currently I setting up a test environment for an application. I'm using jUnit and Spring in my test environment. Before a test execution I want to set up a database test environment state. I already has written the SQL scripts (schema and data) and they runs fine in Oracles SQLDeveloper. As I tried to execute them by using the oracle thin jdbc driver, the execution fails. It looks like that the thin driver doesn't like create trigger statements.
I read that I have to use an oci driver instead of thin driver. The problem with the oci driver is that it is not platform independent and it takes time to set it up.
Example of my code:
CREATE TABLE "USER"
(
USER_ID NUMBER(10) NOT NULL,
CREATOR_USER_FK NUMBER(10) NOT NULL,
...
PRIMARY KEY (USER_ID)
);
CREATE SEQUENCE SEQ_USER START WITH 1 INCREMENT BY 1;
CREATE TRIGGER "USER_ID_SEQ_INC" BEFORE
INSERT ON "USER" FOR EACH ROW BEGIN
SELECT SEQ_USER.nextval
INTO :new.USER_ID
FROM DUAL;
END;
If I execute the the trigger statement the execution fails, but I looks like that the first part of the query (CREATE TRIGGER "USER_ID_SEQ_INC" ... "USER" ... BEGIN ... FROM DUAL;) is executed successfully, but the trigger seems to be corrupt if I try to use it. The execution fail error comes with the second part of the statement END; "ORA-00900: invalid SQL statement".
Do anyone know a solution for that problem? I just want to create a trigger with platform independent thin jdbc driver.
Cheers!
Kevin
Thank you guys for your answers, It works fine now. The reason was a syntax mistake or the interpretation of my SQL code file with Spring Framefork. When I execute the statements directly by using the execute method of jdbc it works, when I use the Spring functionality for script execution the execution fails. With oracle sql code it seems to be tricky, because if I use hsqldb sql code it works fine.
test-condext.xml:
...
<jdbc:initialize-database data-source="dataSource"
ignore-failures="DROPS" enabled="${jdbc.enableSqlScripts}">
<jdbc:script location="${jdbc.initLocation}" />
<jdbc:script location="${jdbc.dataLocation}" />
</jdbc:initialize-database>
...
schema.sql:
DROP SEQUENCE SEQ_USER;
DROP TABLE "USER" CASCADE CONSTRAINTS;
PURGE TABLE "USER";
CREATE TABLE "USER"
(
USER_ID NUMBER(10) NOT NULL,
CREATOR_USER_FK NUMBER(10) NOT NULL,
PRIMARY KEY (USER_ID)
);
ALTER TABLE "USER" ADD CONSTRAINT FK_USER_CUSER FOREIGN KEY (CREATOR_USER_FK) REFERENCES "USER" (USER_ID);
CREATE SEQUENCE SEQ_USER START WITH 1 INCREMENT BY 1;
CREATE TRIGGER "USER_ID_SEQ_INC" BEFORE
INSERT ON "USER" FOR EACH ROW
WHEN (new.USER_ID IS NULL)
BEGIN
SELECT SEQ_USER.nextval
INTO :new.USER_ID
FROM DUAL;
END;
/
ALTER TRIGGER "USER_ID_SEQ_INC" ENABLE;
This works fine! Its important to remove ; at the end of statements excepts the trigger statement!!!
#Before
public void executeSomeSql() {
Connection c;
try {
c = dataSource.getConnection();
c.createStatement()
.execute("CREATE TABLE \"USER\" (USER_ID NUMBER(10) NOT NULL, CREATOR_USER_FK NUMBER(10) NOT NULL, PRIMARY KEY (USER_ID))");
c.createStatement()
.execute("CREATE SEQUENCE SEQ_USER START WITH 1 INCREMENT BY 1");
c.createStatement()
.execute("CREATE OR REPLACE TRIGGER \"USER_ID_SEQ_INC\" BEFORE INSERT ON \"USER\" FOR EACH ROW WHEN (new.USER_ID IS NULL) BEGIN SELECT SEQ_USER.nextval INTO :new.USER_ID FROM DUAL; END;");
} catch (SQLException e) {
logger.debug(e);
}
}
Creating triggers works with any type of JDBC driver; there must be something wrong with the SQL syntax -- which is odd because Oracle should report that when you run the CREATE TRIGGER (not when you use it the first time).
Since you use BEGIN ... END; make sure that you really have a ; after END in the SQL which you send to the DB.
