Mapping dynamic column names in sql server

问题

DECLARE @step VARCHAR(25) = '15';
DECLARE @COL VARCHAR(50) = step_col_@step;
UPDATE table_tblName SET @COL=<some value> WHERE <condition>

I have the above query where @COL is supposed to be dynamic i.e. step_col_1,step_col_2,step_col_3......step_col_18. How can I achieve this without If-else condition in sql server?

回答1:

Try the below query,

DECLARE @COL VARCHAR(50) = 'step_col_'+@step

回答2:

Pass the variables like this to form a dynamic sql query

DECLARE @step VARCHAR(25) = '15';
DECLARE @COL VARCHAR(50) = 'step_col_'+@step
exec ('UPDATE table_tblName SET '+@COL+'=<some value> WHERE <condition>')

回答3:

 DECLARE @step VARCHAR(25) = '15';
 DECLARE @COL VARCHAR(50) = 'step_col_'+@step;
 DECLARE @String VARCHAR(500) = ''
 SET @String = 'UPDATE table_tblName SET '''+@COL+''' = <some value> WHERE  
 <condition>' 
 EXEC (@String)

回答4:

DECLARE @step VARCHAR(25) = '15';
DECLARE @COL VARCHAR(50) 
SET @COL = 'step_col'+@step;

UPDATE table_tblName SET @COL=<some value> WHERE <condition>

来源：https://stackoverflow.com/questions/42624480/mapping-dynamic-column-names-in-sql-server