I would like to copy a SQL's row into the same table.
But in my table, I've a 'text' column.
With this SQL:
CREATE TEMPORARY TABLE produit2 ENGINE=MEMORY SELECT * FROM produit WHERE pdt_ID = 'IPSUMS';
UPDATE produit2 SET pdt_ID='ID_TEMP';
INSERT INTO produit SELECT * FROM produit2;
DROP TABLE produit2;
I get this error :
#1163 - The used table type doesn't support BLOB/TEXT columns
Here is my table :
pdt_ID varchar(6)
pdt_nom varchar(130)
pdt_stitre varchar(255)
pdt_accroche varchar(255)
pdt_desc text
pdt_img varchar(25)
pdt_pdf varchar(10)
pdt_garantie varchar(80)
edit_ID varchar(7)
scat_ID int(11)
pdt_asso1 char(3)
pdt_asso2 char(3)
pdt_online tinyint(4)
It's possible to help me to duplicate row ? How?
You can't store TEXT-columns (which really are blobs) in memory tables. See here
Depending on your ultimate goal, you may insert a md5-hash of the TEXT-column instead to preserve entity identity. Otherwise you need to put pdt_desc and such into another table and refer to it's primary key - that will save you some storage/memory too.
Related
Here's what I'm trying to do:
CREATE TABLE IF NOT EXISTS hashes (
id int NOT NULL AUTO_INCREMENT,
text varchar(50) NOT NULL,
hash varchar(64) NOT NULL AS (SHA2(CONCAT(text), 256) STORED,
PRIMARY KEY (id)
) DEFAULT CHARSET=utf8;
And then I want to run an insert like this:
INSERT INTO `hashes` (`text`) VALUES ('testing');
From the research I've done, the id should be automatically generated since auto_increment is enabled, so I don't need to define it in the insert query.
From my CREATE TABLE query, the hash should be automatically generated based upon the data entered into the text field. However, when I run the CREATE TABLE command I get an error with this line:
hash varchar(64) NOT NULL AS (SHA2(CONCAT(text), 256) STORED
I'm just wanting the hash to be automatically generated similar to how CURRENT_TIMESTAMP will automatically generate the current time by default.
What am I doing wrong?
It seems you have syntax error. You should write NOT NULL after SHA2 hash function. Please try:
CREATE TABLE IF NOT EXISTS hashes (
id int NOT NULL AUTO_INCREMENT,
text varchar(50) NOT NULL,
hash varchar(64) AS (SHA2(CONCAT(text), 256)) STORED NOT NULL ,
PRIMARY KEY (id)
) DEFAULT CHARSET=utf8;
INSERT INTO `hashes` (`text`) VALUES ('testing');
You don't need to declare your hash column as NOT NULL. It's based on another NOT NULL column, text, so the hash will naturally be NOT NULL as well.
You also have forgotten a closing parenthesis.
hash varchar(64) AS (SHA2(CONCAT(text), 256) STORED,
1 2 3 3 2 ^
You need another closing paren where I indicated ^.
If you already have the table filled by some content, you can Alter it with :
ALTER TABLE `page` ADD COLUMN `hash` char(64) AS (SHA2(`content`, 256)) AFTER `content`
This solution will add hash column right after the content one, make hash for existing and new records too. Unique index can be added to prevent insertion of large content duplicates.
I have a MYSQL table, with 5 columns in it:
id bigint
name varchar
description varchar
slug
Can I get MySQL to automatically generate the value of slug as a 256 Bit Hash of name+description?
I am now using PHP to generate an SHA256 value of the slug prior to saving it.
Edit:
By automatic, I mean see if it's possible to change the default value of the slug field, to be a computed field that's the sha256 of name+description.
I already know how to create it as part of an insert operation.
MySQL 5.7 supports generated columns so you can define an expression, and it will be updated automatically for every row you insert or update.
CREATE TABLE IF NOT EXISTS MyTable (
id int NOT NULL AUTO_INCREMENT,
name varchar(50) NOT NULL,
description varchar(50) NOT NULL,
slug varchar(64) AS (SHA2(CONCAT(name, description), 256)) STORED NOT NULL,
PRIMARY KEY (id)
) DEFAULT CHARSET=utf8;
If you use an earlier version of MySQL, you could do this with TRIGGERs:
CREATE TRIGGER MySlugIns BEFORE INSERT ON MyTable
FOR EACH ROW SET slug = SHA2(CONCAT(name, description));
CREATE TRIGGER MySlugUpd BEFORE UPDATE ON MyTable
FOR EACH ROW SET slug = SHA2(CONCAT(name, description), 256);
Beware that concat returns NULL if any one column in the input is NULL. So, to hash in a null-safe way, use concat_ws. For example:
select md5(concat_ws('', col_1, .. , col_n));
Use MySQL's CONCAT() to combine the two values and SHA2() to generate a 256 bit hash.