If that isn't the cause, check this article.
I know this is a old post but here's my answer.
By default, Spring "initialize-database" instruction split the specified script by using the semicolon character : ";".
In a trigger, there often is a semicolon inside the trigger, thus the queries are badly splitted and executed.
The solution is to use another split character ("|" for example) like this :
<jdbc:initialize-database>
<jdbc:script location="classpath:myscript.sql" separator="|"/>
</jdbc:initialize-database>
Related
I am retrieving data from database using jdbc. In my code I am using 3-4 tables to get data. But sometimes if table is not present in database my code gives exception. How to handle this situation. I want my code to continue working for other tables even if one table is not present. Please help.
I have wrote a code like this
sql="select * from table"
now Result set and all.
If table is not present in database it give exception that no such table. I want to handle it. In this code I cannot take tables which are already present in advance . I want to check here itself if table is there or not.
Please do not mark it as a duplicate question. The link you shared doesnot give me required answer as in that question they are executing queries in database not through JDBC code
For Sybase ASE the easiest/quickest method would consist of querying the sysobjects table in the database where you expect the (user-defined) table to reside:
select 1 from sysobjects where name = 'table-name' and type = 'U'
if a record is returned => table exists
if no record is returned => table does not exist
How you use the (above) query is up to you ...
return a 0/1-row result set to your client
assign a value to a #variable
place in a if [not] exists(...) construct
use in a case statement
If you know for a fact that there won't be any other object types (eg, proc, trigger, view, UDF) in the database with the name in question then you could also use the object_id() function, eg:
select object_id('table-name')
if you receive a number => the object exists
if you receive a NULL => the object does not exist
While object_id() will obtain an object's id from the sysobjects table, it does not check for the object type, eg, the (above) query will return a number if there's a stored proc named 'table-name'.
As with the select/sysobjects query, how you use the function call in your code is up to you (eg, result set, populate #variable, if [not] exists() construct, case statement).
So, addressing the additional details provided in the comments ...
Assuming you're submitting a single batch that needs to determine table existence prior to running the desired query(s):
-- if table exists, run query(s); obviously if table does not exist then query(s) is not run
if exists(select 1 from sysobjects where name = 'table-name' and type = 'U')
begin
execute("select * from table-name")
end
execute() is required to keep the optimizer from generating an error that the table does not exist, ie, the query is not parsed/compiled unless the execute() is actually invoked
If your application can be written to use multiple batches, something like the following should also work:
# application specific code; I don't work with java but the gist of the operation would be ...
run-query-in-db("select 1 from sysobjects where name = 'table-name' and type = 'U'")
if-query-returns-a-row
then
run-query-in-db("select * from table-name")
fi
This is the way of checking if the table exists and drop it:
IF EXISTS (
SELECT 1
FROM sysobjects
WHERE name = 'a_table'
AND type = 'U'
)
DROP TABLE a_table
GO
And this is how to check if a table exists and create it.
IF NOT EXISTS (
SELECT 1
FROM sysobjects
WHERE name = 'a_table'
AND type = 'U'
)
EXECUTE("CREATE TABLE a_table (
col1 int not null,
col2 int null
)")
GO
(They are different because in table-drop a temporary table gets created, so if you try to create a new one you will get an exception that it already exists)
Before running the query which has some risk in table not existing, run the following sql query and check if the number of results is >= 1. if it is >= 1 then you are safe to execute the normal query. otherwise, do something to handle this situation.
SELECT count(*)
FROM information_schema.TABLES
WHERE (TABLE_SCHEMA = 'your_db_name') AND (TABLE_NAME = 'name_of_table')
I am no expert in Sybase but take a look at this,
exec sp_tables '%', '%', 'master', "'TABLE'"
Sybase Admin
I've been trying to create a trigger from java and it just won't work.
String trigger = String.format("CREATE TRIGGER `%s` AFTER %s ON %s BEGIN INSERT INTO `ndb_log` (`table_name`, `action`, `time`) VALUES ('%s', '%s', UNIX_TIMESTAMP()) END;",
name, this.event.toUppercase(), this.table, this.table, this.event.toLowercase());
CREATE TRIGGER `onnc_censorINSERT` AFTER INSERT ON nc_censor BEGIN INSERT INTO `ndb_log` (`table_name`, `action`, `time`) VALUES ('nc_censor', 'insert', UNIX_TIMESTAMP()); END;
com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'BEGIN INSERT INTO ndb_log (table_name, action, time) VALUES ('nc_censor' at line 1
I am not running this in phpMyAdmin, a server console or anything like that. I need to run it from java in a String. I call this.mysql.update(trigger); in my class which "basically" runs it.
