--- loncom/interface/lonmysql.pm 2002/07/28 18:21:13 1.2 +++ loncom/interface/lonmysql.pm 2004/07/26 19:36:21 1.23 @@ -1,7 +1,7 @@ # The LearningOnline Network with CAPA # MySQL utility functions # -# $Id: lonmysql.pm,v 1.2 2002/07/28 18:21:13 matthew Exp $ +# $Id: lonmysql.pm,v 1.23 2004/07/26 19:36:21 matthew Exp $ # # Copyright Michigan State University Board of Trustees # @@ -31,7 +31,25 @@ package Apache::lonmysql; use strict; use DBI; -use Apache::lonnet(); +use POSIX qw(strftime mktime); + +my $mysqluser; +my $mysqlpassword; + +sub set_mysql_user_and_password { + # If we are running under Apache and LONCAPA, use the LON-CAPA + # user and password. Otherwise...? ? ? ? + ($mysqluser,$mysqlpassword) = @_; + if (! defined($mysqluser) || ! defined($mysqlpassword)) { + if (! eval 'require Apache::lonnet();') { + $mysqluser = 'www'; + $mysqlpassword = $Apache::lonnet::perlvar{'lonSqlAccess'}; + } else { + $mysqluser = ''; + $mysqlpassword = ''; + } + } +} ###################################################################### ###################################################################### @@ -71,20 +89,19 @@ To create a table, you need a descriptio for &create_table for a description of what is needed. $table_id = &create_table({ - columns => { - id => { - type => 'INT', - restrictions => 'NOT NULL', - primary_key => 'yes', - auto_inc => 'yes' - } - verbage => { type => 'TEXT' }, - idx_verbage => { type => 'FULLTEXT', - target => 'verbage' - } - }, - column_order => [qw/id verbage idx_verbage/] - }); + id => 'tableid', # usually you will use the returned id + columns => ( + { name => 'id', + type => 'INT', + restrictions => 'NOT NULL', + primary_key => 'yes', + auto_inc => 'yes' + }, + { name => 'verbage', + type => 'TEXT' }, + ), + fulltext => [qw/verbage/], + }); The above command will create a table with two columns, 'id' and 'verbage'. @@ -94,7 +111,7 @@ The above command will create a table wi text string to be stored. Depending on your intentions for this database, setting restrictions => 'NOT NULL' may help you avoid storing empty data. -'idx_verbage' sets up the 'verbage' column for 'FULLTEXT' searching. +the fulltext element sets up the 'verbage' column for 'FULLTEXT' searching. @@ -120,10 +137,6 @@ Since the above table was created with t autoincrement, providing a value is unnecessary even though the column was marked as 'NOT NULL'. -In the future an array of arrays or hashes may be supported, but currently -the system only performs one insert at a time. Given the nature of this -interface, transactions (locking of the table) are not supported. - =item Retrieving rows @@ -168,24 +181,83 @@ The following entries are allowed in the =over 4 -=item columns +=item Name + +Table name. + +=item Type + +The type of table, typically MyISAM. + +=item Row_format + +Describes how rows should be stored in the table. DYNAMIC or STATIC. + +=item Create_time + +The date of the tables creation. + +=item Update_time + +The date of the last modification of the table. + +=item Check_time + +Usually NULL. + +=item Avg_row_length + +The average length of the rows. -The columns information required by &create_table. +=item Data_length -=item column_order +The length of the data stored in the table (bytes) -Reference to an array containing the order of columns in the table. +=item Max_data_length -=item table_info +The maximum possible size of the table (bytes). -Set to the results of &get_table_info. +=item Index_length -=item row_insert_sth +The length of the index for the table (bytes) + +=item Data_free + +I have no idea what this is. + +=item Comment + +The comment associated with the table. + +=item Rows + +The number of rows in the table. + +=item Auto_increment + +The value of the next auto_increment field. + +=item Create_options + +I have no idea. + +=item Col_order + +an array reference which holds the order of columns in the table. + +=item row_insert_sth + +The statement handler for row inserts. + +=item row_replace_sth The statement handler for row inserts. =back +Col_order and row_insert_sth are kept internally by lonmysql and are not +part of the usual MySQL table information. + =cut ################################################## @@ -274,24 +346,20 @@ connection is established. ############################### sub connect_to_db { return 1 if ($dbh); - if (! ($dbh = DBI->connect("DBI:mysql:loncapa","www", - $Apache::lonnet::perlvar{'lonSqlAccess'}, + if (! defined($mysqluser) || ! defined($mysqlpassword)) { + &set_mysql_user_and_password(); + } + if (! ($dbh = DBI->connect("DBI:mysql:loncapa",$mysqluser,$mysqlpassword, { RaiseError=>0,PrintError=>0}))) { $debugstring = "Unable to connect to loncapa database."; - if ($dbh->err) { + if (! defined($dbh)) { + $debugstring = "Unable to connect to loncapa database."; + $errorstring = "dbh was undefined."; + } elsif ($dbh->err) { $errorstring = "Connection error: ".$dbh->errstr; } return undef; } - # The code below will let us switch to a different database. - # my $db_command = "USE $db;"; - # my $sth = $dbh->prepare($db_command); - # $sth->execute(); - # if ($sth->err) { - # # Unable to use the database. Interesting... - # $dbh->disconnect; - # return undef; - # } $debugstring = "Successfully connected to loncapa database."; return 1; } @@ -300,6 +368,36 @@ sub connect_to_db { =pod +=item &verify_sql_connection() + +Inputs: none. + +Returns: 0 (failure) or 1 (success) + +Checks to make sure the database can be connected to. It does not +initialize anything in the lonmysql package. + +=cut + +############################### +sub verify_sql_connection { + if (! defined($mysqluser) || ! defined($mysqlpassword)) { + &set_mysql_user_and_password(); + } + my $connection; + if (! ($connection = DBI->connect("DBI:mysql:loncapa", + $mysqluser,$mysqlpassword, + { RaiseError=>0,PrintError=>0}))) { + return 0; + } + undef($connection); + return 1; +} + +############################### + +=pod + =item &disconnect_from_db() Inputs: none. @@ -319,6 +417,9 @@ sub disconnect_from_db { if (exists($Tables{$_}->{'row_insert_sth'})) { delete($Tables{$_}->{'row_insert_sth'}); } + if (exists($Tables{$_}->{'row_replace_sth'})) { + delete($Tables{$_}->{'row_replace_sth'}); + } } $dbh->disconnect if ($dbh); $debugstring = "Disconnected from database."; @@ -334,20 +435,36 @@ sub disconnect_from_db { Input: table identifier -Returns: the number of rows in the given table. +Returns: the number of rows in the given table, undef on error. =cut ############################### sub number_of_rows { my ($table_id) = @_; - # Update the table information - my %Table_Info = %{&get_table_info($table_id)}; - # return the number of rows. - if (defined(%Table_Info)) { - return $Table_Info{'Rows'}; - } - return undef; + return undef if (! defined(&connect_to_db())); + return undef if (! defined(&update_table_info($table_id))); + return $Tables{&translate_id($table_id)}->{'Rows'}; +} +############################### + +=pod + +=item &get_dbh() + +Input: nothing + +Returns: the database handler, or undef on error. + +This routine allows the programmer to gain access to the database handler. +Be careful. + +=cut + +############################### +sub get_dbh { + return undef if (! defined(&connect_to_db())); + return $dbh; } ############################### @@ -388,14 +505,16 @@ sub get_debug { =pod -=item &get_table_info($table_id) +=item &update_table_info() Inputs: table id -Returns: undef or a pointer to a hash of data about a table. +Returns: undef on error, 1 on success. + +&update_table_info updates the %Tables hash with current information about +the given table. -&get_table_info returns all of the information