I want to insert some data into RDBMS(MYSQL5.7, JDBC5.1), and I am using executeBatch to speed up. I found that when one insert sql of a batch of statement cannot execute properly, the remain will be ignored. I have to say that not what I expectd. I want to let RDBMS just ignore my error sql and continue execution.
Can anyone tell me what should I do or show me the right documentation url.
And I am glad for your help!
And I know that "INSERT ... ON DUPLICATE KEY ... " can help ignore DUPLICATE KEY error , but I want one more general solution.
MySQL JDBC DOC
Connection connection = getConn();
Statement statemenet = connection.createStatement();
for (SearchUserItem user: result.getItems()) {
String query = "INSERT INTO TABLE VALUES(SOME_VALUES)";
}
int[] re = statemenet.executeBatch();
ananlyseBatchResult(re);
statemenet.close();
connection.close();
Related
So, I'm trying to insert data to a database completely dynamically, meaning the data will be inserted without any knowledge of what table we're inserting into. The same goes for the different attributes.
My problem is that for some reason, my table names get wrapped in '' when preparing the statment. It goes as follows:
String query = "INSERT INTO ? VALUES(?)";
try{
Connection conn = Connection.create();
PreparedStatment st = conn.prepareStatement(query);
st.setString(1, "test");
st.setString(2, "1");
st.addBatch();
//... (executes batch later on...)
catch (Exception e){
e.printStackTrace();
}
finally{
DbUtils.closeQuietly(rs);
DbUtils.closeQuietly(conn);
}
Now for some reason, and completely beyond me, if I print this statement I get:
"INSERT INTO 'test' VALUES("1");
while I would expect
"INSERT INTO test VALUES("1");
Could anyone explain why this happens and how I can solve this, or a better way to achieve what I'm trying to do? If it matters I'm using DbUtils to handle closing, and 3CP0 for connection pooling.
I have been looking all over without any luck. And I would also appreciate it if anyone could tell me if inserting data dynamically to different tables generally is a bad thing.
I have to execute multiple insert queries using JDBC for which I am trying to execute batch statement. Everything works fine in my code but when i try to see values in the table, the table is empty.
Here is the code :
SessionImpl sessionImpl = (SessionImpl) getSessionFactory().openSession();
Connection conn = (Connection) sessionImpl.connection();
Statement statement = (Statement) conn.createStatement();
for (String query : queries) {
statement.addBatch(query);
}
statement.executeBatch();
statement.close();
conn.close();
And the
List<String> queries
contains insert queries like:
insert into demo values (null,'Sharmzad','10006','http://demo.com','3 Results','some values','$44.00','10006P2','No Ratings','No Reviews','Egypt','Duration: 8 hours','tour','Day Cruises');
And the table structure is like:
create table demo ( ID INTEGER PRIMARY KEY AUTO_INCREMENT,supplierName varchar(200),supplierId varchar(200),supplierUrl varchar(200),totalActivities varchar(200),activityName varchar(200),activityPrice varchar(200),tourCode varchar(200),starRating varchar(200),totalReviews varchar(200),geography varchar(200),duration varchar(200),category varchar(200),subCategory varchar(200));
No exception is thrown anywhere but no value is inserted. Can someone explain?
Most JDBC drivers use autocommit, but some of them do not. If you don't know, you should use either .setAutoCommit(true) before the transaction or .commit() after it..
Could be a transaction issue. Perhaps you're not committing your transaction? If so, then it is normal not to see anything in the database.
You can check if this is the case by running a client in READ_UNCOMMITTED transaction mode, right after .executeBatch(); (but before close()) and see if there are any rows.
You don't should assign a value to ID add supply all the others columns name
insert into demo
(
supplierName
,supplierId
,supplierUrl
,totalActivities
,activityName
,activityPrice
,tourCode
,starRating
,totalReviews
,geography
,duration
,category
,subCategory
)
values (
'Sharmzad'
,'10006'
,'http://demo.com'
,'3 Results'
,'some values'
,'$44.00'
,'10006P2'
,'No Ratings'
,'No Reviews'
,'Egypt'
,'Duration: 8 hours
','tour'
,'Day Cruises'
);
and add commit to your code
I have a java servlet application and I'm using a prepared query to update a record in a SQL Server Database table.
Lets say I want to execute UPDATE MyTable SET name = 'test' WHERE id = '10'. (Yes, id is a varchar)
I used the following code to make this happen:
PreparedStatement pstmt = con.prepareStatement("UPDATE MyTable SET name = ? WHERE id = ?");
pstmt.setString(1, getName() );
pstmt.setString(2, getID() );
pstmt.executeUpdate();
I found out that while I was running a JMeter script to simulate 2 users, this statement causes a deadlock in my database.
