MySQL CLI

 Command Format and Usage

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* Environment variables has lower precedence over command-line options 

* "-" and "_" can be interchanged 

  example: --skip-grant-tables and --skip_grant_tables are the same 

* Last option takes precedence 

  example: shell> mysql --column-names --skip-column-names 

* Long form options can be written as: --long-option=value 

* For long options which don't have a default value, "=" is not required 

  e.g: mysql --host tonfisk --user jon 

* Options having default values always required "=" sign 

  e.g: mysqld_safe --log-error=my-errors &  # default value is `hostname.err` 

* Here are some invalid formats: 

    mysql --host 85.224.35.45 --user 

    mysql --host --user jon 

*  

 

Program Options Modifier 

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Options with same effect	--disable-column-names  --skip-column-names  --column-names=0    or    --column-names  --enable-column-names  --column-names=1
Ignoring non-existent  options	Adding "--loose" prior to an option makes mysql ignore non-existent options.    Example, this provides a valid option:    [ansible@mysql ~]$ mysql --loose-skip-column-names -e "select * from pets.pet;"  +----------+-----------+---------+------+------------+------------+  | Whistler |      Gwen |    bird | NULL | 1997-12-09 |       NULL |  |   Gunner |      Mark |     dog |    m | 1992-01-14 |       NULL |  |    Heath | Stephanie | penguin |    m | 2001-12-12 |       NULL |  |  Winnona | Stephanie |     dog |    m | 2009-03-18 |       NULL |  |   Hunter | Stephanie |    fish |    f | 1997-09-21 |       NULL |  | Splitter |      Gwen |    fish |    m | 1996-01-12 | 1999-03-04 |  |   Styder |      Gwen |    fish |    f | 2018-05-17 |       NULL |  +----------+-----------+---------+------+------------+------------+    While this one doesn't but MySQL just ignores it.    [ansible@mysql ~]$ mysql --loose-skip-columns-names -e "select * from pets.pet;"  mysql: [Warning] unknown option '--loose-skip-columns-names'  +----------+-----------+---------+------+------------+------------+  | name     | owner     | species | sex  | birth      | death      |  +----------+-----------+---------+------+------------+------------+  | Whistler | Gwen      | bird    | NULL | 1997-12-09 | NULL       |  | Gunner   | Mark      | dog     | m    | 1992-01-14 | NULL       |  | Heath    | Stephanie | penguin | m    | 2001-12-12 | NULL       |  | Winnona  | Stephanie | dog     | m    | 2009-03-18 | NULL       |  | Hunter   | Stephanie | fish    | f    | 1997-09-21 | NULL       |  | Splitter | Gwen      | fish    | m    | 1996-01-12 | 1999-03-04 |  | Styder   | Gwen      | fish    | f    | 2018-05-17 | NULL       |  +----------+-----------+---------+------+------------+------------+  [ansible@mysql ~]$    This is helpful if you are executing a command over different versions of MySQL.  That guarantees that your command will not terminate when an invalid options  is detected.
Setting max sizes	"--maximum-max_heap_table_size=32M" prevents any client from making the heap  table size limit larger than 32M.