it can about a table in the -form of a hash. Currently the fields in the hash are: +The default MySQL table status fields are: Name Type Row_format Max_data_length Index_length Data_free @@ -403,14 +522,24 @@ form of a hash. Currently the fields in Avg_row_length Data_length Comment Rows Auto_increment Create_options +Additionally, "Col_order" is updated as well. + =cut ############################### -sub get_table_info { +sub update_table_info { my ($table_id) = @_; + return undef if (! defined(&connect_to_db())); + my $table_status = &check_table($table_id); + return undef if (! defined($table_status)); + if (! $table_status) { + $errorstring = "table $table_id does not exist."; + return undef; + } my $tablename = &translate_id($table_id); - return undef if (! &check_table($table_id)); - my %tableinfo; + # + # Get MySQLs table status information. + # my @tabledesc = qw/ Name Type Row_format Rows Avg_row_length Data_length Max_data_length Index_length Data_free Auto_increment @@ -419,73 +548,167 @@ sub get_table_info { my $sth = $dbh->prepare($db_command); $sth->execute(); if ($sth->err) { - # Unable to use the database. Interesting... $errorstring = "$dbh ATTEMPTED:\n".$db_command."\nRESULTING ERROR:\n". $sth->errstr; - $dbh->disconnect; + &disconnect_from_db(); return undef; } # my @info=$sth->fetchrow_array; for (my $i=0;$i<= $#info ; $i++) { - $tableinfo{$tabledesc[$i]}= $info[$i]; + $Tables{$tablename}->{$tabledesc[$i]}= $info[$i]; + } + # + # Determine the column order + # + $db_command = "DESCRIBE $tablename"; + $sth = $dbh->prepare($db_command); + $sth->execute(); + if ($sth->err) { + $errorstring = "$dbh ATTEMPTED:\n".$db_command."\nRESULTING ERROR:\n". + $sth->errstr; + &disconnect_from_db(); + return undef; + } + my $aref=$sth->fetchall_arrayref; + $Tables{$tablename}->{'Col_order'}=[]; # Clear values. + # The values we want are the 'Field' entries, the first column. + for (my $i=0;$i< @$aref ; $i++) { + push @{$Tables{$tablename}->{'Col_order'}},$aref->[$i]->[0]; } # $debugstring = "Retrieved table info for $tablename"; - return \%tableinfo; + return 1; +} +############################### + +=pod + +=item &col_order() + +Inputs: table id + +Returns: array with column order + +=cut + + +sub col_order { + my $table_id=shift; + if (&update_table_info($table_id)) { + return @{$Tables{$table_id}->{'Col_order'}}; + } else { + return (); + } } ############################### =pod -=item &create_table +=item &create_table() Inputs: - table description + table description, see &build_table_creation_request +Returns: + undef on error, table id on success. + +=cut + +############################### +sub create_table { + return undef if (!defined(&connect_to_db($dbh))); + my ($table_des)=@_; + my $request = &build_table_creation_request($table_des); + # + # Execute the request to create the table + ############################################# + my $count = $dbh->do($request); + if (! defined($count)) { + $errorstring = "$dbh ATTEMPTED:\n".$request."\nRESULTING ERROR:\n". + $dbh->errstr(); + return undef; + } + # + # Set up the internal bookkeeping + ############################################# + my $table_id; + if (exists($table_des->{'id'})) { + $table_id = $table_des->{'id'}; + } else { + $table_id = &get_new_table_id(); + } + my $tablename = &translate_id($table_id); + delete($Tables{$tablename}) if (exists($Tables{$tablename})); + return undef if (! defined(&update_table_info($table_id))); + $debugstring = "Created table $tablename at time ".time. + " with request\n$request"; + return $table_id; +} + +############################### -Input formats: +=pod + +=item build_table_creation_request + +Input: table description table description = { permanent => 'yes' or 'no', - columns => { - colA => { - type => mysql type, - restrictions => 'NOT NULL' or