How do you set in MySQL the timestamp type column to be returned as integer by default?
To specify:
I know that I can query
select UNIX_TIMESTAMP(timestamp_column) from table ...,
but when I query
select * from table ...
How can I force timestamp_column to be returned as int, and not as YYYY-MM-DD HH:ii:ss, in every query like the previous one?
Is there a query like set names utf8 that I can execute to make the described behaviour default?
Related
I was trying to convert an existing varchar column with a unique index on it to a case sensitive column. So to do this, I updated the collation of the particular column.
Previous value: utf8mb4_unicode_ci
Current value: utf8mb4_bin
Now I have a row in my table TEST_TABLE with test_column value is abcd.
When I try to run a simple query like SELECT * FROM TEST_TABLE WHERE test_column = 'abcd'; it returns no result.
However when I try SELECT * FROM TEST_TABLE WHERE test_column LIKE 'abcd'; it returns the data correctly.
Also when I try SELECT * FROM TEST_TABLE WHERE BINARY test_column = 'abcd'; it returns the data correctly.
One more thing I tried was creating a duplicate of the table with column collation set as utf8mb4_bin while creating itself and then copy all data from original table. Then the query SELECT * FROM TEST_TABLE WHERE test_column = 'abcd'; is working alright.
So this seems to be a problem with BINARY conversion. Is there any solution to this or Am I doing something wrong ?
This seems to be an issue with MySQL. The steps I followed to resolve this is as follows:
dropped the unique index on the column
change the collation of the column
created the unique index again
Now it is working as expected. It seems MySQL didn't rebuild unique index when collation was changed. However the above steps solved my issue.
How did you change the collation? There are about 4 ways that you might think to do it. Most do something different.
Probably ALTER TABLE ... CONVERT TO COLLATION utf8mb4_bin was what you needed.
Why "bin"? You want to match case and accents? That is "abcd" != "Abcd"?
Currently, I have the MySQL 5.6 version. In this version INT type column will take 0 automatically even by default value is none.
Column = question_status, Type= INT, Default= None
Old query : INSERT INTO tbl_question (question_status) VALUES ('');
Above Query will Run Perfectly on my older version.
Now, I have imported the database into a newer version of MySQL 5.7.2
New query : INSERT INTO tbl_question (question_status) VALUES ('');
Above query is same but it says I have to change the default value of column because column datatype is INT.
if I'll change the default value manually to 0 in the newer version. It will run perfectly.
The problem is I have around 100 tables in a database and many INT Type columns so I cant change default value of every column one by one.
You can select all columns having an INT type with this query:
SELECT * FROM information_schema.columns WHERE table_schema = '<YOUR_DB>' data_type = 'INT'
Then it will be easy to write a simple script for a mass alter.
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
I'm attempting to insert a datetime('2013-08-30 19:05:00') value into a SQL server database table column(smalldatetime) and the value stays "NULL" after the insert.
I'm doing this to 6 other columns that are the exact same type. What is this only occuring on one column? I've triple checked that the names of the columns are correct. Any ideas?
Assuming the situation is as you describe
CREATE TABLE T
(
S SMALLDATETIME NULL
)
INSERT INTO T
VALUES('2013-08-30 19:05:00')
SELECT *
FROM T /*Returns NULL*/
There are only two ways I can think of that this can happen.
1) That is an ambiguous datetime format. Under the wrong session options this won't cast correctly and if you have some additional options OFF it will return NULL rather than raise an error (e.g.)
SET LANGUAGE Italian;
SET ansi_warnings OFF;
SET arithabort OFF;
INSERT INTO T
VALUES('2013-08-30 19:05:00')
SELECT *
FROM T /*NULL inserted*/
2) You may have missed the column out in an INSTEAD OF trigger, or have an AFTER trigger that actually sets the value back to NULL.
CREATE TABLE dummy (
id INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY ,
name VARCHAR( 30 ) NOT NULL
) ENGINE = MYISAM ;
and running this query:
SELECT GROUP_CONCAT(`name` SEPARATOR "||") FROM `dummy`
This query joins name column in all rows with || in a single column. BUT, the result is truncated with mysql configuration as explained in mysql manual :
"... result is truncated to the maximum length that is given by the group_concat_max_len system variable, which has a default value of 1024 ..."
Also in manual it is said that this setting can be changed in run time by the following syntax:
SET [GLOBAL | SESSION] group_concat_max_len = val;
Does changing this configuration works in all mysql server environments? If not, how can I achieve the same result without GROUP_CONCAT without limits?
Also, I think that changing the configuration will not solve my problem because I don't know what to set the value of group_concat_max_len because number of rows in dummy table can be any number.
Thanks.
Have you tried using stored procedure to accomplish your task? You can create a temporary table with a single row/column and append to it while fetching rows from your table. In the end just SELECT the single value from the temporary table.
You can find information about stored routines in mysql manual and other places.