Dynamic SQL Server query

问题

I am writing a dynamic insert query in a stored procedure. I am receiving the column names as parameter to my stored procedure.

For example, I have an Employee table with EmployeeId and EmployeeName columns. I need to append EMP_ before each employee name while inserting the data into Department table from Employee table.

Non-dynamic query looks like this.

 INSERT INTO Department(EmployeeId, EmployeeName)
     SELECT 
         EmployeeId, 'EMP_' + EmployeeName
     FROM 
         Employee

If I write a dynamic insert

 SET @SqlCommand =
          'INSERT INTO ' + @DepartmentTable + '(' + @EmployeeIdColumn + ',' + @EmployeeNameColumn + ')' +
          'SELECT ' + @EmployeeIdColumn + ',''EMP_''' + @EmployeeNameColumn + '''' +     
          'FROM ' +
              @EmployeeTable + ' WTB '  

        EXEC sp_executesql
        @stmt        = @SqlCommand

The issue is, for the EmployeeName column, it is inserting "EMP_EmployeeName" instead of actual employee name. I tried putting quotes before and after EmployeeNameColumn, but it didn't work. How can I fix it?

回答1:

You need just one + after EMP_'', and remove it after ' WTB '. Also i fixed some spaces:

SET @SqlCommand =
'INSERT INTO ' + @DepartmentTable + ' (' + @EmployeeIdColumn + ',' + @EmployeeNameColumn + ')' +
' SELECT ' + @EmployeeIdColumn + ',''EMP_''+' + @EmployeeNameColumn +      
' FROM ' + @EmployeeTable + ' WTB '

If you PRINT @SqlCommand you will get something like this:

INSERT INTO Department (EmpId,EmpName) SELECT EmpId,'EMP_'+EmpName FROM Employee WTB

And one note: better use QUOTENAME with table/column names. It will help to avoid situations where column has spaces in the name like 'Employee Name':

SET @SqlCommand =
'INSERT INTO ' + QUOTENAME(@DepartmentTable) + '(' + QUOTENAME(@EmployeeIdColumn) + ',' + QUOTENAME(@EmployeeNameColumn) + ')'+
' SELECT ' + QUOTENAME(@EmployeeIdColumn) + ',''EMP_''+' + QUOTENAME(@EmployeeNameColumn) + 
' FROM ' + QUOTENAME(@EmployeeTable) + ' WTB '

To get:

INSERT INTO [Department]([EmpId],[EmpName]) SELECT [EmpId],'EMP_'+[EmpName] FROM [Employee] WTB

回答2:

Try using the CONCAT function.

-- Syntax for SQL Server, Azure SQL Database, Azure SQL Data Warehouse, Parallel Data Warehouse  

CONCAT ( string_value1, string_value2 [, string_valueN ] )

Your query would then look like this :

INSERT INTO deptTable(empId,empName) 
SELECT empId,concat('EMP_', empName) as empName FROM empTable

PS: Looks like I misunderstood your question.

INSERT INTO deptTable(empId,empName) 
SELECT empId,'SUFFIX'+empName as empName FROM empTable

will also work. I guess you wanted it for the stored proc.

In any case the concat should still do it.

来源：https://stackoverflow.com/questions/39313748/dynamic-sql-server-query

标签

sql

sql-server

tsql

dynamic-sql