IT民工

[size=medium][align=center][b]Sorting Query Results[/b][/align][/size] [size=small][b]1.Sorting by Variable-Length Substrings[/b][/size] select id,left(substring(id,4),char_length(substring(id,4)-...

[size=medium][align=center][b]Generating Summaries[/b][/align][/size] [size=small][b]1.Using DISTINCT to Eliminate Duplicates[/b][/size] select count(DISTINCT name) from driver_log; count(DISTINC...

[size=medium][align=center][b]Using the mysql Client Program[/b][/align][/size] [size=small][b]1.Setting Up a MySQL User Account[/b][/size] GRANT ON TO [IDENTIFIED BY ""] [WITH GRANT OPTION]; ...

[size=medium][align=center][b]Selecting Data from Tables[/b][/align][/size] [size=small][b]1.Combining Columns to Construct Composite Values[/b][/size] select date_format(monthname(t),'',dayofmont...

[size=medium][align=center][b]Table Management[/b][/align][/size] [size=small][b]1.Cloning a Table[/b][/size] create table [i]new_table[/i] like [i]original_table[/i]; insert into [i]new_table[/i...

[size=medium][align=center][b]Working with Strings[/b][/align][/size] [size=small][b]1.Converting the Lettercases of a String[/b][/size] select thing,upper(thing),lower(thing) from limbs; upper()...

[size=medium][align=center][b]Working with Dates and Times[/b][/align][/size] [size=small][b]1.Changing MySQL's Date Format[/b][/size] select d,date_format(d,'%m %d,%y') from date_val; 使用date_for...