empty, - primary_key => 'yes' or empty, - auto_inc => 'yes' or empty, - target => 'colB' (only if type eq 'FULLTEXT'), - } - colB => { .. } - colZ => { .. } - }, - column_order => [ colA, colB, ..., colZ], + columns => [ + { name => 'colA', + type => mysql type, + restrictions => 'NOT NULL' or empty, + primary_key => 'yes' or empty, + auto_inc => 'yes' or empty, + }, + { name => 'colB', + ... + }, + { name => 'colC', + ... + }, + ], + 'PRIMARY KEY' => (index_col_name,...), + KEY => [{ name => 'idx_name', + columns => (col1,col2,..),},], + INDEX => [{ name => 'idx_name', + columns => (col1,col2,..),},], + UNIQUE => [{ index => 'yes', + name => 'idx_name', + columns => (col1,col2,..),},], + FULLTEXT => [{ index => 'yes', + name => 'idx_name', + columns => (col1,col2,..),},], + } -Returns: - undef on error, table id on success. +Returns: scalar string containing mysql commands to create the table =cut ############################### -sub create_table { - return undef if (!&connect_to_db($dbh)); +sub build_table_creation_request { my ($table_des)=@_; # # Build request to create table ################################## my @Columns; my $col_des; - my $tableid = &get_new_table_id(); - my $tablename = &translate_id($tableid); + my $table_id; + if (exists($table_des->{'id'})) { + $table_id = $table_des->{'id'}; + } else { + $table_id = &get_new_table_id(); + } + my $tablename = &translate_id($table_id); my $request = "CREATE TABLE IF NOT EXISTS ".$tablename." "; - foreach my $column (@{$table_des->{'column_order'}}) { + foreach my $coldata (@{$table_des->{'columns'}}) { + my $column = $coldata->{'name'}; + next if (! defined($column)); $col_des = ''; - my $coldata = $table_des->{'columns'}->{$column}; - if (lc($coldata->{'type'}) eq 'fulltext') { - $col_des.='FULLTEXT '.$column." (".$coldata->{'target'}.")"; - next; # Skip to the continue block and store the column data - } elsif (lc($coldata->{'type'}) =~ /(enum|set)/) { # 'enum' or 'set' + if (lc($coldata->{'type'}) =~ /(enum|set)/) { # 'enum' or 'set' $col_des.=$column." ".$coldata->{'type'}."('". join("', '",@{$coldata->{'values'}})."')"; } else { @@ -501,45 +724,60 @@ sub create_table { if (exists($coldata->{'default'})) { $col_des.=" DEFAULT '".$coldata->{'default'}."'"; } - $col_des.=' AUTO_INCREMENT' if (exists($coldata->{'auto_inc'})); - $col_des.=' PRIMARY KEY' if (exists($coldata->{'primary_key'})); + $col_des.=' AUTO_INCREMENT' if (exists($coldata->{'auto_inc'}) && + ($coldata->{'auto_inc'} eq 'yes')); + $col_des.=' PRIMARY KEY' if (exists($coldata->{'primary_key'}) && + ($coldata->{'primary_key'} eq 'yes')); } continue { # skip blank items. push (@Columns,$col_des) if ($col_des ne ''); } + if (exists($table_des->{'PRIMARY KEY'})) { + push (@Columns,'PRIMARY KEY ('.join(',',@{$table_des->{'PRIMARY KEY'}}) + .')'); + } + # + foreach my $indextype ('KEY','INDEX') { + next if (!exists($table_des->{$indextype})); + foreach my $indexdescription (@{$table_des->{$indextype}}) { + my $text = $indextype.' '; + if (exists($indexdescription->{'name'})) { + $text .=$indexdescription->{'name'}; + } + $text .= ' ('.join(',',@{$indexdescription->{'columns'}}).')'; + push (@Columns,$text); + } + } + # + foreach my $indextype ('UNIQUE','FULLTEXT') { + next if (! exists($table_des->{$indextype})); + foreach my $indexdescription (@{$table_des->{$indextype}}) { + my $text = $indextype.' '; + if (exists($indexdescription->{'index'}) && + $indexdescription->{'index'} eq 'yes') { + $text .= 'INDEX '; + } + if (exists($indexdescription->{'name'})) { + $text .=$indexdescription->{'name'}; + } + $text .= ' ('.join(',',@{$indexdescription->{'columns'}}).')'; + push (@Columns,$text); + } + } + # $request .= "(".join(", ",@Columns).") "; unless($table_des->{'permanent'} eq 'yes') { $request.="COMMENT = 'temporary' "; } $request .