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myhelp:sql [2023/08/28 05:28] – [Get the lastest timestamp] ulrichmyhelp:sql [2024/10/05 07:51] (current) – [mySQL / MariaDB] ulrich
Line 11: Line 11:
 sqlite> UPDATE T_names SET birthyear=1997 WHERE name = 'Jack Doe'; sqlite> UPDATE T_names SET birthyear=1997 WHERE name = 'Jack Doe';
 sqlite> SELECT * FROM T_names LIMIT 1; sqlite> SELECT * FROM T_names LIMIT 1;
 +</code>
 +
 +====== mySQL / MariaDB ======
 +<code>
 +CREATE DATABASE IF NOT EXISTS meineDB;
 +CREATE USER 'benutzer'@'localhost' IDENTIFIED BY 'passwort';
 +GRANT ALL PRIVILEGES ON meineDB . * TO 'benutzer'@'localhost';
 +</code>
 +
 +Grant Access from remote IP (10.11.12.13)
 +<code>
 +GRANT ALL ON meineDB.* to 'benutzer'@'10.11.12.13' IDENTIFIED BY 'passwort' WITH GRANT OPTION;
 </code> </code>
  
Line 57: Line 69:
   - Restart the DBMS <code>systemctl restart postgresql.service</code>   - Restart the DBMS <code>systemctl restart postgresql.service</code>
  
-===== Get the lastest timestamp =====+===== A method to get the lastest timestamp =====
 From my point of view I've a good and a bad example From my point of view I've a good and a bad example
 +
 +The good example: 
 +<code>SELECT something FROM table 
 +WHERE time_stamp = (SELECT MAX(time_stamp) FROM table);</code>
  
 The bad example: The bad example:
-<code>SELECT something FROM table WHERE time_stamp = (SELECT time_stamp FROM table ORDER BY time_stamp DESC NULLS LAST LIMIT 1);</code>+<code>SELECT something FROM table  
 +WHERE time_stamp = (SELECT time_stamp FROM table ORDER BY time_stamp DESC NULLS LAST LIMIT 1);</code>
  
-The good example:  +===== Other usefull stuff ===== 
-<code>SELECT something FROM table WHERE time_stamp = (SELECT MAX(time_stamp) FROM table);</code>+Switch off the pages from CLI(shell) 
 +<code>sudo -u postgres psql -P pager=off -d database -c "SELECT something FROM table;"</code> 
 + 
 + 
 +Copy a SELECT to a CSV from CLI(shell) 
 +<code> 
 +sudo -u postgres psql -d database -c "COPY (SELECT  something, other_stuff FROM table  
 +GROUP BY somethingTO '/tmp/result.csv' WITH CSV HEADER;
 +</code>
  
 {{tag>[Good2Know]}} {{tag>[Good2Know]}}
myhelp/sql.1693200516.txt.gz · Last modified: by ulrich