I have tried running the create trigger string in ssh mysql, but it also doesn't work.
Two things: (1) you're missing the FOR EACH ROW clause of the trigger declaration; (2) you don't need the BEGIN and the END, because your trigger executes just one statement. Try this instead:
CREATE TRIGGER `onnc_censorINSERT` AFTER INSERT ON nc_censor FOR EACH ROW INSERT INTO `ndb_log` (`table_name`, `action`, `time`) VALUES ('nc_censor', 'insert', UNIX_TIMESTAMP());
I'm trying to get to grips with a Java app that talks to a SQL Server 2008 R2 DB. The app imports data into the DB, and it has a 'test mode'; the DB requests are wrapped up in a transaction, which is rolled back at the end.
With a particular dataset, the tool disables a trigger, and then re-enables it after the import. In test mode, on the first pass, everything works as expected - the dataset in 'imported' without problems. However, if I try to repeat the exercise, the app hangs at the point where it tries to disable the trigger.
Looking at SQL Profiler, I can see an RPC:Completed trace item, which suggests that SQL Server has received and successfully processed the request. At which point, I would expect the Java app to pick up control and continue -except that it doesn't, I'm struggling to think where to look next.
Java code:
String sql = "ALTER TABLE MyTable DISABLE TRIGGER ALL";
PreparedStatement stmt = mDBConnection.prepareStatement (sql);
stmt.execute();
Trace TextData:
declare #p1 int
set #p1=1
exec sp_prepare #p1 output,N'',N'ALTER TABLE MyTable DISABLE TRIGGER ALL',1
select #p1
Q: Any idea what the problem might be? Or any suggestions as to how I investigate further?
UPDATE:
Of course, the trace above only only shows the sp_prepare. There is a corresponding sp_execute statement - and the lack of RPC:Completed trace item, indicates that the problem is on SQL Servers side. A modified trace shows an RPC:Starting entry ('exec sp_execute 1'), but no matching RPC:Completed.
I can run sp_prepare & sp_execute in SSMS (providing I remove the set statement), as expected - it executes OK on the first pass after all.
Solution:
Using sp_who2 (see below), I could see that there the first connection/spid was blocked the second; on commit, the db connection was closed, but on rollback it wasn't. Since I'm running in test-and-rollback mode, this was the crux of my problem - closing the connection solved the problem.
sp_who2:
CREATE TABLE #sp_who2
(
SPID INT,
Status VARCHAR(1000) NULL,
Login SYSNAME NULL,
HostName SYSNAME NULL,
BlkBy SYSNAME NULL,
DBName SYSNAME NULL,
Command VARCHAR(1000) NULL,
CPUTime INT NULL,
DiskIO INT NULL,
LastBatch VARCHAR(1000) NULL,
ProgramName VARCHAR(1000) NULL,
SPID2 INT,
RequestID int
)
GO
INSERT INTO #sp_who2 EXEC sp_who2
GO
SELECT spid, status, blkby, command, ProgramName FROM #sp_who2 WHERE DBName = 'rio7_bch_test'
GO
DROP TABLE #sp_who2
GO
This very much sounds like you have locks that aren't released properly and block your DDL execution.
When your statement hangs, run the stored procedure sp_who2.
In the result of that procedure you'll which session is blocking your DDL and then you can take the approriate actions.
Don't use a PreparedStatement for this. Use just a plain Statement.
Statement stmt = mDBConnection.createStatement(sql);
The "ALTER TABLE" statement is DDL (Data Definition Language). DDL must wait for all DML (Data Manipulation Language) statements to complete. If you have an unclosed ResultSet, Statement, or PreparedStatement that is querying the table or a view upon that table, or a join with that table, or updating with auto-commit turned off - then that is DML that is not complete.
Before altering the table like this, ensure that every possible result set open on it has been explicitly closed, and similarly any statements. That will ensure that all DML is complete and DDL can be performed.
In general it is better to use PreparedStatements over Statements. A PreparedStatement is compiled once. A Statement every time it is executed. This means there is no difference for unparameterised statements like yours, and a potential benefit for any parameterised once.