= "TYPE=MYISAM"; - # - # Execute the request to create the table - ############################################# - my $count = $dbh->do($request); - if (! defined($count)) { - $errorstring = "$dbh ATTEMPTED:\n".$request."\nRESULTING ERROR:\n". - return undef; - } - # - # Set up the internal bookkeeping - ############################################# - delete($Tables{$tablename}) if (exists($Tables{$tablename})); - my @column_order_copy = @{$table_des->{'column_order'}}; - $Tables{$tablename} = { - columns => $table_des->{'columns'}, - column_order => $table_des->{'column_order'}, - table_info => &get_table_info($tableid), - }; - $debugstring = "$dbh Created table $tablename at time ".time. - " with request\n$request"; - return $tableid; + return $request; } ############################### =pod -=item &get_new_table_id +=item &get_new_table_id() Used internally to prevent table name collisions. @@ -548,7 +786,6 @@ Used internally to prevent table name co ############################### sub get_new_table_id { my $newid = 0; - my $name_regex = '^'.$ENV{'user.name'}.'_'.$ENV{'user.domain'}."_(\d+)\$"; my @tables = &tables_in_db(); foreach (@tables) { if (/^$ENV{'user.name'}_$ENV{'user.domain'}_(\d+)$/) { @@ -562,23 +799,7 @@ sub get_new_table_id { =pod -=item &execute_db_command - -Currently unimplemented - -=cut - -############################### -sub execute_db_command { - my ($tablename,$command) = @_; - return 1; -} - -############################### - -=pod - -=item &get_rows +=item &get_rows() Inputs: $table_id,$condition @@ -593,8 +814,21 @@ greater than 0 being returned. ############################### sub get_rows { my ($table_id,$condition) = @_; + return undef if (! defined(&connect_to_db())); + my $table_status = &check_table($table_id); + return undef if (! defined($table_status)); + if (! $table_status) { + $errorstring = "table $table_id does not exist."; + return undef; + } my $tablename = &translate_id($table_id); - my $request = 'SELECT * FROM '.$tablename.' WHERE '.$condition; + my $request; + if (defined($condition) && $condition ne '') { + $request = 'SELECT * FROM '.$tablename.' WHERE '.$condition; + } else { + $request = 'SELECT * FROM '.$tablename; + $condition = 'no condition'; + } my $sth=$dbh->prepare($request); $sth->execute(); if ($sth->err) { @@ -605,11 +839,6 @@ sub get_rows { } $debugstring = "Got rows matching $condition"; my @Results = @{$sth->fetchall_arrayref}; - foreach my $row (@Results) { - for(my $i=0;$i<@$row;$i++) { - $row->[$i]=&Apache::lonnet::unescape($row->[$i]); - } - } return @Results; } @@ -617,7 +846,7 @@ sub get_rows { =pod -=item &store_row +=item &store_row() Inputs: table id, row data @@ -628,31 +857,38 @@ returns undef on error, 1 on success. ############################### sub store_row { my ($table_id,$rowdata) = @_; + # + return undef if (! defined(&connect_to_db())); + my $table_status = &check_table($table_id); + return undef if (! defined($table_status)); + if (! $table_status) { + $errorstring = "table $table_id does not exist."; + return undef; + } + # my $tablename = &translate_id($table_id); - my $table = $Tables{$tablename}; + # my $sth; - if (exists($table->{'row_insert_sth'})) { - $sth = $table->{'row_insert_sth'}; + if (exists($Tables{$tablename}->{'row_insert_sth'})) { + $sth = $Tables{$tablename}->{'row_insert_sth'}; } else { - # We need to build a statement handler + # Build the insert statement handler + return undef if (! defined(&update_table_info($table_id))); my $insert_request = 'INSERT INTO '.$tablename.' VALUES('; - foreach (@{$table->{'column_order'}}) { - # Skip the 'fulltext' columns. - next if (lc($table->{'columns'}->{$_}->{'type'}) eq 'fulltext'); + foreach (@{$Tables{$tablename}->{'Col_order'}}) { $insert_request.="?,"; } chop $insert_request; $insert_request.