I am getting this error
javax.servlet.ServletException: com.mysql.jdbc.NotUpdatable: Result
Set not updatable.
I know this error is regarding the primary key but for all my tables I initially insert a primary key.So for this table also I have a primary key.I am posting part of my code.
Statement st=con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_UPDATABLE);
ResultSet rs=st.executeQuery("Select * from test3 order by rand() limit 5");
List arrlist = new ArrayList();
while(rs.next()){
String xa =rs.getString("display");
if(xa.equals("1")){
arrlist.add(rs.getString("question_text"));
}
rs.updateString("display", "0");
rs.updateRow();
Just tell me if something is going wrong in this code.please help.
This is my database
+----------------+---------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+----------------+---------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| index_question | varchar(45) | YES | | NULL | |
| question_no | varchar(10) | YES | | NULL | |
| question_text | varchar(1000) | YES | | NULL | |
| file_name | varchar(128) | YES | | NULL | |
| attachment | mediumblob | YES | | NULL | |
| display | varchar(10) | YES | | NULL | |
+----------------+---------------+------+-----+---------+----------------+
You have to update the row immediately after you have fetched it (FOR UPDATE and rs.updateRow(),
OR
you have to write an UPDATE tablename set = where statement to update a row at any time
The query can not use functions. Try removing the "rand()" from the SQL query string.
See the JDBC 2.1 API Specification, section 5.6 for more details.
Related
Apologies if this is a stupid question, but this is my first time using MySQL and I can't seem to get this to work:
I have this table:
+------------------------------+------------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+------------------------------+------------------+------+-----+---------+----------------+
| id | int(10) unsigned | NO | PRI | NULL | auto_increment |
| policy_name | varchar(255) | NO | UNI | | |
| virus_lover | char(1) | YES | | NULL | |
| spam_lover | char(1) | YES | | NULL | |
| unchecked_lover | char(1) | YES | | NULL | |
| banned_files_lover | char(1) | YES | | NULL | |
| bad_header_lover | char(1) | YES | | NULL | |
| bypass_virus_checks | char(1) | YES | | NULL | |
and I would like to change virus_lover to NO
I have tried using
update policy set Null='N' where Field='virus_lover';
But this gives me a syntax error response. I have checked online and everyone seems to be suggesting this exact same command that doesn't seem to work for me.
Any help would be greatly appreciated.
MySQL Ver 14.14 Distrib 5.7.25
The correct way to modify column attributes is with the ALTER TABLE command:
ALTER TABLE policy MODIFY virus_lover CHAR(1) NOT NULL
Demo on dbfiddle
Since NULL is a reserved keyword and it's being used as a column name in the table, it must be quoted with backticks or brackets:
update policy set `Null`='N' where Field='virus_lover';
or
update policy set [Null]='N' where Field='virus_lover';
Changing the column name to a non-reserved keyword instead of NULL would make things easier as well.
I have a doubt with the following query.
update src_woz_waardeklasse_2011 a use index(waardeklasse_main,woz_val)
inner join waardeklasse_average b use index (waardeklasse)
on b.waardeklasse_new = a.waardeklasse
set a.woz_value = b.average
where b.waardeklasse_new = a.waardeklasse;
I am trying to update a new column 'woz_val' in the 'src_woz_waardeklasse_2011' table using the 'average' values from the 'waardeklasse_average' table. I am joining using the 'waaderklasse' numbers in both the tables. But the 'src_woz_waardeklasse_2011' table is nearly 7 million records and the 'waardeklasee_average' table is 46 records. So the query is taking a really long time. 25 minutes and counting.