Assuming a trusted JDBC implementation, there is no time a Statement might work when a PreparedStatement does not.
You may also find this question helpful.
I convert the DB from Oracle to MySQL.
I'm using both Java & Hibernate.
When I used oracle I had the following method that gave me a brand new and unused sequence value:
protected int getSequenceNextValue() {
Session session = sessionFactory.getCurrentSession();
Query query = session.createSQLQuery("select MY_SEQUENCE.NEXTVAL from DUAL");
return ((BigDecimal) query.uniqueResult()).intValueExact();
}
And I'm trying to refactor this method to work on MySQL DB.
I have a table in MySQL that I use as a sequence (through Hibernate):
create table MY_SEQUENCE(
next_val int(10) NOT NULL
);
Is there any thread safe way to get a new value from this table and in the same transction to increase it?
For most cases I use the Hibernate Generator to generate a new sequence using this table, but in several cases I need to do it manually.
The best solution for me will be a refactoring of the method above, in such way that threads that querying the table at the same time will not fail, but will wait for each other.
Thanks...
Have a look at the InnoDB table type and FOR UPDATE. An example similar to what you describe is in the MySQL manual here http://dev.mysql.com/doc/refman/5.0/en/innodb-locking-reads.html
I am using Spring's JdbcDaoSupport class with a DriverManagerDataSource using the MySQL Connector/J 5.0 driver (driverClassName=com.mysql.jdbc.driver). allowMultiQueries is set to true in the url.
My application is an in-house tool we recently developed that executes sql scripts in a directory one-by-one (allows us to re-create our schema and reference table data for a given date, etc, but I digress). The sql scripts sometime contain multiple statements (hence allowMultiQueries), so one script can create a table, add indexes for that table, etc.
The problem happens when including a statement to add a foreign key constraint in one of these files. If I have a file that looks like...
--(column/constraint names are examples)
CREATE TABLE myTable (
fk1 BIGINT(19) NOT NULL,
fk2 BIGINT(19) NOT NULL,
PRIMARY KEY (fk1, fk2)
);
ALTER TABLE myTable ADD CONSTRAINT myTable_fk1
FOREIGN KEY (fk1)
REFERENCES myOtherTable (id)
;
ALTER TABLE myTable ADD CONSTRAINT myTable_fk2
FOREIGN KEY (fk2)
REFERENCES myOtherOtherTable (id)
;
then JdbcTemplate.execute throws an UncategorizedSqlException with the following error message and stack trace:
Exception in thread "main" org.springframework.jdbc.UncategorizedSQLException: StatementCallback; uncategorized SQLException for SQL [ THE SQL YOU SEE ABOVE LISTED HERE ];
SQL state [HY000]; error code [1005]; Can't create table 'myDatabase.myTable' (errno: 150); nested exception is java.sql.SQLException: Can't create table 'myDatabase.myTable' (errno: 150)
at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:83)
at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:80)
at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:80)
and the table and foreign keys are not inserted.
Also, especially weird: if I take the foreign key statements out of the script I showed above and then place them in their own script that executes after (so I now have 1 script with just the create table statement, and 1 script with the add foreign key statements that executes after that) then what happens is:
tool executes create table script, works fine, table is created
tool executes add fk script, throws the same exception as seen above (except errno=121 this time), but the FKs actually get added (!!!)
In other words, when the create table/FK statements are in the same script then the exception is thrown and nothing is created, but when they are different scripts a nearly identical exception is thrown but both things get created.
Any help on this would be greatly appreciated. Please let me know if you'd like me to clarify anything more.
Some more info:
1) This only happens on my box. My coworker does not get the same problem.
2) The script that forces the tool to error works fine when executed from the mysql command line using the "script" command
My God.
http://bugs.mysql.com/bug.php?id=41635
and
[2nd link removed because spam filter isn't letting me add 2 links. Search Google for "mysql connector / j errno 150" and it's the 3rd result]
...
Looks like mySql5.1 has a bug with its jdbc connector where it bombs where an alter statement to add a FK is in a script with any other statement.
When I broke out my 3 statements into 3 scripts, it worked (the way I was trying before with the 2 fk statements in their own script still bombed because they were sharing a script!!). Also, my coworker is using MySql5.0, so it didn't affect him.
Holy Cow, that was a fun 5 hours.