sql select's using mysql query browser

Question

I am wondering why when I use MySQL Query Browser and double click table names the sql statements look like this:

SELECT * FROM database.table t;

where t = the first letter of the table... What is the purpose of this letter? I am just curious

Answer 1

The t is an alias for the table. It helps when writing queries with :

• many columns in the select list

• (many) joins where writing the full table name would be unreadable

  Foo f INNER JOIN Customers c on c.ID = f.CustomerID LEFT JOIN BAR b on b.ID=f.ID

• if you wanted 2+ copies of the same table, you could alias them with different names:

  Invoices i LEFT JOIN Invoices i2 on i.ID = i2.MasterInvoiceID

• long table/view names that would be cumbersome to keep writing/reading. Naming conventions sometimes are the culprit. Imagine a data warehouse table like:

  InvoicesThatAreOverdue_Temp_Holding_20101128

It's not required, but the MySQL Query Browser is helping promote the use of aliases. Here's hoping it helps developers write readable code!

Answer 2

It is an alias that will allow you to shorten your references

For example

Select * from table1 t1
Inner Join table2 t2 on t1.PK = t2.FK

Instead of this

Select * from table1 
Inner Join table2 on table1.PK = table2.FK

Answer 3

It is known as alias :)

In SQL, an alias name can be given to a table or to a column. You can give a table or a column another name by using an alias. This can be a good thing to do if you have very long or complex table names or column names.

Answer 4

It's a table alias. Here is a short tutorial on using aliases.

Answer 5

You're actually using a shortcut (alias) to give a new name to the table.

// this is the full command but you can leave out AS if you want
SELECT * FROM database.table AS t;

Table aliasing is pretty useful for larger queries when you're joining multiple tables.