NAME

MySperql - Module to simplify DBI MySQL statements

SYNOPSIS

  use DBIx::MySperql qw(DBConnect SQLExec $dbh);
    
  $dbh = &DBConnect(%parameters);
  
  $return = &SQLExec($sql, $type, \%parameters);
  @return = &SQLExec($sql, $type, \%parameters);
  
  $sth = &SQLExecute($sql, %parameters);
  $sth = &SQLParse($test, %parameters);
  $ref = &SQLFetch($sth, $type);

DESCRIPTION

MySperql enables one line sql statements when using perl with DBI and MySQL. It supports single or multiple connections to both local and remote databases.

Using the module requires that you understand: 1) how to write the SQL statments you need 2) perl lists ('@') and references ('\')

The second concept is necessary to both understand the "$type" parameter and handle the results. The types are strings that represent the data type expected to be returned. They logically match the data structure returned: '@' is a one-row list, '\@' is a one row reference to a list, and '\@@' is a (potentially) multi-row reference. See below for included examples of each type.

This module was originally created as a database library in 2001 by Roger Hall (Little Rock, AR) and Eric Goldbrenner (San Francisco, CA).

(Thanks again Eric! :)

FUNCTIONS

• DBConnect

    $dbh = DBConnect(database => $db, host => $host, user => $user, pass => $pass);

  The parameters hash should include the following minimum keys for DBI connections: database, host, user, pass. The database must exist on the host, and the user must have permissions using the pass. Note that the hash is not referenced.

  The handle is both saved in the global variable $dbh and also returned by the function, so DBConnect may be called like this:

    my $dbh = DBConnect(%parameters);

  or this:

    DBConnect(%parameters);

  but it must be called before SQLExec().

  You might use the former method to open multiple connections (i.e. $dbh1, $dbh2) and the latter for more simple workflows. When using multiple connections, remember to assign the handle you want back to the global $dbh variable before using SQLExec. See "Using Multiple MySQL Connections" below.

• SQLExec

    $ref = SQLExec($sql, $type, %parms);

  This is the workhorse statement, and for most applications, the only "SQLX" function you will use.

  A typical statement might be:

    $ref = SQLExec($sql, '\@@');

  with other examples below.

   Parm: $sql    a sql statement string
         $type   a character string that determines 
                 the data type of the return:
                 \@@   reference to an array of arrays (all 
                       rows fetch)
                 \@    reference to an array (one row fetch)
                 @     an array (one row fetch)
                 \%    reference to a hash with field names
                       as keys (one row fetch)
                 $sth  statement handle
                 other scalar value
         %parms  database level parameters
   Note: Remember to single-quote the $type character
         string (because "$sth" != '$sth')!

• SQLExecute

    $sth = SQLExecute($sql, %parameters);

  Handles the parsing, binding and execution of a sql statement.

• SQLFetch

    $ref = SQLFetch($sth, $type);

  Fetches rows based on $type specified.

   Parm: $sth    a valid dbi statement handle
         $type   a string that determines the type of return
                 \@@   reference to an array of arrays (all 
                       rows fetch)
                 \@    reference to an array (one row fetch)
                 @     an array (one row fetch)
                 \%    reference to a hash with field names
                       as keys (one row fetch)
                 $sth  statement handle
                 other scalar value

• SQLParse

    $sth = SQLParse($test, %parameters);

  Encapsulates DBI prepare() function.

   Parm: $test is either a(n) sql statement with zero
         or more named parameters or an active 
         statement handle
         %parameters is a hash with parameter names 
         as keys and parameter values as values. 
         Only the word part of the names should be 
         used as keys (ie leave off the leading ':').
   Note: 1. SQLParse is responsible for making sure an 
         active global database handle ($dbh) exists
         2. SQLParse prepare()s the statement to check 
         for parsing errors.

• GetRowCount

    $count = GetRowCount($ref);

  Returns the row count of a record object.

   Parm: $ref    a reference to a table (array of arrays)
         $count  the number of rows
   Note: Handles Scalars, Arrays, and all references.

• GetColumnCount

    $count = GetColumnCount($ref);

  Returns the column count of a record object.

   Parm: $ref    a reference to a table (array of arrays)
         $count  the number of columns
   Note: Handles Scalars, Arrays, and all references.

• GetFieldNames

    @fields = GetFieldNames($sth);

  Returns the names of the table columns.

   Parm: $sth    a valid dbi statement handle
         @fields the returned list of field names
   

• IsHandle

    $boolean = IsHandle($test);

  Tests if an object is a statement handle. Used to tell handles and sql strings apart.

    if (&IsHandle($test)) { ... }
  
   Parm: $test   the handle or string

EXAMPLES

• Top-Of-The-File Requirements

    use DBIx::MySperql qw(DBConnect SQLExec $dbh);
    
    # Open connect
    $dbh = DBConnect(database => 'mydb', host => 'localhost', user => 'myuser', pass => 'mypass');
    

• Insert a record

    # Insert record
    SQLExec("insert into table(field1, field2) values ('$field1', '$field2')");

• Update a record

    # Update record
    SQLExec("update table set field1 = '$field1' where id = $id");

• Delete a record

    # Delete record
    SQLExec("delete from table where id = $id");

• Select single record

    # Get record
    $sql = "select * from table where id = $id";
    my ($id, $field1, $field2) = SQLExec($sql, '@');
    

• Select table with fields-on-the-fly

    use DBIx::MySperql qw(DBConnect SQLExec GetFieldNames);
  
    # Get handle
    $sql = "select * from table where id = $id";
    $sth = SQLExec($sql, '$sth');
    
    # Get field names
    @fields = GetFieldNames($sth);
  
    # Get records
    $ref = SQLExec($sth, '@');
    

• Select multiple records

    # Get table
    $sql = "select * from table";
    $rows = SQLExec($sql, '\@@');
    foreach $row (@$rows) {
          my ($id, $field1, $field2) = @$row;
    
          print "($id) $field1 = $field2\n";
    }
    

• Using multiple MySQL connections

    # Open the first connection
    $dbh = my $dbh1 = DBConnect(%parms1);
  
    # Make statements
    $sql = "...
    &SQLExec($sql ...);
  
    # Open an additional connection
    $dbh = my $dbh2 = DBConnect(%parms2);
  
    # Make statements
    $sql = "...
    &SQLExec($sql ...);
  
    # Return to previous connection
    $dbh = $dbh1;
  
    # Make statements
    $sql = "...
    &SQLExec($sql ...);
  
    ...

EXPORT

  $dbh      # Database Handle

SEE ALSO

http://www.iosea.com/mysperql

AUTHOR

Roger Hall <roger@iosea.com>

COPYRIGHT AND LICENSE

Copyleft (C) 2007 by Roger Hall

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.5 or, at your option, any later version of Perl 5 you may have available.