Is there a way to optimize it? I am sure it's taking a long time as I am trying to compare values between a large table and a small table. I have included the table structure of both the tables below.
src_woz_waardeklasse_2011
+----------------------+---------------------------+------+-----+---------+-
---------------+
| Field | Type | Null | Key | Default |
Extra |
+----------------------+---------------------------+------+-----+---------+-
---------------+
| id | int(11) unsigned | NO | PRI | NULL |
auto_increment |
| postcode | varchar(150) | YES | MUL | NULL |
|
| huisnummeraanduiding | varchar(150) | YES | | NULL |
|
| huisletter | varchar(150) | YES | | NULL |
|
soort_woonobject | varchar(150) | YES | | NULL |
|
| bouwjaar | varchar(150) | YES | | NULL |
|
| bouwjaarsklasse | varchar(150) | YES | | NULL |
|
| inhoud | varchar(150) | YES | | NULL |
|
| reg_oppervlak | varchar(150) | YES | | NULL |
|
| woz_value | int(15) unsigned zerofill | YES | UNI | NULL |
|
| reg_oppervlak_bn | varchar(150) | YES | | NULL |
|
| waardeklasse | int(10) | NO | PRI | NULL |
|
| waardepeildatum | varchar(150) | YES | | NULL |
|
| zipandnumber | varchar(150) | YES | | NULL |
|
+----------------------+---------------------------+------+-----+---------+-
---------------+
waardeklasse_average
+-------------------------+---------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------------------------+---------+------+-----+---------+-------+
| waardeklasse_average_id | int(11) | NO | | NULL | |
| waardeklasse_new | int(10) | NO | PRI | NULL | |
| lower | int(11) | NO | | NULL | |
| higher | int(11) | NO | | NULL | |
| average | int(11) | NO | PRI | NULL | |
+-------------------------+---------+------+-----+---------+-------+
update src_woz_waardeklasse_2011 a use index(waardeklasse_main,woz_val)
Left join waardeklasse_average b
on b.waardeklasse_new = a.waardeklasse
set a.woz_value = b.average
where b.waardeklasse_new = a.waardeklasse;
Use the above query - in this you can use the left join and where condition to speed up the query.
Also don't use the index for the second table which has 46 record this will affect the performance - if the table has less records then index will create more burden in this case full table scan without index is lot better. Also if you have a cluster index in the first table(7 million) remove them and run the query, because for each and every update you perform default table structure And page alignment will be updated in the clustered index. Hope this helps..!
First, you don't need the where clause. Second, remove the index hints:
update src_woz_waardeklasse_2011 ww inner join
waardeklasse_average wa
on wa.waardeklasse_new = ww.waardeklasse
set ww.woz_value = wb.average ;
Then, try an index on src_woz_waardeklasse_2011(waardeklasse). This should improve the execution plan.
You might also check that the 46 records in the second table actually correspond to 46 updates. If the join conditions are wrong, you could be updating all the records.
EDIT:
Indexes have nothing to do with your problem. Updating 7 million records takes a long time. You might consider creating the data you want in a temporary table and then truncating the original table and inserting the new rows into it. Otherwise, batch the updates a few rows at a time.
update src_woz_waardeklasse_2011 a use index(waardeklasse_main,woz_val)
inner join waardeklasse_average b use index (waardeklasse)
on b.waardeklasse_new = a.waardeklasse
set a.woz_value = b.average
Where condition is not needed. As you had already mention that condition in On clause.
Try above query.
Here's my table.
+-------------------+--------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------------------+--------------+------+-----+---------+----------------+
| ID | int(11) | NO | PRI | NULL | auto_increment |
| Postcode | varchar(255) | YES | | NULL | |
| Town | varchar(255) | YES | | NULL | |
| Region | varchar(255) | YES | | NULL | |
| Company Name | varchar(255) | YES | | NULL | |
| Fee | double | YES | | NULL | |
| Company Benefits | varchar(255) | YES | | NULL | |
| Date Updated | date | YES | | NULL | |
| Website | mediumtext | YES | | NULL | |
| Updated By | varchar(255) | YES | | NULL | |
| Notes | varchar(255) | YES | | NULL | |
| LNG | varchar(255) | YES | | NULL | |
| LAT | varchar(255) | YES | | NULL | |
+-------------------+--------------+------+-----+---------+----------------+
You can see we have an "Updated by" column.
