Giving Names to Output Columns
mysql>
mysql> CREATE TABLE mail
-> (
-> t DATETIME, # when message was sent
-> senderUser CHAR(8), # sender (source user and host)
-> senderHost CHAR(20),
-> recipientUser CHAR(8), # recipient (destination user and host)
-> recipientHost CHAR(20),
-> size BIGINT, # message size in bytes
-> INDEX (t)
-> );
Query OK, 0 rows affected (0.01 sec)
mysql>
mysql> INSERT INTO mail (t,senderHost,senderUser,recipientHost,recipientUser,size)
-> VALUES
-> ('2010-05-11 10:15:08','saturn','barb','mars','tricia',58274),
-> ('2010-05-12 12:48:13','mars','tricia','venus','gene',194925),
-> ('2010-05-12 15:02:49','mars','phil','saturn','phil',1048),
-> ('2010-05-13 13:59:18','saturn','barb','venus','tricia',271),
-> ('2010-05-14 09:31:37','venus','gene','mars','barb',2291),
-> ('2010-05-14 11:52:17','mars','phil','saturn','tricia',5781),
-> ('2010-05-14 14:42:21','venus','barb','venus','barb',98151),
-> ('2010-05-14 17:03:01','saturn','tricia','venus','phil',2394482),
-> ('2010-05-15 07:17:48','mars','gene','saturn','gene',3824),
-> ('2010-05-15 08:50:57','venus','phil','venus','phil',978),
-> ('2010-05-15 10:25:52','mars','gene','saturn','tricia',998532),
-> ('2010-05-15 17:35:31','saturn','gene','mars','gene',3856),
-> ('2010-05-16 09:00:28','venus','gene','mars','barb',613),
-> ('2010-05-16 23:04:19','venus','phil','venus','barb',10294),
-> ('2010-05-17 12:49:23','mars','phil','saturn','tricia',873),
-> ('2010-05-19 22:21:51','saturn','gene','venus','gene',23992)
-> ;
Query OK, 16 rows affected (0.00 sec)
Records: 16 Duplicates: 0 Warnings: 0
mysql>
mysql> SELECT t, senderUser, senderHost, recipientUser, recipientHost, size FROM mail;
+---------------------+------------+------------+---------------+---------------+---------+
| t | senderUser | senderHost | recipientUser | recipientHost | size |
+---------------------+------------+------------+---------------+---------------+---------+
| 2010-05-11 10:15:08 | barb | saturn | tricia | mars | 58274 |
| 2010-05-12 12:48:13 | tricia | mars | gene | venus | 194925 |
| 2010-05-12 15:02:49 | phil | mars | phil | saturn | 1048 |
| 2010-05-13 13:59:18 | barb | saturn | tricia | venus | 271 |
| 2010-05-14 09:31:37 | gene | venus | barb | mars | 2291 |
| 2010-05-14 11:52:17 | phil | mars | tricia | saturn | 5781 |
| 2010-05-14 14:42:21 | barb | venus | barb | venus | 98151 |
| 2010-05-14 17:03:01 | tricia | saturn | phil | venus | 2394482 |
| 2010-05-15 07:17:48 | gene | mars | gene | saturn | 3824 |
| 2010-05-15 08:50:57 | phil | venus | phil | venus | 978 |
| 2010-05-15 10:25:52 | gene | mars | tricia | saturn | 998532 |
| 2010-05-15 17:35:31 | gene | saturn | gene | mars | 3856 |
| 2010-05-16 09:00:28 | gene | venus | barb | mars | 613 |
| 2010-05-16 23:04:19 | phil | venus | barb | venus | 10294 |
| 2010-05-17 12:49:23 | phil | mars | tricia | saturn | 873 |
| 2010-05-19 22:21:51 | gene | saturn | gene | venus | 23992 |
+---------------------+------------+------------+---------------+---------------+---------+
16 rows in set (0.00 sec)
mysql>
mysql> SELECT DATE_FORMAT(t,'%M %e, %Y') AS date_sent, senderUser, size FROM mail;
+--------------+------------+---------+
| date_sent | senderUser | size |
+--------------+------------+---------+
| May 11, 2010 | barb | 58274 |
| May 12, 2010 | tricia | 194925 |
| May 12, 2010 | phil | 1048 |
| May 13, 2010 | barb | 271 |
| May 14, 2010 | gene | 2291 |
| May 14, 2010 | phil | 5781 |
| May 14, 2010 | barb | 98151 |
| May 14, 2010 | tricia | 2394482 |
| May 15, 2010 | gene | 3824 |
| May 15, 2010 | phil | 978 |
| May 15, 2010 | gene | 998532 |
| May 15, 2010 | gene | 3856 |
| May 16, 2010 | gene | 613 |
| May 16, 2010 | phil | 10294 |
| May 17, 2010 | phil | 873 |
| May 19, 2010 | gene | 23992 |
+--------------+------------+---------+
16 rows in set (0.00 sec)
mysql>
mysql> drop table mail;
Query OK, 0 rows affected (0.00 sec)
mysql>
Related examples in the same category
| 1. | Important Column Attributes and Options | | |
| 2. | Drop a column | | |
| 3. | Chage column name | | |
| 4. | Change column definition | | |
| 5. | Change column data length | | |
| 6. | Change column data type | | |
| 7. | change column type and sequence in table | | |
| 8. | Modify a column | | |
| 9. | Adding a Column | | |
