Check Excel file destination temp table in SSIS? - sql

Question

I have created ssis package to generate excel file dynamically from sql table.
But when I try to check whether that excel connection temp table if present or not using below query in sql task it gets failed syntax error
IF object_id(MyExcel) is not null
CREATE TABLE `MyExcel` (
`CUSIP` varchar(50),
`FaceAmount` decimal(18,4),
`Portfolio` varchar(50),
`PositionDate` DateTime,
`PositionCost` decimal(18,6),
`CurrentPrice` decimal(18,6)
)
else drop table MyExcel
ERROR :
[Execute SQL Task] Error: Executing the query "IF object_id(MyExcel) is not null
CREATE TABLE `..." failed with the following error: "Invalid SQL statement; expected 'DELETE', 'INSERT', 'PROCEDURE', 'SELECT', or 'UPDATE'.". Possible failure reasons: Problems with the query, "ResultSet" property not set correctly, parameters not set correctly, or connection not established correctly.
Please advise?
I have tried with answer
IF OBJECT_ID(N'MyExcel') IS NOT NULL
BEGIN
DROP TABLE MyExcel;
END;
CREATE TABLE [MyExcel]
(
[CUSIP] VARCHAR(50),
[FaceAmount] DECIMAL(18,4),
[Portfolio] VARCHAR(50),
[PositionDate] DATETIME,
[PositionCost] DECIMAL(18,6),
[CurrentPrice] DECIMAL(18,6)
);
But still getting same error for statements
IF OBJECT_ID(N'MyExcel') IS NOT NULL
BEGIN
DROP TABLE MyExcel;
END;
I'm using this query inside SQL TASK
Connection type is EXCEL

Answer 1

This appears to be a combination of SQL-Server syntax (OBJECT_ID('ObjectName')) and MySQL syntax (back ticks for object names). I am assuming you are connecting to a SQL-Server database so you should qualify your object names with []. e.g.
IF OBJECT_ID(N'MyExcel') IS NOT NULL
BEGIN
CREATE TABLE [MyExcel]
(
[CUSIP] VARCHAR(50),
[FaceAmount] DECIMAL(18,4),
[Portfolio] VARCHAR(50),
[PositionDate] DATETIME,
[PositionCost] DECIMAL(18,6),
[CurrentPrice] DECIMAL(18,6)
);
END;
ELSE
BEGIN
DROP TABLE MyExcel;
END;
However, I believe your logic is flawed, your statement is saying "If the table exists, create it, if not drop it", so if it does already exist you will get an error saying the table already exists, if it doesn't then you will get an error saying you can't drop it because it doesn't exist. What you would really want is:
IF OBJECT_ID(N'MyExcel') IS NULL
BEGIN
CREATE TABLE [MyExcel]
....
However, this still presents you with a problem, since if the table exists before the task is run, it won't after, if it doesn't exist before then it will be created, which means whether or not the table exists after the task completes is dependent on whether or not the table exists before. I would imagine you want to do something like:
IF OBJECT_ID(N'MyExcel') IS NULL
BEGIN
CREATE TABLE [MyExcel]
(
[CUSIP] VARCHAR(50),
[FaceAmount] DECIMAL(18,4),
[Portfolio] VARCHAR(50),
[PositionDate] DATETIME,
[PositionCost] DECIMAL(18,6),
[CurrentPrice] DECIMAL(18,6)
);
END;
ELSE
BEGIN
TRUNCATE TABLE [MyExcel];
-- If you don't want to truncate the table and want it with
-- it's previous data in just remove the entire `else` clause
END;
Or
IF OBJECT_ID(N'MyExcel') IS NOT NULL
BEGIN
DROP TABLE MyExcel;
END;
CREATE TABLE [MyExcel]
(
[CUSIP] VARCHAR(50),
[FaceAmount] DECIMAL(18,4),
[Portfolio] VARCHAR(50),
[PositionDate] DATETIME,
[PositionCost] DECIMAL(18,6),
[CurrentPrice] DECIMAL(18,6)
);
i.e. after the task is run you will always have an table called MyExcel in the database, so you know it will be there when you get to the next step in your SSIS package.
ADDENDUM
As far as I know, you cannot use IF with an excel connection. There is an article here on querying the meta data from an excel workbook so you can check if a table exists. This is probably the technically correct way of doing it.
I was able to create a work around though, by having an Execute SQL Task with the following SQL:
DELETE
FROM MyExcel;
Then adding another Execute SQL Task to the On Error event handler to run:
CREATE TABLE MyExcel
(
CUSIP VARCHAR(50),
FaceAmount DECIMAL(18,4),
Portfolio VARCHAR(50),
PositionDate DATETIME,
PositionCost DECIMAL(18,6),
CurrentPrice DECIMAL(18,6)
);
So if the table does not exists, the delete statement will throw an error, which will trigger the create table statement. Thus ensuring after the task has run the table MyExcel definitely exists.
These tasks could be reversed, the result would be the same

Answer 2

You don't create an excel file with CREATE TABLE. If you come to think of excel file as database, the tables would be.. worksheets :).
To create an excel file, you'd Excel Connection Manager. You need to point it once to a template file, and after you set up excel destination with correct expressions, the file will be created. If it already exists, you just need to redirect the error.
And then you use Execute Sql to create the table (i.e. worksheet), of your desired structure.

Answer 3

You can add a Execute SQL Task to the end of the control flow to Drop the Excel table(s) in the package. This will leave the environment ready for the package to be processed again.