CREATE TABLE IF NOT EXISTS `mytable` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(50) NOT NULL,
`description` varchar(50) NOT NULL,
`slug` varchar(64) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;
INSERT INTO `mytable` (`name`,`description`,`slug`)
VALUES ('Fred','A Person',SHA2(CONCAT(`name`,`description`),256));
SELECT * FROM `mytable`
OUTPUT:
COLUMN VALUE
id 1
name Fred
description A Person
slug ea76b5b09b0e004781b569f88fc8434fe25ae3ad17807904cfb975a3be71bd89
Try it on SQLfiddle.
Sorry if this is an easy question, I am coming to MySQL from SQL Server.
When I execute my create statement it contains nvarchar but commits to the database as varchar. Even in my alter statement afterwards the column does not change at all. Does the collation or DB engine make a difference?
During execution I am not encountering any issues in results, other than the fact the column changes datatype. I attached a screencast of my activity http://screencast.com/t/wc94oei2
I have not been able to find anyone with similar issues through my Google searches
Did you mean, this..
CREATE TABLE stars (
idstars int(11) NOT NULL AUTO_INCREMENT,
Name nvarchar(200) DEFAULT NULL,
PRIMARY KEY (idstars),
UNIQUE KEY Name_UNIQUE (Name)
)
----turns to---
CREATE TABLE stars (
idstars int(11) NOT NULL AUTO_INCREMENT,
Name varchar(200) DEFAULT NULL,
PRIMARY KEY (idstars),
UNIQUE KEY Name_UNIQUE (Name)
)
I using a MySQL server (5.5.27 - Community Server). I have a table with this definition:
CREATE TABLE IF NOT EXISTS tbl_messages (
`msg_id` VARCHAR(50) NOT NULL ,
`msg_text` VARCHAR(50) NULL ,
PRIMARY KEY (`msg_id`);
I write a trigger that, when I do an insert, the server sets the msg_id column with the current time including microseconds with this format "yyyymmddhhnnssuuuuuu". "u" is for microseconds.
I created a trigger:
create trigger tbl_messages_trigger
before insert on tbl_messages
for each row
BEGIN
SET NEW.msg_id = DATE_FORMAT(NOW(),'%Y%m%d%H%i%s%f');
END;$$
But the msg_id column only gets values like this: 20130302144818*000000*, with microseconds in zero. ¿Is it possible capture the microseconds?
TIA,
From the code provided I guess that you are trying to use microsecond to minimize probability of getting same msg_id for different rows.
Also, msg_id is the primary key, which should not present any object-specific data but only be unique. There is a good link about: http://en.wikipedia.org/wiki/Surrogate_key
The best way to deal with primary keys in MySql is AUTO_INCREMENT column attribute. If you need insert time for messages, you may provide column for it:
CREATE TABLE tbl_messages
(
`msg_id` bigint(20) NOT NULL AUTO_INCREMENT,
`msg_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
`msg_text` VARCHAR(50) NULL,
PRIMARY KEY (`msg_id`)
);
I am searching this for hours.
I just want to copy some fields from one table into an another table. In the destination table the fields i want to copy doesn't exsist.
It's like, copy and paste.
Ex. I have to tables
Table A Like
`id` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(255) DEFAULT NULL,
`active` int(11) DEFAULT '0'
Table B like
`date` timestamp NULL DEFAULT CURRENT_TIMESTAMP,
`alias` varchar(255) DEFAULT NULL,
`voters` int(11) DEFAULT NULL,
`level` int(11) NOT NULL DEFAULT '0',
`content` text
Ex. I want to copy 'content , level, voters' from Table B to Table A with the same structure and data.
I have in my mind like this, But HOW?
Alter Table A Add content (same SCHEMA as TABLE B.content)
Alter Table A Add level (same SCHEMA as TABLE B.level)
Alter Table A Add level (voters SCHEMA as TABLE B.voters)
INSERT INTO A (col1 , col2 , col3)
SELECT colB1, colB2,colB3
FROM B
they must be that same datatype and size
UPDATE
if table A does not contain data you can create it like this
CREATE TABLE A LIKE B;
Use LIKE to create an empty table based on the definition of another table, including any column attributes and indexes defined in the original table:
then make the insert statement above
if you want to keep the data in table A and add some columns from table B you can merge these two table inside new Table X then you delete table A and rename X
CREATE TABLE X
SELECT * from emp;
Note: if table A contains many record this will take too much time and is not a good solution
but your select statement will contains join , if there is a relationship between A and B tell me to write a more specific solution