=")"; $sth=$dbh->prepare($insert_request); + $Tables{$tablename}->{'row_insert_sth'}=$sth; } my @Parameters; if (ref($rowdata) eq 'ARRAY') { @Parameters = @$rowdata; } elsif (ref($rowdata) eq 'HASH') { - foreach (@{$table->{'column_order'}}) { - # Is this appropriate? Am I being presumptious? ACK!!!!! - next if (lc($table->{'columns'}->{$_}->{'type'}) eq 'fulltext'); - push(@Parameters,&Apache::lonnet::escape($rowdata->{$_})); + foreach (@{$Tables{$tablename}->{'Col_order'}}) { + push(@Parameters,$rowdata->{$_}); } } $sth->execute(@Parameters); @@ -665,11 +901,124 @@ sub store_row { return 1; } + +############################### + +=pod + +=item &bulk_store_rows() + +Inputs: table id, [columns],[[row data1].[row data2],...] + +returns undef on error, 1 on success. + +=cut + +############################### +sub bulk_store_rows { + my ($table_id,$columns,$rows) = @_; + # + return undef if (! defined(&connect_to_db())); + my $dbh = &get_dbh(); + return undef if (! defined($dbh)); + my $table_status = &check_table($table_id); + return undef if (! defined($table_status)); + if (! $table_status) { + $errorstring = "table $table_id does not exist."; + return undef; + } + # + my $tablename = &translate_id($table_id); + # + my $request = 'INSERT IGNORE INTO '.$tablename.' '; + if (defined($columns) && ref($columns) eq 'ARRAY') { + $request .= join(',',@$columns).' '; + } + if (! defined($rows) || ref($rows) ne 'ARRAY') { + $errorstring = "no input rows given."; + return undef; + } + $request .= 'VALUES '; + foreach my $row (@$rows) { + # avoid doing row stuff here... + $request .= '('.join(',',@$row).'),'; + } + $request =~ s/,$//; + $dbh->do($request); + if ($dbh->err) { + $errorstring = 'Attempted '.$/.$request.$/.'Got error '.$dbh->errstr(); + return undef; + } + return 1; +} + + +############################### + +=pod + +=item &replace_row() + +Inputs: table id, row data + +returns undef on error, 1 on success. + +Acts like &store_row() but uses the 'REPLACE' command instead of 'INSERT'. + +=cut + +############################### +sub replace_row { + my ($table_id,$rowdata) = @_; + # + return undef if (! defined(&connect_to_db())); + my $table_status = &check_table($table_id); + return undef if (! defined($table_status)); + if (! $table_status) { + $errorstring = "table $table_id does not exist."; + return undef; + } + # + my $tablename = &translate_id($table_id); + # + my $sth; + if (exists($Tables{$tablename}->{'row_replace_sth'})) { + $sth = $Tables{$tablename}->{'row_replace_sth'}; + } else { + # Build the insert statement handler + return undef if (! defined(&update_table_info($table_id))); + my $replace_request = 'REPLACE INTO '.$tablename.' VALUES('; + foreach (@{$Tables{$tablename}->{'Col_order'}}) { + $replace_request.="?,"; + } + chop $replace_request; + $replace_request.=")"; + $sth=$dbh->prepare($replace_request); + $Tables{$tablename}->{'row_replace_sth'}=$sth; + } + my @Parameters; + if (ref($rowdata) eq 'ARRAY') { + @Parameters = @$rowdata; + } elsif (ref($rowdata) eq 'HASH') { + foreach (@{$Tables{$tablename}->{'Col_order'}}) { + push(@Parameters,$rowdata->{$_}); + } + } + $sth->execute(@Parameters); + if ($sth->err) { + $errorstring = "$dbh ATTEMPTED replace @Parameters RESULTING ERROR:\n". + $sth->errstr; + return undef; + } + $debugstring = "Stored row."; + return 1; +} + ########################################### =pod -=item tables_in_db +=item &tables_in_db() Returns a list containing the names of all the tables in the database. Returns undef on error. @@ -678,28 +1027,30 @@ Returns undef on error. ########################################### sub tables_in_db { - return undef if (! &connect_to_db()); # bail out if we cannot connect - my $sth=$dbh->prepare('SHOW TABLES;'); + return undef if (!defined(&connect_to_db())); + my $sth=$dbh->prepare('SHOW TABLES'); $sth->execute(); - if ($sth->err) { - $errorstring = "$dbh ATTEMPTED:\n".'SHOW TABLES'."