SQL 带字母和数字的Where子句等查询

Question

I have a table with project numbers. The project numbers have different formats. I want to filter just the project numbers starting with C and 4 numbers (ie C1234 ) and with underscore 3 numbers (ie C1234_123 ). Other formats that i don´t want have a lot more numbers, points in between etc.

Can you help me with the WHERE clause?

WHERE
    Projectnumber LIKE 'C____%'  

Here I also get the project numbers that have more than 4 numbers after the C . How to define a filter for this format C1234_123 ?

KR Julia

Answer 1

Here is the answer with a working example ,

SELECT
            [ProjectNumber]
    FROM
            [Stuff]
    WHERE
            [ProjectNumber] LIKE 'C[0-9][0-9][0-9][0-9]\_[0-9][0-9][0-9]' ESCAPE '\';

Note the use of the ESCAPE clause to prevent the _ being treated like a wildcard.