I have some problem in MYSQL syntax
This statement is work correctly
CONVERT(_latin1 'SOME-AR-TEXT' USING utf8));
But i don't need the 'SOME-AR-TEXT' value, i need the value of some variable.
In other words, i tried to do this
CONVERT(_latin1 (SELECT some_variable) USING utf8));
But the console display syntax error.
What can i do to get the value of some_variable variable.
Thank you all
SELECT CONVERT(some_variable USING UTF8) AS field_value
FROM MyTable
By your SQL fiddle it seems like you want to convert each field. Why not just create the table with default charset latin? In that way, you would not have to specifially convert each field.
CREATE TABLE IF NOT EXISTS `example` (
`some_variable` varchar(30) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
And there is something wrong the terminology as well. 'some_variable" isn't really a variable but a column/field in the database-table example.
Related
I have an existing table that holds valid JSON data but is stored as LONGTEXT (character set utf8mb4 with collation utf8mb4_bin). Doing JSON queries on this is highly inefficient and I want to change the data type of this column to JSON.
When I do so in HeidiSQL I get an: 'COLLATION 'utf8mb4_bin' is not valid for CHARACTER SET 'binary'. I can fix this by resetting the collation to empty.
I mention this because I thought the character set for a JSON column is utf8mb4 and it's default collation is utf8mb4_bin. In the JSON are some GUIDs and when I try to query them, it appears that I have to use LIKE. If I use the 'normal' = I get no results.
Works: SELECT * FROM MyTable WHERE Data->>"$.Shop[*].ContactPerson.UserId" LIKE "%b1b9ad95-1098-4e6c-a697-50c2a47dc301%";
Doesn't work: SELECT * FROM MyTable WHERE Data->>"$.Shop[*].ContactPerson.UserId" = "b1b9ad95-1098-4e6c-a697-50c2a47dc301";
Is that a problem with my syntax or is it related to collation (I'd say no, but it's the only discrepancy I find). BTW: Leaving out the % in the LIKE also produces no results.
Create/insert:
CREATE TABLE Temp ( `Data` LONGTEXT COLLATE UTF8MB4_BIN );
INSERT INTO Temp( `Data` ) VALUES ("{\"Shop\":[{\"ContactPerson\": {\"UserId\":\"b1b9ad95-1098-4e6c-a697-50c2a47dc301\"}},{\"ContactPerson\": {\"UserId\":\"B27DA5A7-D678-4513-8A44-BD76CC4651CC\"}}]}");
INSERT INTO Temp( `Data` ) VALUES ("{\"Shop\":[{\"ContactPerson\": {\"UserId\":\"82899A81-2024-4F68-917A-710764296A21\"}},{\"ContactPerson\": {\"UserId\":\"AE59DCA7-32AF-4131-93C7-A1BB698DF8E0\"}}]}");
INSERT INTO Temp( `Data` ) VALUES ("{\"Shop\":[{\"ContactPerson\": {\"UserId\":\"4154477B-1B70-4F25-9E4B-2CFBBF4F678F\"}},{\"ContactPerson\": {\"UserId\":\"B27DA5A7-D678-4513-8A44-BD76CC4651CC\"}}]}");
Trying the update: ALTER TABLE `Temp` MODIFY `Data` JSON;
And now it works... (of course) :(
So apparently when using the table-editor in HeidiSQL it fails (I've retried this). Using a SQL statement actually does what I want.
That still leaves me with having to use the LIKE as opposed to = in my query.
Thank you to #Rick James for the "aha moment": Where clause for JSON field on array of objects
So in my case:
SELECT * FROM `Temp` WHERE JSON_SEARCH(`Data`, 'one', 'b1b9ad95-1098-4e6c-a697-50c2a47dc301', NULL, '$.Shop[*].ContactPerson.UserId') IS NOT NULL;
Update:
Issue was reported and will be fixed in next build (https://github.com/HeidiSQL/HeidiSQL/issues/1652)
I'm using MySQL 8.0.4 (rc4) I need MySQL 8 because it's the only version of MySQL that supports CTEs.
My database is created thus:
CREATE DATABASE IF NOT EXISTS TestDB
DEFAULT CHARACTER SET utf8mb4
DEFAULT COLLATE utf8mb4_general_ci;
USE TestDB;
SET sql_mode = 'STRICT_TRANS_TABLES';
CREATE TABLE IF NOT EXISTS MyTable (
(...)
Body LONGBLOB NOT NULL,
(...)
);
When I try to insert raw byte data to this description field, I receive this error:
Error 1366: Incorrect string value: '\x8B\x08\x00\x00\x00\x00...' for column 'Body' at row 1.
This is the insert statement I'm using.
REPLACE INTO MyTable
SELECT Candidate.* FROM
(SELECT :Id AS Id,
(...)
:Body AS Body,
(...)
) AS Candidate
LEFT JOIN MyTable ON Candidate.Id = MyTable.Id
WHERE (
(...)
);
How could there be an incorrect string value for BLOB? Doesn't BLOB mean I can insert quite literally anything?
What's the : stuff? Why have the nested query? May we see actual SQL? What language are you using? It sounds like the "binding" tried to apply character set rules, when it should not. May we see the code that did the substitution of the : stuff?