How can I make it so that, when a user updates the row, the "Updated By" column automatically updates (or inserts if it's a new row they're adding) with the currently logged-in users name?
Many Thanks
You will have to explicitly make sure about that and whenever an UPDATE is happening then you need to update that column as well saying below. Best way to assure it, have your application logic fill in the column whenever an UPDATE to the record is happening from current logged-in user principle or claim
update tbl1
set ...,
Updated By = <logged in user name>
where Id = <some val>
You can use USER() or CURRENT_USER() in Update or Insert statements to achieve needed effect.
From my side - the only one secure way is to create stored procedures, providing inserts or updates to desired table.
Indeed, this problem was discussed here:
mysql Set default value of a column as the current logged in user
Something like this !
CREATE TRIGGER `updater`.`tableName_BEFORE_INSERT` BEFORE INSERT ON `tableName`
FOR EACH ROW
BEGIN
Set New.Updated_By = current_user();
END
I am posting this thread in order to have some advices regarding the performance of my SQL query.
I have actually 2 tables, one which called HGVS_SNP with about 44657169 rows and another on run table which has an average of 2000 rows.
When I try to update field Comment of my run table it takes lot's of time to perform the query. I was wondering if there is any method to increase my SQL query.
Structure of HGVS_SNP Table:
+-----------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-----------+-------------+------+-----+---------+-------+
| snp_id | int(11) | YES | MUL | NULL | |
| hgvs_name | text | YES | | NULL | |
| source | varchar(8) | NO | | NULL | |
| upd_time | varchar(32) | NO | | NULL | |
+-----------+-------------+------+-----+---------+-------+
My run table has the following structure:
+----------------------+--------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+----------------------+--------------+------+-----+---------+-------+
| ID | varchar(7) | YES | | NULL | |
| Reference | varchar(7) | YES | MUL | NULL | |
| HGVSvar2 | varchar(120) | YES | MUL | NULL | |
| Comment | varchar(120) | YES | | NULL | |
| Compute | varchar(20) | YES | | NULL | |
+----------------------+--------------+------+-----+---------+-------+
Here's my query:
UPDATE run
INNER JOIN SNP_HGVS
ON run.HGVSvar2=SNP_HGVS.hgvs_name
SET run.Comment=concat('rs',SNP_HGVS.snp_id) WHERE run.Compute not like 'tron'
I`m guessing since you JOIN a text column with a VARCHAR(120) column that you don`t really need a text column. Make it a VARCHAR so you can index it
ALTER TABLE `HGVS_SNP` modify hgvs_name VARCHAR(120);
ALTER TABLE `HGVS_SNP` ADD KEY idx_hgvs_name (hgvs_name);
This will take a while on large tables
Now your JOIN should be much faster,also add an index on compute column
ALTER TABLE `run` ADD KEY idx_compute (compute);
And the LIKE is unnecessary,change it to
WHERE run.Compute != 'tron'
I have following a structure of MySQL table:
+------------+----------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+------------+----------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| reg | int(11) | NO | | NULL | |
| descr | text | YES | | NULL | |
| created_at | datetime | YES | | NULL | |
| updated_at | datetime | YES | | NULL | |
+------------+----------+------+-----+---------+----------------+
And with this way I am saving data to my database:
#saving = Table.new(:reg => 1234, :descr => params[:descr]).save
And my problem is - I don't know how it is possible, but this query does not save the number to column "reg". I am getting this error
Mysql2::Error: Column 'reg' cannot be null: INSERT INTOname_of_table(updated_at,descr,reg,created_at) VALUES ('2011-06-06 20:40:43', 'description of man', NULL, '2011-06-06 20:40:43')
I worked a lot with PHP and MySQL database, but this error I never got...
Where's the problem?
if you look at your schema, it says the default for :reg is NULL, and that it can not be NULL -- that might cause the problem you see
can you change the schema to allow :reg to be NULL and try again?