| Java JDBC | Perl DBI | MySQL/PHP | MySQL/C | Postgres/C | Postgres/PHP | |
| Open a connection | Class.forName(driver_name);
Connectioncon = DriverManger.getConnection(String url, Properties info); |
use
DBI;
$dbh = DBI->connect($dsn, $user, $password, { %attr }); |
$link = mysql_connect(
[server [, username [, password [, new_link [, client_flags]]]]]);
mysql_select_db(database_name [,link]) |
MYSQL *mysql_real_connect(MYSQL
*mysql, const char *host, const char *user, const char *passwd, const char
*db, unsigned int port, const char *unix_socket, unsigned long client_flag)
;
int mysql_select_db(MYSQL *mysql, const char *db) |
PGconn *PQconnectdb(const char *conninfo);
size_t ; |
$connection = pg_connect(connection_string);
OR $connection = pg_pconnect(connection_string); |
| Execute a non-SELECT query | Statement s = con.createStatement();
s.executeUpdate(String sql); |
$nrows = $dbh->do($statement, \%attr, @bind_values) | $result = mysql_query(query,
[link]);
$nrows = mysql_affected_rows([link]); |
unsigned long mysql_real_escape_string(MYSQL
*mysql, char *to, const char *from, unsigned long length) ;
int mysql_query(MYSQL *mysql, const char *query) |
PQescapeString (char *to, const char *from, size_t length);
PGresult *PQexec(PGconn *conn, const char *query); |
$result = pg_query(connection,
query);
$nrows = pg_affected_rows(result); |
| Execute a SELECT query | Statement s = con.createStatement();
ResultSet r = s.executeQuery(String sql); OR ps.setXxx(int, Xxx x); // repeat... ResultSet r = ps.executeQuery(); |
$ary_ref = $dbh->selectall_arrayref($statement,
\%attr, @bind_values);
OR $rv = $sth->execute(@bind_values) |
$result = mysql_query(query,
[link]);
|
mysql_query | $result = pg_query(connection, query); | |
| Prepare a SELECT query | PreparedStatement ps = con.prepareStatement(String sql); | $sth = $dbh->prepare($statement) | not supported | (none before v4.1) | not supported | |
| Read a row of results | rs.next(); | $ary_ref = $sth->fetchrow_arrayref
OR @ary = $sth->fetchrow_array; OR $hash_ref = $sth->fetchrow_hashref; OR $tbl_ary_ref = $sth->fetchall_arrayref; |
$row = mysql_fetch_array(result); | MYSQL_ROW mysql_fetch_row(MYSQL_RES *result) | $row = pg_fetch_array) | |
| Value of one column in the row of results | rs.getXxx(int);
OR rs.getXxx(String); |
$row[column]
OR $hash{column_name} |
$row[column]
OR $row[column_name] |
MYSQL_ROW is equivalent to:
typedef char *MYSQL_ROW[] |
$row[column]
OR $row[column_name] |
|
| Cleanup | not normally needed | not normally needed | not normally needed | void mysql_free_result(MYSQL_RES
*result) ;
void mysql_close(MYSQL *mysql) |
not normally needed |
Here's another random idea: I want to see a threaded mailreader that lets me dynamically edit the threads. I've used Opera, Kmail, Mozilla, Pine and Mutt, and none of them is 100% accurate at identifying threads. Part of this is the fault of the people who compose messages to mailing-lists and newsgroups: some people misdirect a reply, or use software that doesn't include a References: header, thus breaking the flow of the thread; other people reply to a message with a new, completely unrelated question just because they're too lazy to type the list's address into their mailer. I wish that I, as someone reading a set of messages, could fix broken or misapplied thread associations when I see them.
See also a comparison of collection classes.