution within same stored procedure. e.g I have to add more columns in the returning table and add new data from more queries.
My problem:
I am not able to get returning table form (EXEC sp_executesql) into a variable (#TempTable). And one more problem is that the number of columns returning are not known (dynamic).
Steps should be like this:
Declare TempTable
TempTable = EXEC sq_executesql
Add new columns to TempTable
Fill more data
Kindly guide me
this can be achieved using global temp tables like below :
DECLARE #sql NVARCHAR(1000)
DECLARE #Column NVARCHAR(1000)
SET #Column = 'YouColumnList' -- id,name etc. created by you dynamically.
IF( Object_id('tempdb..##IntermediateTable') IS NOT NULL )
DROP TABLE ##IntermediateTable
SET #sql = '
SELECT ' + #Column + '
Into ##IntermediateTable
FROM YourTable
WHERE id = 123
'
EXEC sp_executesql
#sql
IF( Object_id('tempdb..#temptable') IS NOT NULL )
DROP TABLE #temptable
SELECT *
INTO #temptable
FROM ##IntermediateTable
IF( Object_id('tempdb..##IntermediateTable') IS NOT NULL )
DROP TABLE ##IntermediateTable
SELECT *
FROM #temptable --resulting temptable to use. alter it or do whatever desired.

How to store a dynamic SQL result in a variable in T-SQL?

I have a stored procedure which takes 'table name' as parameter. I want to store my 'exec' results to a variable and display using that variable.
Here is my T-SQL stored procedure..
create procedure DisplayTable( #tab varchar(30))
as
begin
Declare #Query VARCHAR(30)
set #Query='select * from ' +#tab
EXEC (#Query)
END
I want to do something like this..
SET #QueryResult = EXEC (#Query)
select #QueryResult
How do i achieve this.. Please help.. I am a beginner..
You can use XML for that. Just add e.g. "FOR XML AUTO" at the end of your SELECT. It's not tabular format, but at least it fulfills your requirement, and allows you to query and even update the result. XML support in SQL Server is very strong, just make yourself acquainted with the topic. You can start here: http://technet.microsoft.com/en-us/library/ms178107.aspx
alter procedure DisplayTable(
#tab varchar(30)
,#query varchar(max) output
)
as
BEGIN
Declare #execution varchar(max) = 'select * from ' +#tab
declare #tempStructure as table (
pk_id int identity
,ColumnName varchar(max)
,ColumnDataType varchar(max)
)
insert into
#tempStructure
select
COLUMN_NAME
,DATA_TYPE
from
INFORMATION_SCHEMA.columns
where TABLE_NAME= #tab
EXEC(#execution)
declare #ColumnCount int = (SELECT count(*) from #tempStructure)
declare #counter int = 1
while #counter <= #ColumnCount
BEGIN
IF #counter = 1
BEGIN
set #query = (SELECT ColumnName + ' ' + ColumnDataType FROM #tempStructure where pk_id= #counter)
END
IF #counter <> 1
BEGIN
set #query = #query + (SELECT ',' + ColumnName + ' ' + ColumnDataType FROM #tempStructure where #counter = pk_id)
END
set #counter = #counter + 1
END
END
When you execute the SP, you'll now get a return of the structure of the table you want.
This should hopefully get you moving.
If you want the table CONTENTS included, create yourself a loop for the entries, and append them to the #query parameter.
Remember to delimit the #query, else when you read it later on, you will not be able to restructure your table.
First of all you have to understand that you can't just store the value of a SELECTon a table in simple variable. It has to be TABLE variable which can store the value of a SELECTquery.
Try the below:
select 'name1' name, 12 age
into MyTable
union select 'name2', 15 union
select 'name3', 19
--declaring the table variable and selecting out of it..
declare #QueryResult table(name varchar(30), age int)
insert #QueryResult exec DisplayTable 'MyTable'
select * from #QueryResult
Hope this helps!

