SQL（MS SQL 服务器）返回列值作为乘法的结果

Question

I have a table in SQL that looks like the below:

table is like the below:

Partno   b5      b6      b7
A        3*38    4*38    5*38 
B        4*1100  8*1100  15*1100

Column b5,b6,b7 is currently nvarchar. Can I check how to convert this column to int with the value of the multiplication? Eg if column b5=3*38 I would like to return as 114 etc.

Thank you very much.

Answer 1

With the following assumption, you can use split the query and do multiplication.

• You are using sql server
• There is only multiplication in the columns
• There is only two values in multiplication
• So ultimately, you have just a*b in the columns

You can use following query:

Select partno, 
       PARSENAME(REPLACE(b5,'*','.'),2) * PARSENAME(REPLACE(b5,'*','.'),1) as b5_res,
       PARSENAME(REPLACE(b6,'*','.'),2) * PARSENAME(REPLACE(b6,'*','.'),1) as b6_res,
       PARSENAME(REPLACE(b7,'*','.'),2) * PARSENAME(REPLACE(b7,'*','.'),1) as b7_res
From your_table t

Answer 2

Given the structure of the data, you could use simple string operations:

select t.*,
       multiple * try_convert(int, left(b4, charindex('*', b4) - 1)),
       multiple * try_convert(int, left(b5, charindex('*', b5) - 1)),
       multiple * try_convert(int, left(b6, charindex('*', b6) - 1))
from t;

Here is a db<>fiddle.