Hi,
I am a new learner of join command. Some result really make me confused.
Please kindly help me.
input:
file1:
LEO oracle engineer 210375
P.Jones Office Runner ID897
L.Clip Personl Chief ID982
S.Round UNIX admin ID6
file2:
Dept2C ID897 6 years
Dept5Z ID982 1 year
Dept3S ID6 2... (1 Reply)
Hi,
This is the second time for me to ask question about join command, i really feel sorry and shame. But it is very difficult to me.
Please kindly help on how to get my desired result(i give it below), in additon to tell me how, please also kindly tell me why.
Thanks in advanced.
... (1 Reply)
example sql:
select a.a1,b.b1,c.c1,d.d1,e.e1
from a
left outer join b on a.x=b.x
left outer join c on b.y=c.y
left outer join d on d.z=a.z
inner join a.t=e.t
I know how single outer or inner join works in sql.
But I don't really understand when there are multiple of them.
can... (0 Replies)
Hello,
My apologies if this has been posted elsewhere, I have had a look at several threads but I am still confused how to use these functions. I have two files, each with 5 columns:
File A: (tab-delimited)
PDB CHAIN Start End Fragment
1avq A 171 176 awyfan
1avq A 172 177 wyfany
1c7k A 2 7... (3 Replies)
Hi,
I have 20 tab delimited text files that have a common column (column 1). The files are named GSM1.txt through GSM20.txt. Each file has 3 columns (2 other columns in addition to the first common column).
I want to write a script to join the files by the first common column so that in the... (5 Replies)
Hello,
This post is already here but want to do this with another way
Merge multiples files with multiples duplicates keys by filling "NULL" the void columns for anothers joinning files
file1.csv:
1|abc
1|def
2|ghi
2|jkl
3|mno
3|pqr
file2.csv:
1|123|jojo
1|NULL|bibi... (2 Replies)
Discussion started by: yjacknewton
2 Replies
LEARN ABOUT DEBIAN
alzabo::column
Alzabo::Column(3pm) User Contributed Perl Documentation Alzabo::Column(3pm)NAME
Alzabo::Column - Column objects
SYNOPSIS
use Alzabo::Column;
foreach my $c ($table->columns)
{
print $c->name;
}
DESCRIPTION
This object represents a column. It holds data specific to a column.
METHODS
table
Returns the table object to which this column belongs.
name
Returns the column's name as a string.
nullable
Returns a boolean value indicating whether or not NULLs are allowed in this column.
attributes
A column's attributes are strings describing the column (for example, valid attributes in MySQL are 'UNSIGNED' or 'ZEROFILL'.
This method returns a list of strings of such strings.
has_attribute
This method can be used to test whether or not a column has a particular attribute. By default, the check is case-insensitive.
It takes the following parameters:
* attribute => $attribute
* case_sensitive => 0 or 1 (defaults to 0)
It returns a boolean value indicating whether or not the column has this particular attribute.
type
Returns the column's type as a string.
sequenced
The meaning of a sequenced column varies from one RDBMS to another. In those with sequences, it means that a sequence is created and that
values for this column will be drawn from it for inserts into this table. In databases without sequences, the nearest analog for a
sequence is used (in MySQL the column is given the AUTO_INCREMENT attribute, in Sybase the identity attribute).
In general, this only has meaning for the primary key column of a table with a single column primary key. Setting the column as sequenced
means its value never has to be provided to when calling "Alzabo::Runtime::Table->insert".
Returns a boolean value indicating whether or not this column is sequenced.
default
Returns the default value of the column as a string, or undef if there is no default.
default_is_raw
Returns true if the default is intended to be provided to the DBMS as-is, without quoting, fore example "NOW()" or "current_timestamp".
length
Returns the length attribute of the column, or undef if there is none.
precision
Returns the precision attribute of the column, or undef if there is none.
is_primary_key
Returns a boolean value indicating whether or not this column is part of its table's primary key.
is_numeric
Returns a boolean value indicating whether the column is a numeric type column.
is_integer
Returns a boolean value indicating whether the column is a numeric type column.
is_floating_point
Returns a boolean value indicating whether the column is a numeric type column.
is_character
Returns a boolean value indicating whether the column is a character type column.
This is true only for any columns which are defined to hold text data, regardless of size.
is_date
Returns a boolean value indicating whether the column is a date type column.
is_datetime
Returns a boolean value indicating whether the column is a datetime type column.
is_time
Returns a boolean value indicating whether the column is a time type column.
is_time_interval
Returns a boolean value indicating whether the column is a time interval type column.
is_blob
Returns a boolean value indicating whether the column is a blob column.
This is true for any columns defined to hold binary data, regardless of size.
generic_type
This methods returns one of the following strings:
integer
floating_point
character
date
datetime
time
blob
unknown
definition
The definition object is very rarely of interest. Use the "type()" method if you are only interested in the column's type.
This methods returns the "Alzabo::ColumnDefinition" object which holds this column's type information.
comment
Returns the comment associated with the column object, if any.
AUTHOR
Dave Rolsky, <autarch@urth.org>
perl v5.8.8 2007-12-23 Alzabo::Column(3pm)