FROM bang
[WHERE dieukien];
Parameters :
Note :
Take a look and explore some examples of COUNT functions in SQL Server.
Suppose, we have the following data table:
Example 1: Count the number of categories in the table
SELECT COUNT(*)
FROM Quantrimang
WHERE Sobai > 100;
Result: 5
In this example we count the number of categories in the Quantrimang table that are larger than 100.
Example 2: Use DISTINCT
The DISTINCT and COUNT commands can be used together to count the number of duplicate results.
SELECT COUNT(DISTINCT Sobai)
FROM Quantrimang
WHERE Sobai > 100;
Result: 4
This example uses the keyword DISTINCT, so the repeated values are counted only once. In the given data table, the value '101' appears twice, but only once, so the total number of calculated lines will be 4.
Example 3: Using GROUP BY
The following example counts all records related to a large section and you will do the following:
SELECT Chuyenmuclon, COUNT(Chuyenmuccon) AS "So luong"
FROM Quantrimang
GROUP BY Chuyenmuclon;
Result:
Chuyenmuclon So luong
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