MSQL Perl interface commands
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Making Connections |
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$dbh = Msql->connect($host)
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dbh gets connection information from host
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$dbh->selectdb("database")
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dbh also gets the dtabase informatino
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$dbh = Msql->connect($host,"database")
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dbh connects to host with database 'test'
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Database & Server Information |
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@databaselist = $dbh->listdbs
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@databaselist gets all the current databases from the server selected in $dbh
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@tablelist = $dbh->listtables
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@tablelist gets all the tables from the database selected in $dbh
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$fields = $sth->numfields
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$fields gets the number of rows in the database determined by $dbh and the table specified in the query
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$sth->name
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Returns array reference to the field names.
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@fieldnum{@{$sth->name}} = 0..@{$sth->name}-1
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%fieldname gets (id => 0, num => 1, val => 2)
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$dbh->query("drop table $newtable")
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Drop table example
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Msql->getserverinfo
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Returns server version
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Msql->errmsg =~ /error/
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Checks Msql error (can also be checked with eval and $@
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Composing Queries |
$query = qq{
create table $newtable (
id char(3),
num char(4) not null,
val char (5))
}
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$query gets a query statement
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$dbh->query($query)
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performs the query $query on the database selected by $dbh
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$query = qq{
insert into $newtable values ('one', 'two', 'three')
}
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Another query example
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$query = "select * from $newtable"
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Another query example - finds everything
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$sth = $dbh->query($query)
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$sth gets a reference to the query result
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$sth = $dbh->query("select * from $newtable
where id = 'one'")
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Another query example. $sth gets a reference to the result
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Working with Query Results |
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@row = $sth->fetchrow
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@row gets a value for each field in the fecthrow result. e.g. ('one', 'two', 'three')
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$rows = $sth->numrows
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$rows gets the number of rows in the database determined by $dbh and the table specified in the query
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$sth->length
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Returns array reference to the field lengths. e.g. @{$sth->length} is ('3', '4', '5')
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$sth->table
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Returns table array reference
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$sth->type
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Reference to the data type. Used to compare with the exported functions (CHAR_TYPE, NUM_TYPE and REAL_TYPE)
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$sth->type->is_not_null
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Returns definedness information
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$sth->type->is_pri_key
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Returns indexing information
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$sth->fetchrow())
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Returns the next rownumber - e.w. while (@row = $sth->fetchrow()) {do something}
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$sth->dataseek(parameter)
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E.G. - $sth->dataseek(0) starts at the top of the query again.
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undef ($sth)
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frees memory associated with $sth
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$sth_query->fetchhash
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Fetchhash puts the contents of a row into a hash
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This is designed to be a quick reference to the various msqlPerl commands.
Send any questions or comments to sjohnson@websetter.com
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