How to use a variable in an Sybase update statement

This query is to prove a concept that I will eventually use to locate all columns with a specific value and then create a name/value pair for export to JSON. But I'm stuck.
I query the list of all columns from the sql table. I would then like to go through the columns in Table1 row by row and update the values using the variable to construct the query. For example as it reads through the list if Col4 = "Old text" then I would like to set the value of Col 4 = "New Text"
DECLARE #c varCHAR(100)
DECLARE ReadData CURSOR
FOR SELECT cname FROM sys.syscolumns WHERE creator = 'dbserver' AND tname = 'Table1'
DECLARE #RowCount INT
SET #RowCount = (SELECT COUNT(cname) FROM sys.syscolumns WHERE creator = 'dbserver' AND tname = 'Table1')
OPEN ReadData
DECLARE #I INT // iterator
SET #I = 1 // initialize
WHILE (#I <= #RowCount)
BEGIN
FETCH NEXT ReadData INTO #c
INSERT INTO serverdb.Table2 (cname)VALUES(#c)// this works inserting all 100 columns in the cname column of Table 2
UPDATE serverdb.Table1 SET #c = 'New text' WHERE #c = 'Old text'// this fails with a syntax error. #c is not being interpreted for the query. Note: If I hard code the #c var (for testing)to a known column name, the query works as well
SET #I = #I + 1
END;
Why won't the update statement recognize the variable? What am I missing?
When you use varibale as mentioned below it is considered as a character string.
UPDATE serverdb.Table1 SET #c = 'New text' WHERE #c = 'Old text'
You need to create a dynamic query. use the execute method to execute your dynamic query
declare #sql varchar(999)
SELECT #sql = 'UPDATE serverdb.Table1 SET '+ #c + '= ''New text'' WHERE '+ #c+ ' = ''Old text'' '
execute(#sql)
Hope this helps

How to use table variable in a dynamic sql statement?

In my stored procedure I declared two table variables on top of my procedure. Now I am trying to use that table variable within a dynamic sql statement but I get this error at the time of execution of that procedure. I am using Sql Server 2008.
This is how my query looks like,
set #col_name = 'Assoc_Item_'
+ Convert(nvarchar(2), #curr_row1);
set #sqlstat = 'update #RelPro set '
+ #col_name
+ ' = (Select relsku From #TSku Where tid = '
+ Convert(nvarchar(2), #curr_row1) + ') Where RowID = '
+ Convert(nvarchar(2), #curr_row);
Exec(#sqlstat);
And I get the following errors,
Must declare the table variable "#RelPro".
Must declare the table variable "#TSku".
I have tried to take the table outside of the string block of dynamic query but to no avail.
On SQL Server 2008+ it is possible to use Table Valued Parameters to pass in a table variable to a dynamic SQL statement as long as you don't need to update the values in the table itself.
So from the code you posted you could use this approach for #TSku but not for #RelPro
Example syntax below.
CREATE TYPE MyTable AS TABLE
(
Foo int,
Bar int
);
GO
DECLARE #T AS MyTable;
INSERT INTO #T VALUES (1,2), (2,3)
SELECT *,
sys.fn_PhysLocFormatter(%%physloc%%) AS [physloc]
FROM #T
EXEC sp_executesql
N'SELECT *,
sys.fn_PhysLocFormatter(%%physloc%%) AS [physloc]
FROM #T',
N'#T MyTable READONLY',
#T=#T
The physloc column is included just to demonstrate that the table variable referenced in the child scope is definitely the same one as the outer scope rather than a copy.