I wanted to check what my values were in the SQL Profiler so I used the following code, so I could check the values.
String query = String.format("UPDATE MyTable SET name = '%s' WHERE id = '%s' ", getName(), getID() );
PreparedStatement pstmt = con.prepareStatement(query);
pstmt.executeUpdate();
Suddenly my deadlock was gone! It's a shame the last approach is vulnerable to SQL injection.
Is there somebody who can tell me what is going on and/or how to fix it?
Ok I finally found the problem and solution to my problem.
It seemed that the combination of the jTDS JDBC driver with MSSQL was the 'problem'.
This article explained my situation exactly. And with the help of this FAQ I was able to set the datasource to the right configuration.
From what I understand:
If you have statement that uses a String-like index (Like in my situation), the table performs an index SCAN instead of an index SEEK. This causes the whole table to be locked and vulnerable to deadlocks.
I hope this will help other people too.
I have a wierd behavior in a Java application.
It issues simple queries and modifications to a remote MySQL database. I found that queries, run by executeQuery() work just fine, but inserts or delete to the database run through executeUpdate() will fail.
Ruling out the first thing that comes to mind: the user the app connects with has correct privilledges set up, as the same INSERT run from the same machine, but in DBeaver, will produce the desired modification.
Some code:
Connection creation
Class.forName("com.mysql.jdbc.Driver");
connection = DriverManager.getConnection(url, user, pass);
Problematic part:
Statement parentIdStatement = connection.createStatement();
String parentQuery = String.format(ProcessDAO.GET_PARENT_ID, parentName);
if (DEBUG_SQL) {
plugin.getLogger().log(Level.INFO, parentQuery);
}
ResultSet result = parentIdStatement.executeQuery(parentQuery);
result.first();
parentId = result.getInt(1);
if (DEBUG_SQL) {
plugin.getLogger().log(Level.INFO, parentId.toString()); // works, expected value
}
Statement createContainerStatement = connection.createStatement();
String containerQuery = String.format(ContainerDAO.CREATE_CONTAINER, parentId, myName);
if (DEBUG_SQL) {
plugin.getLogger().log(Level.INFO, containerQuery); // works when issued through DBeaver
}
createContainerStatement.executeUpdate(containerQuery); // does nothing
"DAOs":
ProcessDAO.GET_PARENT_ID = "SELECT id FROM mon_process WHERE proc_name = '%1$s'";
ContainerDAO.CREATE_CONTAINER = "INSERT INTO mon_container (cont_name, proc_id, cont_expiry, cont_size) VALUES ('%2$s', %1$d, CURRENT_TIMESTAMP(), NULL)";
I suspect this might have to do with my usage of Statement and Connection.
This being a lightweight lightly-used app, I went to simplicity, so no framework, and no specific isntructions regarding transactions or commits.
So, in the end, this code was just fine. It worked today.
To answer the question: where to look first in a similar case (SELECT works but UPDATE / INSERT / DELETE does not)
If rights are not the problem, then there is probably a lock on the table you try to modify. In my case, someone left with an uncommited transaction open.
Proper SQL exceptions logging (which was suboptimal in my case) will help you figure it out.
I want to INSERT several rows using a PreparedStatement:
ps = con.prepareStatement(query,PreparedStatement.RETURN_GENERATED_KEYS);
for(Element e:listOfElements){
ps.setString(1,this.col_val_1);
ps.setString(2,this.col_val_2);
ps.setInt(3,this.col_val_3);
ps.addBatch();
}
ps.executeBatch();
ResultSet rs = ps.getGeneratedKeys();
At this point, whent I expect to get the PK's generated for each INSERT, I get this SQLServerException:
com.microsoft.sqlserver.jdbc.SQLServerException: The statement must be executed before any results can be obtained.
I expected to get a ResultSet with one row for each insert performed, so I could get each PK generated.
Am I expecting wrong? Am I doing something wrong? Can it be done in a different way using batch execution?
Support for getGeneratedKeys() on batch execution is implementation defined according to the JDBC spec. Most likely the SQL Server driver does not support it for batch execution.
I tried to look for an explicit statement on the Microsoft site, but couldn't find it. This old (2007) forum post on MSDN does state that it isn't supported: http://social.msdn.microsoft.com/Forums/en-US/sqldataaccess/thread/6cbf5eea-e5b9-4519-8e86-f4b65ce3f8e1