T-SQL: joining tables when the referencing key in one of the tables is in three columns instead of one.
Posted on 2013-06-07
Table2 has three columns with the values that reference the same parent column1 in table1 . Either one of the columns has the value, or two, or all three, otherwise the value is empty string. That's how we can join those two tables using the value that exists in one of three columns and the value in the table2 column1.
I have to create additional column in the table2 and populate it with the matching value from the column2 of the parent table1.
Any ideas about the best way to accomplish the task?