| MySQL | PostgreSQL |
|---|---|
| $db=DBI→connect(“dbi:mysql:database= … ) | $db=DBI→connect(“dbi:Pg:database= … ) |
| MySQL | PostgreSQL |
|---|---|
| SHOW FULL PROCESSLIST / SHOW PROCESSLIST | SELECT * FROM pg_stat_activity |
| # | – |
| … WHERE lastname=“smith” | … WHERE lower(lastname)='smith' |
| DESCRIBE tablename | \d tablename |
| DROP TABLE IF EXISTS | DROP TABLE IF EXISTS |
| SELECT … INTO OUTFILE '/var/tmp/outfile' | COPY ( SELECT … ) TO '/var/tmp/outfile' |
| SHOW DATABASES | \l |
| SHOW TABLES | \dt |
| MySQL | PostgreSQL | comments |
|---|---|---|
TINYINT SMALLINT MEDIUMINT BIGINT | SMALLINT SMALLINT INTEGER BIGINT | see [2]; integer size in PostgreSQL is 4 Bytes signed (-2147483648 – +2147483647) |
TINYINT UNSIGNED SMALLINT UNSIGNED MEDIUMINT UNSIGNED INT UNSIGNED BIGINT UNSIGNED | SMALLINT INTEGER INTEGER BIGINT NUMERIC(20) | SQL doesn't know UNSIGNED, all numbers are signed. |
ZEROFILL | No replacement. | |
DOUBLE | DOUBLE PRECISION | |
BOOLEAN | BOOLEAN | MySQL Booleans are an alias for TINYINT(1); PostgreSQL doesn't auto-convert numbers into booleans. |
DATE TIME DATETIME | DATE TIME TIMESTAMP | |
TIMESTAMP NOT NULL DEFAULT NOW() | TIMESTAMP NOT NULL DEFAULT NOW() | |
LONGTEXT MEDIUMTEXT BLOB | TEXT TEXT BYTEA | TEXT |
columnname INT AUTO_INCREMENT | columnname SERIAL equals to: CREATE SEQUENCE tablename_columnname_seq;
CREATE TABLE tablename (
columnname INT4 NOT NULL
DEFAULT nextval('tablename_columnname_seq')
);
| SERIAL = 1 – 2147483647BIGSERIAL = 1 – 9223372036854775807 SERIAL is in fact an entity named SEQUENCE. It exists independently on the rest of your table. If you want to cleanup your system after dropping a table, you also have to DROP SEQUENCE tablename_columnname_seq. More on that topic... |
field ENUM (val_1, val_2, ...) | field VARCHAR(255) NOT NULL, CHECK (field IN (val_1, val_2, ...)) OR CREATE TYPE mood AS ENUM ('sad','ok','happy');
CREATE TABLE person ( current_mood mood ...
| PostgreSQL doesn't have the ENUM types prior to 8.3, so you need to simulate it with contraints when using < 8.3. |
Ref.: http://en.wikibooks.org/wiki/Converting_MySQL_to_PostgreSQL
Borrar todas las tablas de una base de datos
MYSQL="mysql -h HOST -u USERNAME -pPASSWORD -D DB_NAME"
$MYSQL -BNe "show tables" | awk '{print "set foreign_key_checks=0; drop table `" $1 "`;"}' | $MYSQL
unset MYSQL
También podemos usar la sintaxys LIKE para borrar solo algunas tablas que concuerden con algún patrón, útil cuando tenemos un programa que genera muchas tablas con un timestamp añadido
show tables like 'ifvolume_1%'
[mysqld] datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock old_passwords=1 log_bin = /var/log/mysql/mysql-bin.log relay-log = /var/log/mysql/mysql-relay.log max_binlog_size = 100M expire_logs_days = 2 max_binlog_size = 100M log-bin binlog-do-db=proxyauth skip-slave-start server-id=1 replicate-do-db=base replicate-do-table=base.tabla master-host=10.1.1.1 master-user=root master-password=contraseña master-port=3306 [mysql.server] user=mysql basedir=/var/lib
[mysqld] datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock old_passwords=1 log_bin = /var/log/mysql/mysql-bin.log relay-log = /var/log/mysql/mysql-relay.log max_binlog_size = 100M expire_logs_days = 2 max_binlog_size = 100M log-bin binlog-do-db=proxyauth skip-slave-start server-id=2 replicate-do-db=base replicate-do-table=base.tabla master-host=10.1.1.2 master-user=root master-password=contraseña master-port=3306 [mysql.server] user=mysql basedir=/var/lib
skip-slave-start Es para tener que hacer el start slave; manualmente (por si las dudas).
Importacion :
LOAD DATA LOCAL INFILE 'usuarios.csv' INTO TABLE usuarios FIELDS TERMINATED BY ',' ENCLOSED BY '"' LINES TERMINATED BY '\n' (nombre, pass, usuario);
Exportacion :
SELECT * FROM usuarios ORDER BY DATE DESC INTO OUTFILE "usuarios.csv" FIELDS TERMINATED BY ',' ENCLOSED BY '"' LINES TERMINATED BY '\r\n';
mysql -u root -p cdr -B -e "select * from \`calldetails\` limit 2;" | sed 's/\t/","/g;s/^/"/;s/$/"/;s/\n//g'
Oracle xe must be the buggiest free counterpart of a commercial product ever released.Here's a list of issues and solutions encountered on Ubuntu 10.04 so far.Few config tips first.
Q: After installing and sourcing /usr/lib/oracle/xe/app/oracle/product/10.2.0/server/bin/oracle_env.sh I was getting /usr/lib/oracle/xe/app/oracle/product/10.2.0/server/bin/nls_lang.sh: 114: [[: not found each time starting a shell
A: Change the nls_lang.sh to use your shell (/bin/bash) instead of /bin/sh on top of the script.
Q: after installing oracle xe I cannot login to apex (oracle web admin) under sys or system. It won't accept my login/password. Keeps saying access denied although I'm sure the password is correct (the one used during /etc/init.d/oracle-xe configure)
A: Use a longer password! It won't complain but seems like it doesn't like short passwords. Use at least 8 chars.Q:After some time your oracle connected application runs into
ORA-12519, TNS:no appropriate service handler found
A: Run the following statement from sqlplus or web admin (you should have it accessible due to above tips)
ALTER SYSTEM SET PROCESSES=150 SCOPE=SPFILE;
Found here
Q: How to remove oracle user from ubuntu desktop login screen.
A: Change the oracle's UID to smth below 1000.
$ sudo usermod –gid 999 oracle
After that change the ownership of the files in /var/tmp/.
oracle$ sudo chown -R oracle:dba /var/tmp/.oracle/
or you won't be able to start the DB anymore :)
Q: Cannot open Oracle web interface, Page cannot be displayed. Used to work before, and the DB is working.
A: Might happen especially if you selected to start the DB manually rather than on each boot. The symptoms might be a bit different, the DB might be started or might be not. Some services just fail to start.
Try restart :
$ sudo /etc/init.d/oracle-xe restart or $ sudo /etc/init.d/oracle-xe force-reload
Fuente: http://ubuntu-answers.blogspot.com/2010/10/oracle-xe-issues.html