String that contains a SELECT with several pairs of variables and values. Using EXEC gives me an undeclared variable error - sql

Question

The process is more complex than the previous one.
I have a stored procedure that retrieves the variable #parameters_list NVARCHAR(2000).
This #parameters_list variable contains a series of parameters that I retrieve from a transactional website. Usually, it contains a series of parameters with their respective values. The parameters vary depending on the type of transaction being executed.
Here is a more complete description of the process:
Suppose, that #parameters_list comes with the following data from the website
#parameters_list = 'id_client=1;id_dealer=1;id_country=1;id_region=5;id_city=2;sede=2;id_tower=8;main_code=CHI-01-01;id_location=2;city=Main City;data_name=Box 01;title=Major KPI;tittle2=Detecting relevant Data;detail=none'
Inside the stored procedure, I have in part the following declarations and creation of a temporary table:
DECLARE #id_client INT,
#id_dealer INT,
#id_country INT,
#id_region INT,
#id_city INT,
#id_tower INT,
#main_code VARCHAR(120),
#id_location INT,
#city VARCHAR(50),
#data_name VARCHAR(100),
#detail VARCHAR(100),
#title VARCHAR(200),
#title2 VARCHAR(300)
DECLARE #stringData NVARCHAR(2000),
#data_key VARCHAR(30)
DECLARE #ident INT
CREATE TABLE [dbo].[#TEMP_DATA](
[ident] [int] IDENTITY(1,1) NOT NULL,
[data_key] [varchar](100) NULL,
[data_value] [varchar](100) NULL
) ON [PRIMARY]
Later, I execute another stored procedure (PANKI_UTILS..SP_KEY_VALUE_PARAMETER) whose main task is to separate the variables with their respective values. Then, the result is stored in the temporary table #TEMP_DATA.
EXEC PANKI_UTILS..SP_KEY_VALUE_PARAMETER
#parameters_list,
';',
'=',
#ident output
INSERT INTO
#TEMP_DATA
SELECT
[key],
value
FROM PANKI_UTILS..KEY_VALUE
WHERE ind = #ident
ORDER BY [key]
The content of the #TEMP_DATA table is as follows:
What the image shows is a table where the column data_key is the name of the variable and "data value" the value of that variable.
Finally, I store all the content of the table in a #stringData variable
SET #stringData = (SELECT string_agg('#'+CAST(data_key AS VARCHAR(30)) +'='+ CAST(data_value AS VARCHAR(500)), ',') FROM #TEMP_DATA)
SELECT #stringData
#city=Main City,#data_name=Box 01,#detail=none,#id_city=2,#id_client=1,#id_country=1,#id_dealer=1,#id_location=2,#id_region=5,#id_sede=2,#id_tower=8,#main_code=CHI-01-01,#title=Major KPI,#tittle2=Detecting relevant Data
That's why I'm looking for a way to retrieve the variables in the form of; #city, #data_name and etc.
An alternative was to use the sp_executesql command, but I don't really know how to use it to retrieve those variables.
If you can help me, I would appreciate it. Thanks.

Answer 1

The TSQL you provide as a parameter to execute is run in a different scope than your parent script. It doesn't have access to local variables declared outside of it.
If you need to use execute, try something like this:
declare #string_data varchar(max);
SET #string_data = '
declare #City varchar(255), #Product varchar(255) , #Zip varchar(255);
SELECT #city=''Baltimore'', #product= ''car'', #zip=''630930'';
SELECT #city AS city, #product AS product, #zip AS zip;
';
EXEC(#string_data);
But you might be able to get away without using it:
declare #City varchar(255), #Product varchar(255) , #Zip varchar(255);
SELECT #city='Baltimore', #product= 'car', #zip='630930';
SELECT #city AS city, #product AS product, #zip AS zip;

Answer 2

When you use EXEC(#String), you're opening a new session and starting a new transaction. That new session that is opened is not aware of any variable from the calling session that executed the EXEC command.
Further, it doesn't really look like you need to use dynamic SQL and execute right here.
Without know what the rest of your query looks like, try this.
SELECT #city=Baltimore, #product= car, #zip=630930
SELECT #city AS city, #product AS product, #zip AS zip