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Data Retrieval

Data Retrieval

Owned by Daniel Kim (Unlicensed)
Feb 22, 2023

You can retrieve data in ANSI standard SQL.

The following example shows a search without creating an index.

In other words, the last input data is outputed first.

For more information, see the SELECT section of the SQL Reference.

Basic access

SELECT * FROM table_name;

Index

Mach> SELECT * FROM mach_log;
DEVICE          TM                              TEMP        
----------------------------------------------------------------
MSG                                                                               
------------------------------------------------------------------------------------
192.168.0.1     NULL                            NULL        
NULL                                                                              
192.168.0.2     2014-06-15 19:50:03 484:382:010 82          
error code = 20, critical warning                                                 
192.168.0.2     2014-06-15 19:50:03 484:382:008 57          
error code = 20                                                                   
192.168.0.1     2014-06-15 19:50:03 484:382:006 99          
error code = 10, critical bug                                                     
192.168.0.1     2014-06-15 19:50:03 484:382:004 55          
error code = 10                                                                   
192.168.0.2     2014-06-15 19:50:03 484:382:002 31        
normal state                                                                      
192.168.0.1     2014-06-15 19:50:03 484:382:000 32          
normal state                                                                      
[7] row(s) selected.
Mach>


View Conditional Clause

SELECT column_name,column_name
FROM table_name
WHERE column_name operator value;
Mach> SELECT * FROM mach_log WHERE device = '192.168.0.1';
DEVICE          TM                              TEMP        
----------------------------------------------------------------
MSG                                                                               
------------------------------------------------------------------------------------
192.168.0.1     NULL                            NULL        
NULL                                                                              
192.168.0.1     2014-06-15 19:50:36 488:663:006 99          
error code = 10, critical bug                                                     
192.168.0.1     2014-06-15 19:50:36 488:663:004 55          
error code = 10                                                                   
192.168.0.1     2014-06-15 19:50:36 488:663:000 32          
normal state                                                                      
[4] row(s) selected.

Mach> SELECT * FROM mach_log WHERE device = '192.168.0.1' AND temp > 30 AND temp < 50;
DEVICE          TM                              TEMP        
----------------------------------------------------------------
MSG                                                                               
------------------------------------------------------------------------------------
192.168.0.1     2014-06-15 19:50:36 488:663:000 32          
normal state                                                                      
[1] row(s) selected.

Mach> SELECT * FROM mach_log where device > '192.168.0.1';
DEVICE          TM                              TEMP        
----------------------------------------------------------------
MSG                                                                               
------------------------------------------------------------------------------------
192.168.0.2     2014-06-15 19:50:36 488:663:010 82          
error code = 20, critical warning                                                 
192.168.0.2     2014-06-15 19:50:36 488:663:008 57          
error code = 20                                                                   
192.168.0.2     2014-06-15 19:50:36 488:663:002 31          
normal state                                                                      
[3] row(s) selected.

Mach> SELECT * FROM mach_log WHERE msg LIKE '%error%';
DEVICE          TM                              TEMP        
----------------------------------------------------------------
MSG                                                                               
------------------------------------------------------------------------------------
192.168.0.2     2014-06-15 19:50:36 488:663:010 82          
error code = 20, critical warning                                                 
192.168.0.2     2014-06-15 19:50:36 488:663:008 57          
error code = 20                                                                   
192.168.0.1     2014-06-15 19:50:36 488:663:006 99          
error code = 10, critical bug                                                     
192.168.0.1     2014-06-15 19:50:36 488:663:004 55          
error code = 10                                                                   
[4] row(s) selected.

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