Coding In SQL

Structure Query Language Common query language used in database management systems Common query language used in database management systems In Access In Access –can view SQL code by going into SQL view –can build queries in SQL View mode

Common SQL Keywords Select Select From From Where Where Group By Group By Having Having Order By Order By

Select Lists the fields that you want to display in the query Lists the fields that you want to display in the query Fields must contain the table name and the field name (Employee.EmpLast) Fields must contain the table name and the field name (Employee.EmpLast)

From Lists the table or tables involved in the query Lists the table or tables involved in the query Separate table names with commas Separate table names with commas

Where Lists the criteria that apply Lists the criteria that apply Where Employee.EmpLast=“Jones” Where Employee.EmpLast=“Jones”

Group By Groups records with identical values in the specified fields (usually to calculate a summary statistic) Groups records with identical values in the specified fields (usually to calculate a summary statistic) Group by Employee.JobID Group by Employee.JobID

Having List the conditions for selecting grouped records, connected by AND, OR, or NOT List the conditions for selecting grouped records, connected by AND, OR, or NOT Having (Employee.JobID) = 3 OR (Employee.JobID) = 4 Having (Employee.JobID) = 3 OR (Employee.JobID) = 4

Order By Specify sorting specifications Specify sorting specifications Order By Employee.JobID DESC Order By Employee.JobID DESC

Sample SQL Query Give list of employees with a JobID of 3 Give list of employees with a JobID of 3 Select Employee.EmpFirst, Employee.EmpLast From Employee Where Employee.JobID = 3 Order By Employee.EmpLast;

Results

SQL Queries with Several Tables Use the words INNER JOIN, RIGHT JOIN, or LEFT JOIN Use the words INNER JOIN, RIGHT JOIN, or LEFT JOIN To show the link (inner join) between two tables, use this code: To show the link (inner join) between two tables, use this code: FROM Employee INNER JOIN EmployeeTraining ON Employee.EmpID = EmployeeTraining.EmpID

Sample Query Give a list of employee training classes taken, the date, and the employee who took the class (sort in alphabetic order by last name) Give a list of employee training classes taken, the date, and the employee who took the class (sort in alphabetic order by last name) –SELECT Employee.EmpFirst, Employee.EmpLast, EmployeeTraining.ClassID, EmployeeTraining.Date –FROM Employee INNER JOIN EmployeeTraining ON Employee.EmpID = EmployeeTraining.EmpID –ORDER BY Employee.EmpLast;

Results