\nRESULTING ERROR:\n". - $sth->errstr; + $sth->execute(); + my $aref = $sth->fetchall_arrayref; + if ($sth->err()) { + $errorstring = + "$dbh ATTEMPTED:\n".'fetchall_arrayref after SHOW TABLES'. + "\nRESULTING ERROR:\n".$sth->errstr; return undef; } - my $aref = $sth->fetchall_arrayref; - my @table_list=(); + my @table_list; foreach (@$aref) { - push @table_list,$_->[0]; + push(@table_list,$_->[0]); } - $debugstring = "Got list of tables in DB: @table_list"; - return @table_list; + $debugstring = "Got list of tables in DB: ".join(',',@table_list); + return(@table_list); } ########################################### =pod -=item &translate_id +=item &translate_id() Used internally to translate a numeric table id into a MySQL table name. If the input $id contains non-numeric characters it is assumed to have @@ -722,7 +1073,9 @@ sub translate_id { =pod -=item &check_table($id) +=item &check_table() + +Input: table id Checks to see if the requested table exists. Returns 0 (no), 1 (yes), or undef (error). @@ -732,12 +1085,13 @@ undef (error). ########################################### sub check_table { my $table_id = shift; + return undef if (!defined(&connect_to_db())); + # $table_id = &translate_id($table_id); - return undef if (! &connect_to_db()); my @Table_list = &tables_in_db(); my $result = 0; foreach (@Table_list) { - if (/^$table_id$/) { + if ($_ eq $table_id) { $result = 1; last; } @@ -748,7 +1102,106 @@ sub check_table { return $result; } +########################################### + +=pod + +=item &remove_from_table() + +Input: $table_id, $column, $value + +Returns: the number of rows deleted. undef on error. + +Executes a "delete from $tableid where $column like binary '$value'". + +=cut + +########################################### +sub remove_from_table { + my ($table_id,$column,$value) = @_; + return undef if (!defined(&connect_to_db())); + # + $table_id = &translate_id($table_id); + my $command = 'DELETE FROM '.$table_id.' WHERE '.$column. + " LIKE BINARY ".$dbh->quote($value); + my $sth = $dbh->prepare($command); + unless ($sth->execute()) { + $errorstring = "ERROR on execution of ".$command."\n".$sth->errstr; + return undef; + } + $debugstring = $command; + my $rows = $sth->rows; + return $rows; +} + +########################################### + +=pod + +=item drop_table($table_id) + +Issues a 'drop table if exists' command + +=cut + +########################################### + +sub drop_table { + my ($table_id) = @_; + return undef if (!defined(&connect_to_db())); + # + $table_id = &translate_id($table_id); + my $command = 'DROP TABLE IF EXISTS '.$table_id; + my $sth = $dbh->prepare($command); + $sth->execute(); + if ($sth->err) { + $errorstring = "ERROR on execution of ".$command."\n".$sth->errstr; + return undef; + } + $debugstring = $command; + delete($Tables{$table_id}); # remove any knowledge of the table + return 1; # if we got here there was no error, so return a 'true' value +} + + + + +# ---------------------------- convert 'time' format into a datetime sql format +sub sqltime { + my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = + localtime(&unsqltime($_[0])); + $mon++; $year+=1900; + return "$year-$mon-$mday $hour:$min:$sec"; +} + +sub maketime { + my %th=@_; + return POSIX::mktime(($th{'seconds'},$th{'minutes'},$th{'hours'}, + $th{'day'},$th{'month'}-1, + $th{'year'}-1900,0,0,$th{'dlsav'})); +} + + +######################################### +# +# Retro-fixing of un-backward-compatible time format + +sub unsqltime { + my $timestamp=shift; + if ($timestamp=~/^(\d+)\-(\d+)\-(\d+)\s+(\d+)\:(\d+)\:(\d+)$/) { + $timestamp=&maketime('year'=>$1,'month'=>$2,'day'=>$3, + 'hours'=>$4,'minutes'=>$5,'seconds'=>$6); + } + return $timestamp; +} + + 1; __END__; +=pod + +=back + +=cut