Your EXEC executes in a different context, therefore it is not aware of any variables that have been declared in your original context. You should be able to use a temp table instead of a table variable as shown in the simple demo below.
create table #t (id int)
declare #value nchar(1)
set #value = N'1'
declare #sql nvarchar(max)
set #sql = N'insert into #t (id) values (' + #value + N')'
exec (#sql)
select * from #t
drop table #t
You don't have to use dynamic SQL
update
R
set
Assoc_Item_1 = CASE WHEN #curr_row = 1 THEN foo.relsku ELSE Assoc_Item_1 END,
Assoc_Item_2 = CASE WHEN #curr_row = 2 THEN foo.relsku ELSE Assoc_Item_2 END,
Assoc_Item_3 = CASE WHEN #curr_row = 3 THEN foo.relsku ELSE Assoc_Item_3 END,
Assoc_Item_4 = CASE WHEN #curr_row = 4 THEN foo.relsku ELSE Assoc_Item_4 END,
Assoc_Item_5 = CASE WHEN #curr_row = 5 THEN foo.relsku ELSE Assoc_Item_5 END,
...
from
(Select relsku From #TSku Where tid = #curr_row1) foo
CROSS JOIN
#RelPro R
Where
R.RowID = #curr_row;
You can't do this because the table variables are out of scope.
You would have to declare the table variable inside the dynamic SQL statement or create temporary tables.
I would suggest you read this excellent article on dynamic SQL.
http://www.sommarskog.se/dynamic_sql.html
Well, I figured out the way and thought to share with the people out there who might run into the same problem.
Let me start with the problem I had been facing,
I had been trying to execute a Dynamic Sql Statement that used two temporary tables I declared at the top of my stored procedure, but because that dynamic sql statment created a new scope, I couldn't use the temporary tables.
Solution:
I simply changed them to Global Temporary Variables and they worked.
Find my stored procedure underneath.
CREATE PROCEDURE RAFCustom_Room_GetRelatedProducts
-- Add the parameters for the stored procedure here
#PRODUCT_SKU nvarchar(15) = Null
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;
IF OBJECT_ID('tempdb..##RelPro', 'U') IS NOT NULL
BEGIN
DROP TABLE ##RelPro
END
Create Table ##RelPro
(
RowID int identity(1,1),
ID int,
Item_Name nvarchar(max),
SKU nvarchar(max),
Vendor nvarchar(max),
Product_Img_180 nvarchar(max),
rpGroup int,
Assoc_Item_1 nvarchar(max),
Assoc_Item_2 nvarchar(max),
Assoc_Item_3 nvarchar(max),
Assoc_Item_4 nvarchar(max),
Assoc_Item_5 nvarchar(max),
Assoc_Item_6 nvarchar(max),
Assoc_Item_7 nvarchar(max),
Assoc_Item_8 nvarchar(max),
Assoc_Item_9 nvarchar(max),
Assoc_Item_10 nvarchar(max)
);
Begin
Insert ##RelPro(ID, Item_Name, SKU, Vendor, Product_Img_180, rpGroup)
Select distinct zp.ProductID, zp.Name, zp.SKU,
(Select m.Name From ZNodeManufacturer m(nolock) Where m.ManufacturerID = zp.ManufacturerID),
'http://s0001.server.com/is/sw11/DG/' +
(Select m.Custom1 From ZNodeManufacturer m(nolock) Where m.ManufacturerID = zp.ManufacturerID) +
'_' + zp.SKU + '_3?$SC_3243$', ep.RoomID
From Product zp(nolock) Inner Join RF_ExtendedProduct ep(nolock) On ep.ProductID = zp.ProductID
Where zp.ActiveInd = 1 And SUBSTRING(zp.SKU, 1, 2) <> 'GC' AND zp.Name <> 'PLATINUM' AND zp.SKU = (Case When #PRODUCT_SKU Is Not Null Then #PRODUCT_SKU Else zp.SKU End)
End
declare #curr_row int = 0,
#tot_rows int= 0,
#sku nvarchar(15) = null;
IF OBJECT_ID('tempdb..##TSku', 'U') IS NOT NULL
BEGIN
DROP TABLE ##TSku
