SQL Server transaction count after EXECUTE indicates a mismatching number of BEGIN and COMMIT statements

There are situations where you might receive this error message “Transaction count after EXECUTE indicates a mismatching number of BEGIN and COMMIT statements. Previous count = 0, current count = 1.”. Even when using a TRY CATCH block in the stored procedure and a ROLLBACK in the catch block, this error still occurs. One reason this is not captured is because fatal errors are not caught and the transaction remains open. In this tip we will look at how you can handle this issue.

Refer to this article for solution;

Find all columns with a specific column name in database

Recently i had to search for a specific column in database. My assumption was that the column name would be same as the column name in parent table. For example Person table PersonID column would be name same in all reference tables.

USE MyDatabase
--find all columns with a specific name in database
SELECT  OBJECT_SCHEMA_NAME(ac.object_id) SchemaName, 
        OBJECT_NAME(ac.object_id) TableName, 
        ac.name as ColumnName, tp.name DataType
FROM sys.all_columns ac
INNER JOIN sys.types tp ON tp.user_type_id = ac.user_type_id
WHERE ac.name = 'YourColumnName'
GO

Resources

Read more here…

SQL Server basic command

This is a handy list of basic commands;

Append a new column to table

ALTER TABLE table_name
ADD column_name data_type column_constraint;

Append multiple columns to a table

ALTER TABLE table_name
ADD 
    column_name_1 data_type_1 column_constraint_1,
    column_name_2 data_type_2 column_constraint_2,
    ...,
    column_name_n data_type_n column_constraint_n;

Create a new table

CREATE TABLE table_name (
    colulmn_name data_type_1 IDENTITY PRIMARY KEY,
    colulmn_name data_type_2 NOT NULL,
    column_name data_type_3  NULL
);

Insert results of SPROC into temp table

I would like to do something like this;

SELECT * INTO #tmpADD EXEC mySPROC 'Params'

SQL Server doesn’t support this and I don’t want to use OPENQUERY like this.

Select @@ServerName
EXEC sp_serveroption @@ServerName, 'DATA ACCESS', TRUE

SELECT  *
INTO    #tmpADD
FROM    OPENQUERY(YOURSERVERNAME, 'EXEC db.schema.mySPROC 1')

Using OPENROWSET will get the job done, but it will incur some additional overhead for opening up local connections and marshalling data. It also may not be an option in all cases since it requires an ad hoc query permission which poses a security risk and therefore may not be desired. Also, the OPENROWSET approach will preclude the use of stored procedures returning more than one result set. Wrapping multiple inline table-value user-defined functions in a single stored procedure can achieve this.

The first work around is to define structure of return values of stored procedure and create temp table.

CREATE TABLE #tmpADD
(
   COL1 INT,
   COL2 INT
)

INSERT INTO #tmpADD
Exec mySPROC 'Params'

This will work but if we ever add additional columns to the mySPROC stored procedure, this will blow up.

The second work around is to use an inline table-valued user-defined function. This is essentially a stored procedure (will take parameters) that returns a table as a result set; and therefore will place nicely with an INTO statement.

If we still have a driving need for a stored procedure, we can wrap the inline table-valued user-defined function with a stored procedure. The stored procedure just passes parameters when it calls select * from the inline table-valued user-defined function.

So for instance, Here is an inline table-valued user-defined function to get a list of customers for a particular region:

CREATE FUNCTION CustomersByRegion 
(  
    @RegionID int  
)
RETURNS TABLE 
AS
RETURN 
  SELECT *
  FROM customers
  WHERE RegionID = @RegionID
GO

We can then call this function to get the results as such:

SELECT * FROM CustomersbyRegion(1)

Or to do a SELECT INTO:

SELECT * INTO CustList FROM CustomersbyRegion(1)

If we still need a stored procedure, then wrap the function as such:

CREATE PROCEDURE mySPROC
(  
    @regionID int  
)
AS
BEGIN
     SELECT * FROM CustomersbyRegion(@regionID);
END
GO

I think this is the most ‘hack-less’ method to obtain the desired results. It uses the existing features as they were intended to be used without additional complications. By nesting the inline table-valued user-defined function in the stored procedure, we have access to the functionality in two ways. Plus! We have only one point of maintenance for the actual SQL code.

If inline table value functions returns more than one schema then its is not possible to use IF statement in it. In this case we have to use table value function not inline table value function;

-- =============================================
-- Author:		Shahzad Khan
-- Create date: 2/1/2022
-- Description:	returns zoo data
-- SELECT * FROM  [dbo].[fn_getZooAnimal](2)
-- =============================================
CREATE FUNCTION fn_getZooAnimal 
(
	-- Add the parameters for the function here
	@Id int
)
RETURNS 
@Table_Var TABLE 
(
	-- Add the column definitions for the TABLE variable here
	Id int, 
	AnimalName NVARCHAR(50)
)
AS
BEGIN
	-- Fill the table variable with the rows for your result set
	IF (@Id = 1)
	BEGIN
		INSERT @Table_Var
		SELECT @Id, 'Monkey'
	END
	ELSE
	BEGIN
		INSERT @Table_Var
		SELECT @Id, 'Deer'
	END
	RETURN 
END
GO

Resources

https://stackoverflow.com/questions/653714/insert-results-of-a-stored-procedure-into-a-temporary-table?page=1&tab=votes#tab-top

SQL Server Merge Statement

I have 2 tables one containing historical data using type 2 SCD (Slowly changing dimensions) called DimBrand and another containing just the latest dimension data called LatestDimBrand. Using the merge function I will insert new records from LatestDimBrand into DimBrand, I will archive (apply an end date) to any DimBrand records which do not appear in the latest data, and finally enter a new record and archive the old record for any Brands which may have changed.

DimBrand (the target of our Inserts, Updates, Deletes) and DimLatestBrand (the source for Inserts,Updates,Deletes):

DimBrand table
DimLatestBrand table

Here is complete merge statement;

INSERT #DimBrand    ([BrandCode],[BrandName],[StartDate])
SELECT                 [BrandCode],[BrandName],getdate()                                    
FROM                (
                    MERGE #DimBrand AS Target
                    USING    (
                            SELECT    [BrandCode],[BrandName],[StartDate],[EndDate]                       
                            FROM    #LatestDimBrand
                            ) AS Source
                    ON     (Target.[BrandCode] = Source.[BrandCode])    
                    -------------------------------                       
                    WHEN MATCHED AND Target.[BrandName] <> Source.[BrandName]
                        THEN
                        UPDATE SET Target.[EndDate] = getdate()
                    -------------------------------
                    WHEN NOT MATCHED BY TARGET 
                        THEN
                        INSERT ( 
                                [BrandCode]                        
                                ,[BrandName]                    
                                ,[StartDate]              
                                ,[EndDate]                                            
                        )
                        VALUES (      
                                Source.[BrandCode], 
                                Source.[BrandName], 
                                Source.[StartDate],
                                Source.[EndDate]   
                        )
                    -------------------------------
                    WHEN NOT MATCHED BY SOURCE 
                        THEN 
                        UPDATE SET Target.[EndDate] = getdate()
                    -------------------------------
                    OUTPUT $Action, Source.*
                    ) As i([Action],[BrandCode],[BrandName],[StartDate],[EndDate])
                    -------------------------------
WHERE                [Action] = 'UPDATE'
AND                    BrandCode IS NOT NULL

Resources

https://docs.microsoft.com/en-us/sql/t-sql/statements/merge-transact-sql?view=sql-server-ver15

https://www.mssqltips.com/sqlservertip/2883/using-the-sql-server-merge-statement-to-process-type-2-slowly-changing-dimensions/