How To Define and Use Table Alias Names

Q

How To Define and Use Table Alias Names? - MySQL FAQs - SQL SELECT Statements with JOIN and Subqueries

✍: FYIcenter.com

A

When column names need to be prefixed with table names, you can define table alias name and use them to prefix column names as shown in the following select statement:

mysql> SELECT l.id, l.url, r.comment FROM fyi_links l 
   INNER JOIN fyi_rates r ON l.id = r.id;
+-----+-------------------+-----------+
| id  | url               | comment   |
+-----+-------------------+-----------+
| 101 | dev.fyicenter.com | The best  |
| 102 | dba.fyicenter.com | Well done |
| 103 | sqa.fyicenter.com | Thumbs up |
+-----+-------------------+-----------+
3 rows in set (0.00 sec)

2007-05-11, 4759👍, 0💬

Can Multiple Columns Be Used in GROUP BY
Can Multiple Columns Be Used in GROUP BY? - MySQL FAQs - SQL SELECT Query Statements with GROUP BY If you want to break your output into smaller groups, if you specify multiple column names or expressions in the GROUP BY clause. Output in each group must satisfy a specific combination of the express... 2007-05-11, 4986👍, 0💬

How To Write an Inner Join with the WHERE Clause
How To Write an Inner Join with the WHERE Clause? - MySQL FAQs - SQL SELECT Statements with JOIN and Subqueries If you don't want to use the INNER JOIN ... ON clause to write an inner join, you can put the join condition in the WHERE clause as shown in the following query example: mysql> SELECT l.id... 2007-05-11, 4974👍, 0💬

How To Count Duplicated Values in a Column
How To Count Duplicated Values in a Column? - MySQL FAQs - SQL SELECT Query Statements with GROUP BY If you have a column with duplicated values, and you want to know what are those duplicated values are and how many duplicates are there for each of those values, you can use the GROUP BY ... HAVING ... 2007-05-11, 4867👍, 0💬

How To Write a Query with a Full Outer Join
How To Write a Query with a Full Outer Join? - MySQL FAQs - SQL SELECT Statements with JOIN and Subqueries There is no way to do full outer join in MySQL. It does not support this feature at the current MySQL release. 2007-05-11, 4806👍, 0💬

How To Define and Use Table Alias Names
How To Define and Use Table Alias Names? - MySQL FAQs - SQL SELECT Statements with JOIN and Subqueries When column names need to be prefixed with table names, you can define table alias name and use them to prefix column names as shown in the following select statement: mysql> SELECT l.id, l.url, r.... 2007-05-11, 4760👍, 0💬

How To Write a Query with a Right Outer Join
How To Write a Query with a Right Outer Join? - MySQL FAQs - SQL SELECT Statements with JOIN and Subqueries If you want to query from two tables with a right outer join, you can use the RIGHT OUTER JOIN ... ON clause in the FROM clause. The following query returns output with a right outer join from... 2007-05-11, 4759👍, 0💬

How To Name Query Output Columns
How To Name Query Output Columns? - MySQL FAQs - SQL SELECT Statements with JOIN and Subqueries Each column in the query output has a default name. If you don't like the default name, you can specify a new name for any column in the query output by using the AS clause. The following statement shows ... 2007-05-11, 4751👍, 0💬

Can Group Functions Be Used in the ORDER BY Clause
Can Group Functions Be Used in the ORDER BY Clause? - MySQL FAQs - SQL SELECT Query Statements with GROUP BY If the query output is aggregated as groups, you can sort the groups by using group functions in the ORDER BY clause. The following statement returns how many links were created in each year ... 2007-05-11, 4739👍, 0💬

How To Write a Query with a Left Outer Join
How To Write a Query with a Left Outer Join? - MySQL FAQs - SQL SELECT Statements with JOIN and Subqueries If you want to query from two tables with a left outer join, you can use the LEFT OUTER JOIN ... ON clause in the FROM clause. The following query returns output with a left outer join from two... 2007-05-11, 4559👍, 0💬

All rights in the contents of this web site are reserved by the individual author. fyicenter.com does not guarantee the truthfulness, accuracy, or reliability of any contents.