SQL exercises on employee Database: List the no. of employees in each department where the no. is less than 4
SQL employee Database: Exercise-101 with Solution
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101. From the following tables, write a SQL query to find those departments where less than four employees work. Return department ID, number of employees.
Sample table: employees
Sample Solution:
SELECT dep_id,
count(*)
FROM employees
GROUP BY dep_id
HAVING count(*)<4;
Sample Output:
dep_id | count --------+------- 1001 | 3 (1 row)
Relational Algebra Expression:
Relational Algebra Tree:
Practice Online
Sample Database: employee
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Previous: From the following table, write a SQL query to find those departments where at least two employees work as a SALESMAN in each grade. Return department name, grade and number of employees.
Next: From the following tables, write a SQL query to find those departments where at least two employees work. Return department name, number of employees.
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SQL: Tips of the Day
SQL Server SELECT into existing table.
INSERT INTO dbo.TABLETWO SELECT col1, col2 FROM dbo.TABLEONE WHERE col3 LIKE @search_key
This assumes there's only two columns in dbo.TABLETWO - you need to specify the columns otherwise:
INSERT INTO dbo.TABLETWO (col1, col2) SELECT col1, col2 FROM dbo.TABLEONE WHERE col3 LIKE @search_key
Database: SQL Server
Ref: https://bit.ly/3y6tpA3
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