I have a MySQL table CHINESE with DEFAULT CHARSET=latin1 and it has a column NAME with CHARACTER SET latin1. I have huge amount to data stored in this table. Around a million rows. And, I want to execute the following commands on my database:
ALTER DATABASE <DATABASE_NAME> DEFAULT CHARACTER SET utf8
ALTER TABLE CHINESE DEFAULT CHARACTER SET utf8
ALTER TABLE CHINESE MODIFY NAME VARCHAR(30) CHARACTER SET utf8
Considering the fact that I have huge amount of data stored in this database. Should I run these commands on my database? Will these commands lock the database in any way?
I am using Java to query and insert values in database. Will appending ?useUnicode=yes&characterEncoding=UTF-8 in URI string help me?
It will take a long time,
I think is it is the best that you export a .sql out and don't the trans-code there replace latin1 to utf8 , then import back in a temp table. Finally swap the name of they.
Related
I need to store some data in a MySQL table, but I got some problems with theese kind of characters: "ā" "æ" "ō" "ĕ" (and so on)
Till now I had theese data stored in a SQLlite database and it was great because all was good, but now I'm trying to export it in a MySQL DB, but the strange chars are stored not in the good way, even if I tried different char encode. (UTF-8, UTF-16, latin blah blah)
Does anyone know the correct way to do so?
thanks a lot!!
utf8 needs to be established in about 4 places.
The column(s) in the database -- Use SHOW CREATE TABLE to verify that they are explicitly set to utf8, or defaulted from the table definition. (It is not enough to change the database default.)
The connection between the client and the server. See SET NAMES utf8.
The bytes you have.
If you are displaying the text in a web page, check the <meta> tag.
Either you can switch to BLOB datatype, or if you insist on using TEXT/VARCHAR/CHAR then you need to change charset of your table and database as shown below.
CREATE DATABASE mydbname
CHARACTER SET utf8
COLLATE utf8_general_ci;
USE mydbname;
CREATE TABLE `mytable` (
`data` varchar(200) COLLATE utf8_unicode_ci NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
If you already have a database with utf8 charset and collation set to utf8_general_ci then you can simply alter your table as mentioned below:
ALTER TABLE `mytable` CHANGE `data` `data` VARCHAR(100)
CHARSET utf8 COLLATE utf8_general_ci DEFAULT '' NOT NULL;
I have a very big database with data stored on latin1 charsets.
On database with phpmyadmin if i use lines like this:
alter table TABLE_NAME modify FIELD_NAME blob;
alter database DATABASE_NAME charset=utf8;
alter table TABLE_NAME modify FIELD_NAME varchar(255) character set utf8;
All goes on. Text was converting.
But i have a lot of fields, tables. How to make it on all tables, fields? Is there a good convertation php script?
Also i uses on iconv, but no changes from latin1 to utf-8
create new database in utf8
restore your database structure
run "ALTER TABLE the_latin_one CONVERT TO CHARACTER SET utf8;" for all of your tables
create php script that create sql.txt like this
file_put_contents(PATH2."sql.txt","insert into ". $TABLE[0]. " values(". (rtrim($q_col,",") ).");\n",FILE_APPEND);
really you must create all tables insert query. using "show FULL tables where Table_type<>'VIEW'" and "set character set 'latin1'" query may help you for do this. if you have any problem write a comment for me ;)
in command line mysql -u xxx -p yourDB< sql.txt
i do this and solve my problem after 3 years :))
my host has just updated phpmyadmin to version 4.0.3. I don't know if it is related to the following problem.
I have a table 'users' which stores user data for the site and all data is now being stored as numbers. Where I had a username of 'rich' it is now '72696368' which is it's ascii code.
Any ideas why this might have happened? I have a lot of tables and have checked them all, it is only the users table that has been modified. It is not critical as I can still log in and accept new users etc but I would like to know why this is happening.
Thanks a lot
EDIT The collation is utf8_general_c
try adding this snippet to the script you are running in the line in which you create the schema
DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci
for example :
CREATE SCHEMA IF NOT EXISTS `my_schema` DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci;
When I started my website I set all the table columns to "utf8_general_ci" thinking this would make everything store in UTF8.
According to the mysql_client_encoding() function in PHP, I've been using the latin1 for my connection all along.
I understand this isn't a new problem. My question is how do I correctly update my database so that it utf8 and without affecting the data that exists in my tables?
There are a bunch of answers StackOverflow but a lot I find vague. A couple more helpful ones were:
Query all data and update as UTF8 https://stackoverflow.com/a/2335254/158126
Use a script built to convert tables https://stackoverflow.com/a/13400547/158126
In your experience, what have you done to fix this issue and retain all user data in the MySQL tables?
For your situation, I'd suggest trying to following for each bad column (connected over a utf8 connection):
// create a new column to store the latin1
alter table <table> add <column-latin1> <length> character set latin1;
// copy the utf8 data into the latin1 column without charset conversion
update <table> set <column-latin1> = binary <column-utf8>;
// verify the latin1 data looks OK
select <column-latin1> from <table>;
// copy the latin1 column into the utf8 column WITH charset conversion
update <table> set <column-utf8> = <column-latin1>;
// verify the new, properly encoded UTF8 data looks OK
select <column-latin1> from <table>;
// remove the temporary columns
alter <table> drop <column-latin1>;
And set your clients to use a UTF8 connection.
I have three MySQL tables and I'm inserting Gujarati content into them. When I insert two tables, they're inserted fine and are readable but in one table, it is showing junk characters/unreadable text. How can I fix this?
MySQL has per-table character set settings.
You can check which character set you are using for each table - see How do I see what character set a MySQL database / table / column is?.
If that is your problem, you might be able to covert the table in question, using:
ALTER TABLE mytable CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
Just you have to like ...
in Your Mysql DataBase Table..
Just Change 'Collation' of column Name.
To 'utf8mb4_general_ci'.
and you can store any Gujarati font in database