MySQL Aliases
• COLUMN ALIASES are used to give column headings in your result set , so that it is easier to read.
• TABLE ALIASES is used for giving alternative name to table .so that it is easier to read in SQL statement.In Mysql statement tables can be given an alias alternative name for local use in the statement
• When you write SQL query using TABLE ALIASES a column of an aliased table, the alias must be used as qualifier – not the table name.
• Always alias follows after the table name
SYNTAX
SELECT column as COLUMN ALIASES
FROM table as TABLE ALIASES
Table structure Used for Example explanation
country
+—————-+————+
| Field | Type |
+—————-+————+
| Code | char(3) |
| Name | char(52) |
| Continent | char(40) |
| Region | char(26) |
| SurfaceArea | float(10,2)|
| IndepYear | smallint(6)|
| Population | int(11) |
| LifeExpectancy | float(3,1) |
| GNP | float(10,2)|
| GNPOld | float(10,2)|
| LocalName | char(45) |
| GovernmentForm | char(45) |
| HeadOfState | char(60) |
| Capital | int(11) |
| Code2 | char(2) |
+—————-+————+
City
+————-+———-+
| Field | Type |
+————-+———-+
| ID | int(11) |
| Name | char(35) |
| CountryCode | char(3) |
| District | char(20) |
| Population | int(11) |
+————-+———-+
Example for MySQL Aliases
SELECT C.Name, Country.Name
FROM Country, City AS C
WHERE Capital = C.ID;
Output of Above Example
+————+———————-+
| Name | Name |
+————+———————-+
| Kabul | Afghanistan |
| Amsterdam | Netherlands |
| Willemstad | Netherlands Antilles |
| Tirana | Albania |
| Alger | Algeria |
+————+———————-+
5 rows in set (0.41 sec)