| 10. | Changing a Column Definition | | |
| 11. | Renaming a Table | | |
| 12. | Dropping a Column | | |
| 13. | Syntax for Adding a Column | | |
| 14. | Returns detailed information about all columns of the table tablename | | |
| 15. | Exchanging Rows and Columns | | |
| 16. | To copy only some of the columns, name the ones you want in the SELECT part of the statement. | | |
| 17. | To create columns in a different order than that in which they appear in the source table | | |
| 18. | Get information only for the co_2 column, you can't use this query: | | |
| 19. | The -e option specifies the query to execute, and -N tells MySQL not to write the row of column names that normally precedes query output. | | |
| 20. | Copying Only Selected Columns from a Table | | |
| 21. | Specifying Which Columns to Display | | |
| 22. | Aliases can be applied to any result set column, not just those that come from tables | | |
| 23. | Combining Columns to Construct Composite Values | | |
| 24. | Put the comparison expression in the output column list, perhaps including the values that you're comparing | | |
| 25. | Refer to the additional output column by position | | |
| 26. | Take everything but the rightmost two columns | | |
| 27. | Dropping, Adding, or Repositioning a Column | | |
| 28. | To indicate a column at a specific position within the table, either use FIRST to make it the first column, or | | |
| 29. | Changing a Column Definition or Name | | |
| 30. | After the CHANGE keyword, you name the column you want to change, then specify the new definition, which inclu | | |
| 31. | Changing a Column's Default Value | | |
| 32. | Information only about a single column, use a LIKE clause that matches the column name | | |
| 33. | -d option specifies a field delimiter of : and the -f option indicates that you want to cut column one and all | | |
| 34. | Add a sequence column named id to the table | | |
| 35. | Give each table a short alias and refer to table columns using the aliases: | | |
| 36. | To exclude them, provide a column output list that names specifically only those columns | | |
| 37. | To produce additional columns showing the total and average values of the books for each author in the author | | |
| 38. | CREATE TABLE statement provides an example of a TEXT column named DescriptionDoc | | |
| 39. | Create the Catalog table and includes two NOT NULL columns | | |
| 40. | Reference a column | | |
| 41. | Add and drop columns | | |
| 42. | Giving Columns a New Heading with AS | | |
| 43. | Alias column with spaces | | |
| 44. | Insert data without column names | | |
| 45. | Column definition with modifiers | | |
| 46. | Sort by column name | | |
| 47. | Sort more than one columns | | |
| 48. | Get the descriptive data of the columns belonging to the PLAYERS table | | |
| 49. | A table contains only one column. | | |
| 50. | A column definition may include options to define the column data more precisely. | | |
| 51. | More complex tables have multiple columns | | |
| 52. | Adding and Dropping Columns | | |
| 53. | Modifying Existing Columns | | |
| 54. | Change the LastName column from CHAR(30) to CHAR(40) without renaming the column | | |
| 55. | Column Types | | |
| 56. | NULL Values and Column Definitions | | |
| 57. | Use single quote with char type column | | |
| 58. | Column alias with underscore | | |
| 59. | Using Case clause to show meaningful value for column | | |
| 60. | Select all columns from a table inside another database | | |
| 61. | Concatenate columns | | |
| 62. | Using qulified column name | | |
| 63. | Compare two columns together | | |
| 64. | Compare two columns and yield two values | | |
| 65. | Column sequence in insert statemenet | | |
| 66. | Change column type and settings during table copying | | |
| 67. | Enlarge column during table copying | | |
| 68. | Set column to use default value | | |
| 69. | Get default value from a column | | |
| 70. | Table column with comments | | |
| 71. | Check table column settings | | |
| 72. | Unique modifier for column definition | | |
| 73. | Indicate unique after column definition | | |
| 74. | Check column value | | |
| 75. | Set type column | | |
| 76. | To disallow NULL values in any of the columns, add NOT NULL to the definition of each one. | | |