SQL SELECT Statement

This chapter will explain the SELECT and the SELECT * statements.

The SQL SELECT Statement

The SELECT statement is used to select data from a database.

The result is stored in a result table, called the result-set.

SQL SELECT Syntax

SELECT column_name(s)
FROM table_name
and

SELECT * FROM table_name
 Note: SQL is not case sensitive. SELECT is the same as select.



An SQL SELECT Example

The "Persons" table:

P_Id    LastName     FirstName    Address            City
1            Hansen           Ola             Timoteivn 10    Sandnes
2           Svendson       Tove             Borgvn 23        Sandnes
3            Pettersen       Kari             Storgt 20         Stavanger
Now we want to select the content of the columns named "LastName" and "FirstName" from the table above.

We use the following SELECT statement:

SELECT LastName,FirstName FROM Persons
The result-set will look like this:

LastName    FirstName
Hansen           Ola
Svendson       Tove
Pettersen        Kari

SELECT * Example

Now we want to select all the columns from the "Persons" table.

We use the following SELECT statement:

SELECT * FROM Persons

Tip: The asterisk (*) is a quick way of selecting all columns!

The result-set will look like this:

P_Id      LastName     FirstName        Address             City
1             Hansen            Ola                 Timoteivn 10       Sandnes
2            Svendson         Tove                Borgvn 23           Sandnes
3             Pettersen        Kari                 Storgt 20             Stavanger

Navigation in a Result-set

Most database software systems allow navigation in the result-set with programming functions, like: Move-To-First-Record, Get-Record-Content, Move-To-Next-Record, etc