BLOBs have not character set. As long as you can get the bytes past the parser, there should be no problem.
However, I find this to be a better way to do it...
In the app language, generate a hex string, then use that in
INSERT INTO ... VALUES (..., UNHEX(the-hex-string), ...)
I have a table ABC that has many columns, two of which are:
ID - VARCHAR(10) and ROLE VARCHAR(10).
Now I have been trying to update the column ROLE using the ID and this is the query:
UPDATE TABLE ABC
SET ROLE='READ_ONLY'
WHERE ID='AB234PQR'
Now for some unknown reason, i have been getting the error - truncated incorrect integer value. I have no idea where I am going wrong.I have been banging my head over this for a while now.
I have visited other questions with the similar title.All use convert or some other function in where clause, But I have not used any such thing, still it gives me the same error.
I checked the table description and it seems fine. Where can I be going wrong? Any help is appreciated.
Can you please try this:
UPDATE ABC
SET ROLE='READ_ONLY'
WHERE ID='AB234PQR'
The correct syntax to update table entries is:
UPDATE `table_name`
SET `column_name` = 'value'
WHERE `column_name2` = 'value2';
It is as well recommended to use backticks around table names and column names, just like the way you can see in my snippet above.
Therefore using
UPDATE `ABC`
SET `ROLE` = 'READ_ONLY'
WHERE `ID` = 'AB234PQR'
should do the trick.
I need to change the default value of sql table fields from 'none' to 'null' where the datatypes are char varchar longtext etc. And I want to keep the default value if its not 'none'. And there are more than 500 tables I need to alter. Is there any way to do so? And should I use PL? Is there any other methods to do so?Thanks in advance.
I assume you want to update the none to NULL and the column is of type varchar
update table_name set column = null where column = 'none';
you need to update schema of table as well, need to set the default value as NULL using alteration.
The code is:
ALTER TABLE 'tablename' ALTER COLUMN 'columnname' SET DEFAULT 'none'
First I selected all tables from database using this query:
$result = mysql_query("SHOW TABLES FROM 'database'";
And selected all columns using a loop:
mysql_fetch_field
Then I run the code: And it worked .Thank you every one who tried to help me.
I am working in a PHP + MySQL application. The application is working fine for me. But when I hosted it in another server, I got a MySQL error:
Error Code: 1364. Field 'field' doesn't have a default value
I know this is a problem with the MySQL version and we should setup default values for all columns. But currently I have more than 100 tables. So I need to set default value to NULL for all columns in all tables that has no default value yet.
I can't make use of the strict mode option, because the server is a shared one. Is it possible to setup in a single step rather than setting for each and every table ? If not possible tell me the easiest way to setup it.
Any help would be greatly appreciated
For anyone else with this problem, it will take a bit of coding to perform automatically, but the following would be how you would do so:
First run the following query:
SELECT table_schema,table_name,column_name,data_type FROM information_schema.columns WHERE IS_NULLABLE='NO' AND column_default is null AND column_key=''
Next, for each row returned from the above query perform the following:
If data_type contains 'int' set default to 0
else if data_type='datetime' set default to '0000-00-00 00:00:00'
else if data_type='date' set default to '0000-00-00'
else if data_type='time' set default to '00:00:00'
else set default to ''
create and run the following query with all [[...]] variables replaced with their proper values:
ALTER TABLE `[[table_schema]]`.`[[table_name]]` ALTER COLUMN `[[column_name]]` SET DEFAULT '[[default]]'
This should replace the default values for all databases, all tables, all columns that are set to be NOT NULL and are not primary keys and have no default value set.
Another solution that i found is like:-
Get all column name put it in array...
Now push values in column array for inserting -- with ZERO value for all those arrays we do not have values.
FOR EXAMPLE:
in a table we have COLUMN
NAME LASTNAME COMPNAME PHONO EMAIL ADDRESS ALTERPERSON ALTERPHONE ALTEREMAIL
Now after migration we see the eeror
Error Code: 1364. Field 'field' doesn't have a default value
if we run a INSERT QUERY LIKE
mysqli_query($con,'insert into table
(NAME,LASTNAME,COMPNAME,PHONO,EMAIL,ADDRESS) values
(NAME,LASTNAME,COMPNAME,PHONO,EMAIL,ADDRESS)')
now it will give error...
So just turn the table
get all the column value from DB.TABLE
put it in an array or do it like one by one using while loop or for loop....
check insert values for each column
put condition if insert value is equal to ZERO or NULL then insert ZERO it will solve all issues.
WHY ZERO --
because it will work for VARCHAR,TEXT,INT,BIGINT and in many Data Types except time or date function and DATE/TIME data type got ZERO values by default...
=============================== Another option...
run a PHP code
get all TABLE NAME
then for each TABLE NAME
get all COLUMN NAME
and run this command as in function under loop
ALTER TABLE DB.TABLEnAME CHANGE columnNAME_A columnNAME_A
VARCHAR(100) CHARACTER SET latin1 COLLATE latin1_swedish_ci NULL
DEFAULT NULL;
=======================
And its DONE