END
Create Table ##TSku (tid int identity(1,1), relsku nvarchar(15));
Select #curr_row = (Select MIN(RowId) From ##RelPro);
Select #tot_rows = (Select MAX(RowId) From ##RelPro);
while #curr_row <= #tot_rows
Begin
select #sku = SKU from ##RelPro where RowID = #curr_row;
truncate table ##TSku;
Insert ##TSku(relsku)
Select distinct top(10) tzp.SKU From Product tzp(nolock) INNER JOIN
[INTRANET].raf_FocusAssociatedItem assoc(nolock) ON assoc.associatedItemID = tzp.SKU
Where (assoc.isActive=1) And (tzp.ActiveInd = 1) AND (assoc.productID = #sku)
declare #curr_row1 int = (Select Min(tid) From ##TSku),
#tot_rows1 int = (Select Max(tid) From ##TSku);
If(#tot_rows1 <> 0)
Begin
While #curr_row1 <= #tot_rows1
Begin
declare #col_name nvarchar(15) = null,
#sqlstat nvarchar(500) = null;
set #col_name = 'Assoc_Item_' + Convert(nvarchar(2), #curr_row1);
set #sqlstat = 'update ##RelPro set ' + #col_name + ' = (Select relsku From ##TSku Where tid = ' + Convert(nvarchar(2), #curr_row1) + ') Where RowID = ' + Convert(nvarchar(2), #curr_row);
Exec(#sqlstat);
set #curr_row1 = #curr_row1 + 1;
End
End
set #curr_row = #curr_row + 1;
End
Select * From ##RelPro;
END
GO
I don't think that is possible (though refer to the update below); as far as I know a table variable only exists within the scope that declared it. You can, however, use a temp table (use the create table syntax and prefix your table name with the # symbol), and that will be accessible within both the scope that creates it and the scope of your dynamic statement.
UPDATE: Refer to Martin Smith's answer for how to use a table-valued parameter to pass a table variable in to a dynamic SQL statement. Also note the limitation mentioned: table-valued parameters are read-only.
Here is an example of using a dynamic T-SQL query and then extracting the results should you have more than one column of returned values (notice the dynamic table name):
DECLARE
#strSQLMain nvarchar(1000),
#recAPD_number_key char(10),
#Census_sub_code varchar(1),
#recAPD_field_name char(100),
#recAPD_table_name char(100),
#NUMBER_KEY varchar(10),
if object_id('[Permits].[dbo].[myTempAPD_Txt]') is not null
DROP TABLE [Permits].[dbo].[myTempAPD_Txt]
CREATE TABLE [Permits].[dbo].[myTempAPD_Txt]
(
[MyCol1] char(10) NULL,
[MyCol2] char(1) NULL,
)
-- an example of what #strSQLMain is : #strSQLMain = SELECT #recAPD_number_key = [NUMBER_KEY], #Census_sub_code=TEXT_029 FROM APD_TXT0 WHERE Number_Key = '01-7212'
SET #strSQLMain = ('INSERT INTO myTempAPD_Txt SELECT [NUMBER_KEY], '+ rtrim(#recAPD_field_name) +' FROM '+ rtrim(#recAPD_table_name) + ' WHERE Number_Key = '''+ rtrim(#Number_Key) +'''')
EXEC (#strSQLMain)
SELECT #recAPD_number_key = MyCol1, #Census_sub_code = MyCol2 from [Permits].[dbo].[myTempAPD_Txt]
DROP TABLE [Permits].[dbo].[myTempAPD_Txt]
Using Temp table solves the problem but I ran into issues using Exec so I went with the following solution of using sp_executesql:
Create TABLE #tempJoin ( Old_ID int, New_ID int);
declare #table_name varchar(128);
declare #strSQL nvarchar(3072);
set #table_name = 'Object';
--build sql sting to execute
set #strSQL='INSERT INTO '+#table_name+' SELECT '+#columns+' FROM #tempJoin CJ
Inner Join '+#table_name+' sourceTbl On CJ.Old_ID = sourceTbl.Object_ID'
**exec sp_executesql #strSQL;**