SQL ERROR LINE is one of the SQL System Functions that will return the line number at which the error has occurred. This ERROR_LINE function works within the scope of a SQL TRY CATCH block.
For example, we write a series of statements inside the TRY block. If the server finds an error, then SQL ERROR_LINE() inside the CATCH block will execute and returns the corresponding line number at which error occurred. ERROR LINE is handy to debug the issue. The basic syntax of the Error_Line in SQL Server is
ERROR_LINE()
SQL ERROR LINE example
In this example, we are going to show you how to use the Error_Line function to return the line number at which the error has occurred.
BEGIN TRY
DECLARE @Number tinyint,
@Result tinyint;
SET @Number = 252;
SET @Result = @Number + 10;
SELECT @Number AS Number,
@Result AS Result;
END TRY
BEGIN CATCH
PRINT N'Error Line = ' + CAST(ERROR_LINE() AS nvarchar(100));
PRINT N'Error Message = ' + CAST(ERROR_MESSAGE() AS nvarchar(100));
END CATCH

First, we declared two SQL Server tinyint variables. Refer to the SQL tutorial page.
DECLARE @Number tinyint,
@Result tinyint;
Next we assigned 252 to @Number variable, and then we added 10 to that variable which will become 262 (Result).
SET @Number = 252; SET @Result = @Number + 10;
As we all know, tinyint holds numbers from 0 to 255, which means Overflow. So, it will exit from the TRY block and execute the statements inside our CATCH block. We used the SQL ERROR_MESSAGE function to display the error description
PRINT N'Error Line = ' + CAST(ERROR_LINE() AS nvarchar(100)); PRINT N'Error Message = ' + CAST(ERROR_MESSAGE() AS nvarchar(100));
ERROR LINE example 2
In this SQL error line example, we are going to find the result of integer /0.
BEGIN TRY
DECLARE @Number int,
@Result int;
SET @Number = 252;
SET @Result = @Number / 0;
SELECT @Number AS Number,
@Result AS Result;
END TRY
BEGIN CATCH
PRINT N'Error Line = ' + CAST(ERROR_LINE() AS nvarchar(100));
PRINT N'Error Message = ' + CAST(ERROR_MESSAGE() AS nvarchar(100));
END CATCH

Within the TRY block we are finding the result of 252/0
SET @Result = @Number / 10;
As we all know that the above statement will throw an error so, statement inside the CATCH block will be executed.