I have two tables, both with a column called TestID.

Table 1 has 4000 rows Table 2 has 1000 rows.

I would like to see how many rows in table 2 have the same value in the TestID column compared to table 1.

CodePudding user response：

A guess at what you're expecting:

select count(t2.testId) T2Matches
from t1 join t2 on t1.TestId = t2.TestId;