SQL SELECT Statement

Source: Internet
Author: User
This chapter explains the SELECT and select * Statements.

SQL SELECT Statement

Select statements are used to select data from a table.

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

SQL SELECT Syntax

SELECT column name from table name

And:

SELECT * FROM table name

Note: The SQL statement is not case sensitive. Select is equivalent to select.

SQL SELECT Instance

To get the contents of a column named "LastName" and "FirstName" (from a database table named "Persons"), use a SELECT statement like this:

SELECT Lastname,firstname from Persons

"Persons" table:

Id LastName FirstName Address City

1 Adams John Oxford Street London

2 Bush George Fifth Avenue New York

3 Carter Thomas Changan Street Beijing

Results:

LastName FirstName

Adams John

Bush George

Carter Thomas

SQL SELECT * Instance

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

Use the symbol * instead of the name of the column, just like this:

SELECT * from Persons

Tip: An asterisk (*) is a shortcut to select all columns.

Results:

Id LastName FirstName Address City

1 Adams John Oxford Street London

2 Bush George Fifth Avenue New York

3 Carter Thomas Changan Street Beijing

Navigating in the result set (Result-set)

The results obtained by the SQL query program are stored in a result set. Most database software systems allow the use of programming functions to navigate the result set, such as: Move-to-first-record, Get-record-content, Move-to-next-record, and so on.

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